83 results on '"Fleck RJ"'
Search Results
2. Evaluation of Pediatric Posterior Glottic Diastasis Using Dynamic Voice Computed Tomography.
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Noble AR, Fleck RJ, Maksimoski MT, McElfresh K, Kou YF, Tabangin ME, and de Alarcón A
- Abstract
Objectives: Posterior glottic diastasis (PGD) is an underappreciated etiology of dysphonia in patients with prior airway reconstruction or prolonged intubation. In endoscopic posterior cricoid reduction (ePCR), cricoid is removed to minimize the posterior glottic gap. Dynamic voice computed tomography (DVCT) permits visualization of the posterior glottis, estimating the amount of cricoid to be removed. Posterior glottic gaps in patients undergoing ePCR were compared to non-dysphonic patients to describe pediatric PGD and establish surgical parameters for ePCR., Methods: DVCTs performed in non-dysphonic patients and dysphonic patients undergoing ePCR from 2014 to 2023 were reviewed. EPCR operative reports were queried. Pre- and postoperative Pediatric Voice Handicap Index (pVHI) and Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) scores and aerodynamic measures were reviewed., Results: Seventeen pediatric patients who underwent ePCR and 19 non-dysphonic patients were included. Posterior glottic gaps were significantly larger in the dysphonic group (median 2.4 mm [IQR: 2.0, 2.8] vs. 1.3 mm [IQR: 1.1, 1.7], p < 0.001). Mean width of the cricoid removed was 1.6 mm (SD 0.4 mm). Mean (SD) pre- and postoperative pVHI scores were 55.5 (19.9) and 34.6 (16.0; p < 0.001). Mean (SD) pre- and postoperative CAPE-V scores were 52.7 (15.4) and 36.5 (20.4; p < 0.001), respectively., Conclusions: Children in this cohort tolerated an average 1.3 mm posterior glottic gap without dysphonia. Dysphonic patients with PGD had a median 2.4 mm gap and underwent cricoid reduction by 1.6 mm. All ePCR patients demonstrated improvement in dysphonia. Results seek to optimize the management of pediatric PGD and present a safe and effective amount of cricoid to remove during ePCR., Level of Evidence: 4 Laryngoscope, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)
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- 2024
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3. Pectus excavatum: the effect of tricuspid valve compression on cardiac function.
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Carroll MK, Powell AW, Hardie WD, Foster KE, Zhang B, Garcia VF, Vieira Alves VP, Brown RL, and Fleck RJ
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- Humans, Male, Female, Retrospective Studies, Adolescent, Child, Magnetic Resonance Imaging methods, Tricuspid Valve diagnostic imaging, Tricuspid Valve physiopathology, Adult, Young Adult, Funnel Chest diagnostic imaging, Funnel Chest complications, Funnel Chest physiopathology
- Abstract
Background: Pectus excavatum (PE) is a common congenital chest wall deformity with various associated health concerns, including psychosocial impacts, academic challenges, and potential cardiopulmonary effects., Objective: This study aimed to investigate the cardiac consequences of right atrioventricular groove compression in PE using cardiac magnetic resonance imaging., Materials and Methods: A retrospective analysis was conducted on 661 patients with PE referred for evaluation. Patients were categorized into three groups based on the degree of right atrioventricular groove compression (no compression (NC), partial compression (PC), and complete compression(CC)). Chest wall indices were measured: pectus index (PI), depression index (DI), correction index (CI), and sternal torsion., Results: The study revealed significant differences in chest wall indices between the groups: PE, NC=4.15 ± 0.94, PC=4.93 ± 1.24, and CC=7.2 ± 4.01 (P<0.0001). Left ventricle ejection fraction (LVEF) showed no significant differences: LVEF, NC=58.72% ± 3.94, PC=58.49% ± 4.02, and CC=57.95% ± 3.92 (P=0.0984). Right ventricular ejection fraction (RVEF) demonstrated significant differences: RVEF, NC=55.2% ± 5.3, PC=53.8% ± 4.4, and CC=53.1% ± 4.8 (P≥0.0001). Notably, the tricuspid valve (TV) measurement on the four-chamber view decreased in patients with greater compression: NC=29.52 ± 4.6; PC=28.26 ± 4.8; and CC=24.74 ± 5.73 (P<0.0001)., Conclusion: This study provides valuable insights into the cardiac consequences of right atrioventricular groove compression in PE and lends further evidence of mild cardiac changes due to PE., (© 2024. The Author(s).)
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- 2024
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4. Assessing Residual Gastric Fluid Volume after Administering Diluted Oral Contrast until One Hour Prior to Anesthesia in Children: An Observational Cohort Study.
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Narayanasamy S, Fleck RJ, Kandil AI, Afonya B, Mahmoud H, Lee J, Ding L, and Mahmoud MA
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Background: Gastric fluid volume has been used as a surrogate marker for pulmonary aspiration risk in studies evaluating fasting protocol safety. This study measured residual gastric fluid volume in children using a protocol in which diluted oral contrast medium was administered up until one hour before anesthesia. Methods: This was a single-center prospective observational cohort trial of 70 children for elective abdominal/pelvic computed tomography (CT). Imaging was performed after diluted enteral contrast medium administration, beginning two hours before and ending at least one hour before induction. For each patient, gastric fluid volume was calculated using an image region of interest. The primary outcome measure was gastric fluid volume measured using the computed tomography image. Results: The median time from the end of contrast administration to imaging was 1.5 h (range: 1.1 to 2.2 h). Residual gastric volume, measured using CT was <0.4 mL/Kg in 33%; ≥0.4 mL/Kg in 67%; and ≥1.5 mL/Kg in 44% of patients. Residual gastric volumes measured using CT and aspiration were moderately correlated (Spearman's correlation coefficient = 0.41, p = 0.0003). However, the median residual gastric volume measured using CT (1.17, IQR: 0.22 to 2.38 mL/Kg) was higher than that of aspiration (0.51, IQR: 0 to 1.58 mL/Kg, p = 0.0008 on differences in paired measures). Three cases of vomiting were reported. No evidence of pulmonary aspiration was identified. Conclusions: Children who receive large quantities of clear fluid up to one hour before anesthesia can have a significant gastric residual volume.
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- 2024
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5. Cardiothoracic Magnetic Resonance Angiography.
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Kocaoglu M, Pednekar A, Fleck RJ, and Dillman JR
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- Humans, Contrast Media, Heart, Magnetic Resonance Imaging, Imaging, Three-Dimensional methods, Magnetic Resonance Angiography methods, Ferrosoferric Oxide
- Abstract
Catheter-based angiography is regarded as the clinical reference imaging technique for vessel imaging; however, it is invasive and is currently used for intervention or physiologic measurements. Contrast enhanced magnetic resonance angiography (MRA) with gadolinium-based contrast agents can be performed as a three-dimensional (3D) MRA or as a time resolved 3D (4D) MRA without physiologic synchronization, in which case cardiac and respiratory motion may blur the edges of the vessels and cardiac chambers. Ferumoxytol has recently been a popular contrast agent for MRA in patients with chronic renal failure. Noncontrast 3D MRA with ECG gating and respiratory navigation are safe and accurate noninvasive cross-sectional imaging techniques for the visualization of great vessels of the heart and coronary arteries in a variety of cardiovascular disorders including complex congenital heart diseases. Noncontrast flow dependent MRA techniques such as time of flight, phase contrast, and black-blood MRA techniques can be used as complementary or primary techniques. Here we review both conventional and relatively new contrast enhanced and non-contrast enhanced MRA techniques including ferumoxytol enhanced MRA, and bright-blood and water-fat separation based noncontrast 3D MRA techniques., Competing Interests: Declaration of Competing Interest None, (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2024
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6. Characterization of Auricular Growth within the Pediatric Population Using Computed Tomography Scan Measurements.
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Leto Barone AA, Farley G, Vieira Alves VP, Bredemeier NO, Hogan E, Madzia J, Woodyard K, Schwentker AR, and Fleck RJ
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Background: In patients with microtia, auricular reconstruction is ideally performed promptly to prevent impaired socialization during formative childhood years. The earliest viable age for reconstruction is widely accepted from 7-10 years of age, as full auricular size is achieved around age 8, with some variability dependent on sex. This retrospective study aims to provide an auricular growth curve that accounts for age and sex, enhancing the individualized approach to ear reconstruction., Methods: A total of 319 images of unaffected patients who underwent computed tomography angiography of the head and neck were reviewed, with bilateral cartilage height and width measured according to a consensus-standardized image measurement protocol. Means and SDs of cartilage height and width were calculated for both sexes, and analysis of ear growth was performed through plotting the mean cartilage height, width, and width:height ratio over time., Results: Cartilage height and width differed significantly between male and female groups. Maximum cartilage height was reached at age 11 for female and at age 12 for male patients, whereas maximum cartilage width was reached at ages 10 and 8, respectively. On average, the width:height ratio for female group was 0.58. For male group, the average width:height ratio was 0.59., Conclusions: An auricular growth map was designed using computed tomography measurements demonstrating maximum auricular size at age 11 and 12 respectively for female and male patients, with both sexes having a width:height ratio maintained at approximately 0.6 throughout growth., Competing Interests: Disclosure statements are at the end of this article, following the correspondence information., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)
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- 2023
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7. Extracardiac Findings on Cardiac Magnetic Resonance: A Children's Hospital Experience.
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Trussell TM, Kocaoglu M, Fleck RJ, Taylor MD, Zang H, Ollberding NJ, and Lang SM
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- Humans, Child, Young Adult, Adult, Infant, Retrospective Studies, Magnetic Resonance Spectroscopy, Hospitals, Heart, Magnetic Resonance Imaging
- Abstract
Cardiac magnetic resonance (CMR) incorporates a field of view that has the potential to capture clinically relevant extracardiac findings (ECF); however, there has been minimal investigation of ECF prevalence in children's hospitals, where the patient population varies in age and diagnosis. We retrospectively reviewed consecutive, clinically indicated, CMR studies performed at a tertiary care children's hospital during a 1-year period from January 1 to December 31, 2019. ECFs were classified as significant or non-significant based on whether they were described in the final impression of the CMR report. A total of 851 distinct patients had a CMR study during the 1-year period. Mean age was 19.5 (range 0.2; 74.2) years. A total of 254 ECFs were present in 158 of the 851 studies (18.6%) with 9.8% of all studies having significant ECFs. A total of 40.2% of ECFs were previously unknown and 9.1% (23/254) of ECFs included further recommendations (2.1% of all studies). ECFs were most often found in the chest (48%) or abdomen/pelvis (46%). Three patients were incidentally found to have malignancy (renal cell, thyroid, and hepatocellular carcinoma). Comparing studies with significant ECFs to the group without, CMR indications for biventricular CHD (43% vs 31%, p = 0.036), single ventricle CHD (12% vs 3.9%, p = 0.002), and aortopathy/vasculopathy (16% vs 7.6%, p = 0.020) were more common. The odds of significant ECF increased with increasing age (OR 1.82, 95% CI 1.10-3.01) and increased most notably between ages 14 to 33 years old. Recognition of the high percentage of ECFs remains important for timely diagnosis of these incidental findings., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2023
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8. Correction to: Bronchopulmonary dysplasia from chest radiographs to magnetic resonance imaging and computed tomography: adding value.
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Higano NS, Bates AJ, Gunatilaka CC, Hysinger EB, Critser PJ, Hirsch R, Woods JC, and Fleck RJ
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- 2022
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9. Predicting tracheal work of breathing in neonates based on radiological and pulmonary measurements.
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Gunatilaka CC, Hysinger EB, Schuh A, Xiao Q, Gandhi DB, Higano NS, Ignatiuk D, Hossain MM, Fleck RJ, Woods JC, and Bates AJ
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- Humans, Infant, Newborn, Lung diagnostic imaging, Tidal Volume, Trachea diagnostic imaging, Tracheomalacia diagnostic imaging, Work of Breathing
- Abstract
Tracheomalacia is an airway condition in which the trachea excessively collapses during breathing. Neonates diagnosed with tracheomalacia require more energy to breathe, and the effect of tracheomalacia can be quantified by assessing flow-resistive work of breathing (WOB) in the trachea using computational fluid dynamics (CFD) modeling of the airway. However, CFD simulations are computationally expensive; the ability to instead predict WOB based on more straightforward measures would provide a clinically useful estimate of tracheal disease severity. The objective of this study is to quantify the WOB in the trachea using CFD and identify simple airway and/or clinical parameters that directly relate to WOB. This study included 30 neonatal intensive care unit subjects (15 with tracheomalacia and 15 without tracheomalacia). All subjects were imaged using ultrashort echo time (UTE) MRI. CFD simulations were performed using patient-specific data obtained from MRI (airway anatomy, dynamic motion, and airflow rates) to calculate the WOB in the trachea. Several airway and clinical measurements were obtained and compared with the tracheal resistive WOB. The maximum percent change in the tracheal cross-sectional area (ρ = 0.560, P = 0.001), average glottis cross-sectional area (ρ = -0.488, P = 0.006), minute ventilation (ρ = 0.613, P < 0.001), and lung tidal volume (ρ = 0.599, P < 0.001) had significant correlations with WOB. A multivariable regression model with three independent variables (minute ventilation, average glottis cross-sectional area, and minimum of the eccentricity index of the trachea) can be used to estimate WOB more accurately ( R
2 = 0.726). This statistical model may allow clinicians to estimate tracheal resistive WOB based on airway images and clinical data. NEW & NOTEWORTHY The work of breathing due to resistance in the trachea is an important metric for quantifying the effect of tracheal abnormalities such as tracheomalacia, but currently requires complex dynamic imaging and computational fluid dynamics simulation to calculate it. This study produces a method to predict the tracheal work of breathing based on readily available imaging and clinical metrics.- Published
- 2022
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10. The Severity of Pectus Excavatum Defect Is Associated With Impaired Cardiopulmonary Function.
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Zens TJ, Casar Berazaluce AM, Jenkins TM, Hardie W, Alsaied T, Tretter JT, Moore R, Foster K, Fleck RJ, Hanke RE, Colvin BE, Garrison AP, Kraemer A, Crotty E, Taylor M, Garcia VF, and Brown RL
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- Adolescent, Adult, Child, Heart Ventricles, Humans, Stroke Volume, Ventricular Function, Left, Ventricular Function, Right, Young Adult, Funnel Chest complications
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Background: Repair of pectus excavatum has cosmetic benefits, but the physiologic impact remains controversial. The aim of this study was to characterize the relationship between the degree of pectus excavatum and cardiopulmonary dysfunction seen on cardiac magnetic resonance (CMR) imaging, cardiopulmonary exercise testing (CPET), and pulmonary function testing (PFT)., Methods: A single-center analysis of CMR, CPET, and PFT was conducted. Regression models evaluated relationships between pectus indices and the clinical end points of cardiopulmonary function., Results: Data from 345 CMRs, 261 CPETs, and 281 PFTs were analyzed. Patients were a mean age of 15.2 ± 4 years, and 81% were aged <18 years. The right ventricular ejection fraction (RVEF) was <0.50 in 16% of patients, left ventricular ejection fraction (LVEF) was <0.55 in 22%, RVEF Z-score was < -2 in 32%, and the LVEF Z-score was < -2 in 18%. CPET revealed 33% of patients had reduced aerobic fitness. PFT results were abnormal in 23.1% of patients. Adjusted analyses revealed the Haller index had significant (P < .05) inverse associations with RVEF and LVEF., Conclusions: The severity of pectus excavatum is associated with ventricular systolic dysfunction. Pectus excavatum impacts right and left ventricular systolic function and can also impact exercise tolerance. The Haller index and correction index may be the most useful predictors of impairment., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
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- 2022
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11. Virtual Bronchoscopy of Neonatal Airway Malacia via High-Resolution, Respiratory-gated Magnetic Resonance Imaging.
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Higano NS, Gandhi DB, Xiao Q, Gunatilaka CC, Hysinger EB, Fleck RJ, Woods JC, and Bates AJ
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- Bronchoscopy methods, Humans, Infant, Newborn, Magnetic Resonance Imaging methods, Respiratory System, Bronchial Diseases, Tracheal Diseases
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- 2022
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12. Tracheostomy prediction model in neonatal bronchopulmonary dysplasia via lung and airway MRI.
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Adaikalam SA, Higano NS, Hysinger EB, Bates AJ, Fleck RJ, Schapiro AH, House MA, Nathan AT, Ahlfeld SK, Brady JM, Woods JC, and Kingma PS
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- Humans, Infant, Infant, Newborn, Infant, Premature, Lung diagnostic imaging, Magnetic Resonance Imaging methods, Prospective Studies, Tracheostomy, Bronchopulmonary Dysplasia diagnostic imaging, Bronchopulmonary Dysplasia therapy, Tracheomalacia
- Abstract
Rationale: Clinical management of neonatal bronchopulmonary dysplasia (BPD) is often imprecise and can vary widely between different institutions and providers, due to limited objective measurements of disease pathology severity. There is critical need to improve guidance on the application and timing of interventional treatments, such as tracheostomy., Objectives: To generate an imaging-based clinical tool for early identification of those patients with BPD who are likely to require later tracheostomy and long-term mechanical ventilation., Methods: We conducted a prospective cohort study of n = 61 infants (55 BPD, 6 preterm non-BPD). Magnetic resonance imaging (MRI) scores of lung parenchymal disease were used to create a binomial logistic regression model for predicting tracheostomy requirement. This model was further investigated using clinical variables and MRI-quantified tracheomalacia (TM)., Measurements and Main Results: A model for predicting tracheostomy requirement was created using MRI parenchymal score. This model had 89% accuracy, 100% positive predictive value (PPV), and 85% negative predictive value (NPV), compared with 84%, 60%, and 83%, respectively, when using only relevant clinical variables. In a subset of patients with airway MRI (n = 36), a model including lung and TM measurements had 83% accuracy, 92% PPV, and 78% NPV., Conclusions: MRI-based measurements of parenchymal disease and TM can be used to predict need for tracheostomy in infants with BPD, more accurately than clinical factors alone. This prediction model has strong potential as a clinical tool for physicians and families for early determination of tracheostomy requirement., (© 2022 Wiley Periodicals LLC.)
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- 2022
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13. Bronchopulmonary dysplasia from chest radiographs to magnetic resonance imaging and computed tomography: adding value.
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Higano NS, Bates AJ, Gunatilaka CC, Hysinger EB, Critser PJ, Hirsch R, Woods JC, and Fleck RJ
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- Female, Humans, Infant, Newborn, Magnetic Resonance Imaging adverse effects, Pregnancy, Tomography, X-Ray Computed adverse effects, Bronchopulmonary Dysplasia diagnostic imaging, Hypertension, Pulmonary, Premature Birth
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Bronchopulmonary dysplasia (BPD) is a common long-term complication of preterm birth. The chest radiograph appearance and survivability have evolved since the first description of BPD in 1967 because of improved ventilation and clinical strategies and the introduction of surfactant in the early 1990s. Contemporary imaging care is evolving with the recognition that comorbidities of tracheobronchomalacia and pulmonary hypertension have a great influence on outcomes and can be noninvasively evaluated with CT and MRI techniques, which provide a detailed evaluation of the lungs, trachea and to a lesser degree the heart. However, echocardiography remains the primary modality to evaluate and screen for pulmonary hypertension. This review is intended to highlight the important findings that chest radiograph, CT and MRI can contribute to precision diagnosis, phenotyping and prognosis resulting in optimal management and therapeutics., (© 2022. The Author(s).)
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- 2022
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14. Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline.
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Cristea AI, Ren CL, Amin R, Eldredge LC, Levin JC, Majmudar PP, May AE, Rose RS, Tracy MC, Watters KF, Allen J, Austin ED, Cataletto ME, Collaco JM, Fleck RJ, Gelfand A, Hayes D Jr, Jones MH, Kun SS, Mandell EW, McGrath-Morrow SA, Panitch HB, Popatia R, Rhein LM, Teper A, Woods JC, Iyer N, and Baker CD
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- Adolescent, Aftercare, Child, Chronic Disease, Humans, Infant, Infant, Newborn, Infant, Premature, Infant, Premature, Diseases therapy, Respiratory Tract Diseases therapy
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Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.
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- 2021
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15. Modern Lung Magnetic Resonance Imaging to Screen for Pulmonary Complications in Patients with Dyskeratosis Congenita.
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Walkup LL, Myers KC, Willmering MM, Mehta PA, Nelson AS, Fleck RJ, Woods JC, Davies SM, and Towe CT
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- Adolescent, Adult, Cohort Studies, Female, Humans, Magnetic Resonance Imaging, Male, Dyskeratosis Congenita complications, Dyskeratosis Congenita diagnostic imaging, Lung Diseases diagnostic imaging, Lung Diseases etiology
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- 2021
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16. Neonates With Tracheomalacia Generate Auto-Positive End-Expiratory Pressure via Glottis Closure.
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Gunatilaka CC, Hysinger EB, Schuh A, Gandhi DB, Higano NS, Xiao Q, Hahn AD, Fain SB, Fleck RJ, Woods JC, and Bates AJ
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- Female, Glottis diagnostic imaging, Humans, Infant, Newborn, Magnetic Resonance Imaging, Male, Tracheomalacia congenital, Tracheomalacia diagnostic imaging, Glottis physiopathology, Positive-Pressure Respiration, Tracheomalacia physiopathology
- Abstract
Background: In pediatrics, tracheomalacia is an airway condition that causes tracheal lumen collapse during breathing and may lead to the patient requiring respiratory support. Adult patients can narrow their glottis to self-generate positive end-expiratory pressure (PEEP) to raise the pressure in the trachea and prevent collapse. However, auto-PEEP has not been studied in newborns with tracheomalacia. The objective of this study was to measure the glottis cross-sectional area throughout the breathing cycle and to quantify total pressure difference through the glottis in patients with and without tracheomalacia., Research Question: Do neonates with tracheomalacia narrow their glottises? How does the glottis narrowing affect the total pressure along the airway?, Study Design and Methods: Ultrashort echo time MRI was performed in 21 neonatal ICU patients (11 with tracheomalacia, 10 without tracheomalacia). MRI scans were reconstructed at four different phases of breathing. All patients were breathing room air or using noninvasive respiratory support at the time of MRI. Computational fluid dynamics simulations were performed on patient-specific virtual airway models with airway anatomic features and motion derived via MRI to quantify the total pressure difference through the glottis and trachea., Results: The mean glottis cross-sectional area at peak expiration in the patients with tracheomalacia was less than half that in patients without tracheomalacia (4.0 ± 1.1 mm
2 vs 10.3 ± 4.4 mm2 ; P = .002). The mean total pressure difference through the glottis at peak expiration was more than 10 times higher in patients with tracheomalacia compared with patients without tracheomalacia (2.88 ± 2.29 cm H2 O vs 0.26 ± 0.16 cm H2 O; P = .005)., Interpretation: Neonates with tracheomalacia narrow their glottises, which raises pressure in the trachea during expiration, thereby acting as auto-PEEP., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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17. Outcomes of dexmedetomidine sedation for drug-induced sleep ciné magnetic resonance imaging studies in pediatric obstructive sleep apnea patients.
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Narayanasamy S, Winograd-Gomez V, Joshi H, Yang F, Ding L, Ishman SL, Fleck RJ, Patino M, and Mahmoud M
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- Child, Humans, Hypnotics and Sedatives adverse effects, Magnetic Resonance Imaging, Magnetic Resonance Imaging, Cine, Polysomnography, Retrospective Studies, Sleep, Dexmedetomidine adverse effects, Pharmaceutical Preparations, Sleep Apnea, Obstructive
- Abstract
Background: Dexmedetomidine is utilized as a sedative agent for drug-induced sleep cine magnetic resonance imaging studies due to its ability to mimic natural sleep and lack of respiratory depressant effects. The outcomes of dexmedetomidine sedation such as respiratory complications and unplanned admissions in obstructive sleep apnea patients undergoing these studies are currently unknown., Aim: To describe the outcomes of dexmedetomidine sedation for outpatient drug-induced sleep magnetic resonance imaging in pediatric patients with obstructive sleep apnea., Methods: This is a retrospective chart review conducted in pediatric patients with obstructive sleep apnea undergoing outpatient drug-induced sleep ciné magnetic resonance imaging studies with dexmedetomidine sedation. Demographics, comorbidities, polysomnography study results, vital signs, respiratory complications, airway interventions, successful completion of the scan, and unplanned hospital admissions were measured., Main Results: We analyzed 337 patients aged 2-18 years (median age of 11 years). The imaging was completed with dexmedetomidine as the sole sedative agent in 61% (N = 207) patients. Ketamine was administered as additional sedative agent in 36% (N = 122) of the patients. There was no difference in sedation-related adverse events and respiratory complications with regard to the severity of sleep apnea with the exception of mild desaturation episodes (SpO2 85%-90%). Patients who received additional sedative agents had significantly longer recovery room stay (71.5 [44] vs 55 [39] minutes; 95% CI of difference [9 to 23 min], p < 0.001) and total periprocedural stay (164.5 [52] vs 138 [64] minutes; 95% CI of difference [17 to 35 min], p < .001)., Conclusions: Dexmedetomidine alone or along with ketamine provided acceptable sedation in majority of the patients with obstructive sleep apnea undergoing outpatient diagnostic sleep magnetic resonance imaging studies without significant respiratory adverse events regardless of the severity of sleep apnea. Sedation failure and unplanned admissions are rare, and routine planned admission may not be required for this patient population., (© 2021 John Wiley & Sons Ltd.)
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- 2021
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18. Ventilatory limitations are not associated with dyspnea on exertion or reduced aerobic fitness in pectus excavatum.
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Hardie W, Powell AW, Jenkins TM, Foster K, Tretter JT, Fleck RJ, Garcia VF, and Brown RL
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- Dyspnea etiology, Exercise Test, Exercise Tolerance, Humans, Physical Exertion, Retrospective Studies, Funnel Chest diagnostic imaging
- Abstract
Exercise intolerance and chest pain are common symptoms in patients with pectus excavatum. To assess if the anatomic extent of pectus deformities determined by the correction index (CI) is associated with a pulmonary impairment at rest and during exercise we performed a retrospective review on pectus patients in our center who completed a symptom questionnaire, cardiopulmonary exercise test (CPET), pulmonary function tests (PFT), and chest magnetic resonance imaging. Of 259 patients studied, dyspnea on exertion and chest pain was reported in 64% and 41%, respectively. Peak oxygen uptake (VO
2 ) was reduced in 30% and classified as mild in two-thirds. A pulmonary limitation during exercise was identified in less than 3%. Ventilatory limitations on PFT was found in 26% and classified as mild in 85%. Obstruction was the most common abnormal pattern (11%). There were no differences between patients with normal or abnormal PFT patterns for the CI, VO2, or percentage reporting dyspnea or chest pain. Scatter plots demonstrated significant but weak inverse relationships between the CI and lung volumes at rest and during exercise. Multivariable linear regression modeling evaluating predictors of VO2 demonstrated positive associations with the forced expiratory volume at one second and a negative association with the CI. We conclude that resting PFT patterns have poor correlation with the anatomic extent of the pectus defect, symptomatology or aerobic fitness. Pulmonary limitations on CPET are uncommon and lung volumes during exercise are only minimally associated with the CI., (© 2021 Wiley Periodicals LLC.)- Published
- 2021
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19. Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model.
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Gandhi DB, Rice A, Gunatilaka CC, Higano NS, Fleck RJ, de Alarcon A, Hart CK, Kuo IC, Amin RS, Woods JC, Hysinger EB, and Bates AJ
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- Animals, Disease Models, Animal, Female, Imaging, Three-Dimensional, Intubation, Intratracheal, Laryngoscopy, Rabbits, Laryngostenosis diagnostic imaging, Magnetic Resonance Imaging methods
- Abstract
Objective/hypothesis: To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics., Study Design: Animal research study., Methods: Eight adult New-Zealand white rabbits were used as they approximate neonatal airway-size. The airways were measured using ETT-sizing and 3D UTE-MRI at baseline, 2 weeks post-cauterization induced SGS injury, and post-balloon dilation treatment. UTE-MR images were acquired to determine airway anatomy and motion. Airways were segmented from MR images. Cross-sectional area (CSA), major and minor diameters (D
major and Dminor ), and eccentricity were measured., Results: Post-injury CSA at SGS was significantly reduced (mean 38%) compared to baseline (P = .003) using UTE-MRI. ETT-sizing correlated significantly with MRI-measured CSA at the SGS location (r = 0.6; P < .01), particularly at the post-injury timepoint (r = 0.93; P < .01). Outer diameter from ETT-sizing (OD) correlated significantly with Dmajor (r = 0.63; P < .01) from UTE-MRI at the SGS location, especially for the post-injury timepoint (r = 0.91; P < .01). Mean CSA of upper trachea did not change significantly between end-expiration and end-inspiration at any timepoint (all P > .05). Eccentricity of the upper trachea increased significantly post-balloon dilation (P < .05)., Conclusions: UTE-MRI successfully detected SGS and treatment response in the rabbit model, with good correlation to ETT-sizing. Balloon dilation increased CSA at SGS, but not to baseline values. SGS did not alter dynamic motion for the trachea in this rabbit model; however, tracheas were significantly eccentric post-balloon dilation. UTE-MRI can detect SGS without sedation or ionizing radiation and may be a non-invasive alternative to ETT-sizing., Level of Evidence: NA Laryngoscope, 131:E1971-E1979, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)- Published
- 2021
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20. Effects on the Upper Airway Morphology with Intravenous Addition of Ketamine after Dexmedetomidine Administration in Normal Children.
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Mylavarapu G, Fleck RJ, Ok MS, Ding L, Kandil A, Amin RS, Das B, and Mahmoud M
- Abstract
General anesthesia decreases the tone of upper airway muscles in a dose-dependent fashion, potentially narrowing the pharyngeal airway. We examined the effects of adding ketamine on the airway configuration after dexmedetomidine administration in spontaneously breathing children with normal airways. 25 children presenting for Magnetic Resonance Imaging (MRI) of the brain/spine under general anesthesia were prospectively recruited in the study. Patients were anesthetized with dexmedetomidine bolus (2 mcg over 10 min) followed by dexmedetomidine infusion (2 mcg·kg-1·h) and ketamine and permitted to breathe spontaneously via the native airway. MR-CINE images of the upper airway were obtained with dexmedetomidine infusion alone (baseline) and 5, 10, and 15 min after administering ketamine bolus (2 mg·kg-1) in two anatomical axial planes at the nasopharynx and the retroglossal upper airway. Airway lumen is segmented with a semi-automatic image processing approach using a region-growing algorithm. Outcome measures of cross-sectional area, transverse and anterior-posterior diameters of the airway in axial planes at the level of the epiglottis in the retroglossal airway, and in the superior nasopharynx were evaluated for changes in airway size with sedation. Airway dimensions corresponding to the maximum, mean, and minimum sizes during a respiratory cycle were obtained to compare the temporal changes in the airway size. The dose-response of adding ketamine to dexmedetomidine alone condition on airway dimensions were examined using mixed-effects of covariance models. 22/25 patients based on inclusion/exclusion criteria were included in the final analysis. The changes in airway measures with the addition of ketamine, when compared to the baseline of dexmedetomidine alone, were statistically insignificant. The modest changes in airway dimensions are clinically less impactful and within the accuracy of the semi-automatic airway segmentation approach. The effect sizes were small for most airway measures. The duration of ketamine seems to not affect the airway size. In conclusion, adding ketamine to dexmedetomidine did not significantly reduce upper airway configuration when compared to dexmedetomidine alone.
- Published
- 2020
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21. The chest wall gender divide: females have better cardiopulmonary function and exercise tolerance despite worse deformity in pectus excavatum.
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Casar Berazaluce AM, Jenkins TM, Garrison AP, Hardie WD, Foster KE, Alsaied T, Tretter J, Moore RA, Fleck RJ, Garcia VF, and Brown RL
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Female, Funnel Chest epidemiology, Humans, Incidence, Magnetic Resonance Imaging, Male, Sex Factors, United States epidemiology, Young Adult, Exercise Tolerance physiology, Funnel Chest physiopathology, Heart Rate physiology, Stroke Volume physiology, Thoracic Wall physiopathology, Ventricular Function, Left physiology
- Abstract
Purpose: Pectus excavatum (PE) is a chest wall deformity of variable severity and symptomatology. Existing female-specific literature highlights breast asymmetry and cosmetic reconstruction. We sought to evaluate gender differences in cardiopulmonary function., Methods: Cardiac MRIs, pulmonary function tests (PFTs), and cardiopulmonary exercise tests (CPETs) were reviewed in 345 patients undergoing preoperative evaluation for PE. Regression modeling was used to evaluate associations between gender and clinical endpoints of cardiopulmonary function., Results: Mean age was 15.2 years, 19% were female, 98% were white. Pectus indices included median Haller Index (HI) of 4.8, mean depression index (DI) of 0.63, correction index (CI) of 33.6%, and Cardiac Compression Index (CCI) of 2.79. Cardiac assessment revealed decreased right and left ventricular ejection fraction (RVEF, LVEF) in 16% and 22% of patients, respectively. PFTs and CPETs were abnormal in ~ 30% of patients. While females had deeper PE deformities-represented by higher pectus indices-they had superior function with higher RVEF, LVEF Z-scores, FEV
1 , VO2 max, O2 pulse, work, and breathing reserve (p < 0.05)., Conclusion: Despite worse PE deformity and symptomatology, females had a better cardiopulmonary function and exercise tolerance than males. Further research is needed to assess the precise mechanisms of this phenomenon and postoperative outcomes in this population.- Published
- 2020
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22. Increased Work of Breathing due to Tracheomalacia in Neonates.
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Gunatilaka CC, Higano NS, Hysinger EB, Gandhi DB, Fleck RJ, Hahn AD, Fain SB, Woods JC, and Bates AJ
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- Humans, Magnetic Resonance Imaging, Respiration, Trachea, Work of Breathing, Tracheomalacia
- Abstract
Rationale: Dynamic collapse of the tracheal lumen (tracheomalacia) occurs frequently in premature neonates, particularly in those with common comorbidities such as bronchopulmonary dysplasia. The tracheal collapse increases the effort necessary to breathe (work of breathing [WOB]). However, quantifying the increased WOB related to tracheomalacia has previously not been possible. Therefore, it is also not currently possible to separate the impact of tracheomalacia on patient symptoms from parenchymal abnormalities. Objectives: To measure the increase in WOB due to airway motion in individual subjects with and without tracheomalacia and with different types of respiratory support. Methods: Fourteen neonatal intensive care unit subjects not using invasive mechanical ventilation were recruited. In eight, tracheomalacia was diagnosed via clinical bronchoscopy, and six did not have tracheomalacia. Self-gated three-dimensional ultrashort-echo-time magnetic resonance imaging (MRI) was performed on each subject with clinically indicated respiratory support to obtain cine images of tracheal anatomy and motion during the respiratory cycle. The component of WOB due to resistance within the trachea was then calculated via computational fluid dynamics (CFD) simulations of airflow on the basis of the subject's anatomy, motion, and respiratory airflow rates. A second CFD simulation was performed for each subject with the airway held static at its largest (i.e., most open) position to determine the increase in WOB due to airway motion and collapse. Results: The tracheal-resistive component of WOB was increased because of airway motion by an average of 337% ± 295% in subjects with tracheomalacia and 24% ± 14% in subjects without tracheomalacia ( P < 0.02). In the tracheomalacia group, subjects who were treated with continuous positive airway pressure (CPAP) using a RAM cannula expended less energy for breathing compared with the subjects who were breathing room air or on a high-flow nasal cannula. Conclusions: Neonatal subjects with tracheomalacia have increased energy expenditure compared with neonates with normal airways, and CPAP may be able to attenuate the increase in respiratory work. Subjects with tracheomalacia expend more energy on the tracheal-resistive component of WOB alone than nontracheomalacia patients expend on the resistive WOB for the entire respiratory system, according to previously reported values. CFD may be able to provide an objective measure of treatment response for children with tracheomalacia.
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- 2020
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23. Structural lung abnormalities on computed tomography correlate with asthma inflammation in bronchoscopic alveolar lavage fluid.
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Roach DJ, Ruangnapa K, Fleck RJ, Rattan MS, Zhang Y, Hossain MM, Guilbert TW, and Woods JC
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- Adolescent, Asthma immunology, Bronchoalveolar Lavage Fluid cytology, Case-Control Studies, Child, Child, Preschool, Eosinophils immunology, Feasibility Studies, Female, Humans, Infant, Infant, Newborn, Leukocyte Count, Male, Neutrophils immunology, Respiratory Function Tests, Retrospective Studies, Severity of Illness Index, Young Adult, Asthma diagnosis, Bronchoalveolar Lavage Fluid immunology, Lung diagnostic imaging, Tomography, X-Ray Computed
- Abstract
Objective : Image scoring systems have been developed to assess the severity of specific lung abnormalities in patients diagnosed with various pulmonary diseases except for asthma. A comprehensive asthma imaging scoring system may identify specific abnormalities potentially linking these to inflammatory phenotypes. Methods : Computed tomography (CT) images of 88 children with asthma (50 M/38 F, mean age 7.8 ± 5.4 years) acquired within 12 months of bronchoscopic alveolar lavage fluid (BALF) sampling that assessed airway inflammation cell types were reviewed along with CT images of 49 controls (27 M/22 F, mean age 3.4 ± 2.2 years). Images were scored using a comprehensive scoring system to quantify bronchiectasis (BR), bronchial wall thickening (BWT), ground glass opacity, mucus plugging (MP), consolidations, linear densities (LD), and air trapping (AT). Each category was scored 0-2 in each of six lobar regions (with lingula separated from left upper lobe). Results : Absolute average overall scores of the controls and children with asthma were 0.72 ± 1.59 and 5.39 ± 5.83, respectively ( P < 0.0001). Children with asthma scored significantly higher for BR ( N = 20, 0.33 ± 0.80, P = 0.0002), BWT ( N = 28, 0.72 ± 1.40, P < 0.0001), MP ( N = 28, 0.37 ± 1.12, P = 0.0052), consolidation ( N = 31, 0.67 ± 1.22, P < 0.0001), LD ( N = 58, 1.12 ± 1.44, P < 0.0001), and AT ( N = 52, 1.78 ± 2.31, P < 0.0001). There was a significant difference between the BR score of children with positive inflammatory response in BALF ( N = 53) and those who were negative for airway inflammation cells (0.14 ± 0.36, P = 0.040). Conclusions : Significant lung structural abnormalities were readily identified on CT of children with asthma, with image differentiation of those with an inflammatory response on BALF. Chest imaging demonstrates potential as a noninvasive clinical tool for additional characterization of asthma phenotypes.
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- 2020
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24. Safety and cost of drug-induced sleep endoscopy outside the operating room.
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Bergeron M, Lee DR, DeMarcantonio MA, Kandil A, Mahmoud MA, Fleck RJ, and Ishman SL
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- Adenoidectomy, Adolescent, Child, Child, Preschool, Female, Humans, Laryngoscopy adverse effects, Male, Operating Rooms, Prospective Studies, Sleep, Tonsillectomy, Anesthesia, Costs and Cost Analysis, Laryngoscopy economics, Laryngoscopy methods, Sleep Apnea, Obstructive diagnosis, Sleep Apnea, Obstructive surgery
- Abstract
Introduction: Drug-induced sleep endoscopy (DISE) is used to assess site of obstruction for patients in a pharmacologically induced sleep-like state. It is traditionally performed in the operating room (OR), however, no data exists regarding the feasibility of this intervention outside the OR in children. The objective is to compare the safety of DISE performed in the MRI induction room to those performed in the OR., Methods: Prospective case-series of patients undergoing DISE in the MRI induction room (study group) to those assessed in the OR (controls) in a single-institution pediatric tertiary care center. Consecutive patients undergoing DISE examination for persistent obstructive sleep apnea (OSA) after adenotonsillectomy from September 2016 to September 2017 were included., Results: Overall, 118 patients (38 study patients, 80 controls) with a mean age of 10.6 years (95% confidence interval [CI], 9.3-11.9) underwent DISE; 39.8% (47/118) were female. The most frequent comorbidity was cardiac disease (22.0%, 26/118). The mean obstructive apnea-hypopnea index was 12.2 events/hour (95% CI, 8.8-15.6) for controls and 13.5 events/hour (95% CI, 8.7-18.3) for study patients (P = .76). No major complication or unplanned admissions occurred in either group. Induction time was similar (12 vs. 13 minutes, P = .7) as was total procedure time (12 vs. 14 minutes, P = .3) for procedures performed in both settings., Conclusion: There were no significant complications for DISE performed in the OR or the MRI induction room and procedure times were similar. Further assessment of patient outcomes and resource utilization is needed., Level of Evidence: 4 Laryngoscope, 130: 2076-2080, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)
- Published
- 2020
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25. Cardiovascular magnetic resonance imaging derived septal curvature in neonates with bronchopulmonary dysplasia associated pulmonary hypertension.
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Critser PJ, Higano NS, Lang SM, Kingma PS, Fleck RJ, Hirsch R, Taylor MD, and Woods JC
- Subjects
- Antihypertensive Agents therapeutic use, Bronchopulmonary Dysplasia complications, Bronchopulmonary Dysplasia physiopathology, Bronchopulmonary Dysplasia therapy, Female, Humans, Hypertension, Pulmonary etiology, Hypertension, Pulmonary physiopathology, Hypertension, Pulmonary therapy, Infant, Newborn, Length of Stay, Male, Predictive Value of Tests, Pulmonary Artery drug effects, Respiratory Therapy, Retrospective Studies, Severity of Illness Index, Time Factors, Treatment Outcome, Ventricular Septum drug effects, Ventricular Septum physiopathology, Arterial Pressure drug effects, Bronchopulmonary Dysplasia diagnostic imaging, Hypertension, Pulmonary diagnostic imaging, Magnetic Resonance Imaging, Cine, Pulmonary Artery physiopathology, Vascular Resistance drug effects, Ventricular Septum diagnostic imaging
- Abstract
Background: Bronchopulmonary dysplasia (BPD) associated with pulmonary hypertension (PH) is a significant source of morbidity and mortality in premature infants. Recent advances have allowed the use of cardiovascular magnetic resonance (CMR) in the assessment of respiratory and cardiac disease in infants with BPD. In adults and older pediatric patients, decreased CMR interventricular septal curvature correlates with increased mean pulmonary artery pressure and pulmonary vascular resistance. The current study sought to determine the relationship of CMR derived septal curvature in neonates with BPD and BPD-PH with a need for PH therapy., Methods: Forty moderate or severe BPD and 12 mild BPD or control infants were imaged without contrast between 38 and 47 weeks post-menstrual age on a neonatal-sized, neonatal intensive care unit-sited 1.5 T CMR scanner. CMR indices including eccentricity index (CMR-EI) and septal curvature were measured and compared to BPD severity and clinical outcomes including hospital length of stay (LOS), duration of respiratory support, respiratory support level at discharge and PH therapy., Results: CMR-EI was directly associated and septal curvature was inversely associated with BPD severity. In a univariate analysis, CMR-EI and septal curvature were associated with increased hospital LOS, duration of respiratory support, respiratory support at hospital discharge, and need for PH therapy. In multivariable analysis CMR-EI was associated with hospital LOS and duration of respiratory support and septal curvature was associated with respiratory support at hospital discharge. Septal curvature was the only clinical or CMR variable associated with need for PH therapy (R
2 = 0.66, p = 0.0014) in multivariable analysis demonstrating improved discrimination beyond CMR-EI., Conclusions: CMR derived septal curvature correlates significantly with clinical outcomes including hospital LOS, duration of respiratory support, respiratory support level at hospital discharge, and PH therapy in neonates with BPD and BPD-PH. Further, CMR derived septal curvature demonstrated improved discrimination of need for PH therapy and respiratory support at discharge compared to clinical variables and other CMR indices, supporting septal curvature as a non-invasive marker of PH in this population with potential to guide management strategies.- Published
- 2020
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26. Pilot Study to Assess the Use of Ultrasound in Evaluating the Abnormal Pediatric Airway.
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Bell JR, Cohen AP, Graff JT, Fleck RJ, O'Hara S, de Alarcon A, and Hart CK
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- Adolescent, Child, Child, Preschool, Feasibility Studies, Female, Glottis surgery, Humans, Laryngostenosis surgery, Male, Pilot Projects, Retrospective Studies, Trachea surgery, Tracheal Stenosis surgery, Glottis diagnostic imaging, Laryngostenosis diagnosis, Otorhinolaryngologic Surgical Procedures methods, Plastic Surgery Procedures methods, Trachea diagnostic imaging, Tracheal Stenosis diagnosis, Ultrasonography methods
- Abstract
In this study, we sought to explore the feasibility of using ultrasonography to evaluate airway anomalies in awake children with previous airway reconstruction. For the month of December 2018, we reviewed the medical records of patients aged <18 years old with prior airway reconstruction who had an outpatient appointment and a microlaryngoscopy and bronchoscopy within 24 hours of each other. Four patients met inclusion criteria and were enrolled. Sonographic airway images and measurements were obtained during the outpatient appointment and compared with those obtained during endoscopy. Ultrasound identified extraluminal stents and glottic, subglottic, and tracheal pathology. Subglottic measurements obtained sonographically were within 0.1 to 0.5 mm of the outer diameter of the appropriate endotracheal tubes. Ultrasound did not visualize tracheotomy tubes or posterolateral pathology. Our findings lay the foundation for expanding the role of ultrasound in pediatric airway assessment, keeping in mind its apparent inability to visualize posterolateral airway pathology.
- Published
- 2020
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27. Author Correction: Left atrial dysfunction in sickle cell anemia is associated with diffuse myocardial fibrosis, increased right ventricular pressure and reduced exercise capacity.
- Author
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Alsaied T, Niss O, Tretter JT, Powell AW, Chin C, Fleck RJ, Cnota JF, Malik P, Quinn CT, Nagueh SF, Taylor MD, and Mazur WM
- Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
- Published
- 2020
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28. Ultrashort Echo-Time MRI for the Assessment of Tracheomalacia in Neonates.
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Hysinger EB, Bates AJ, Higano NS, Benscoter D, Fleck RJ, Hart CK, Burg G, De Alarcon A, Kingma PS, and Woods JC
- Subjects
- Bronchopulmonary Dysplasia epidemiology, Bronchoscopy, Comorbidity, Esophageal Atresia epidemiology, Exhalation, Female, Hernias, Diaphragmatic, Congenital epidemiology, Humans, Infant, Infant, Newborn, Inhalation, Male, Predictive Value of Tests, ROC Curve, Reproducibility of Results, Tracheoesophageal Fistula epidemiology, Tracheomalacia diagnosis, Tracheomalacia epidemiology, Magnetic Resonance Imaging methods, Respiratory-Gated Imaging Techniques methods, Trachea diagnostic imaging, Tracheomalacia diagnostic imaging
- Abstract
Background: Bronchoscopy is the gold standard for evaluating tracheomalacia; however, reliance on an invasive procedure limits understanding of normal airway dynamics. Self-gated ultrashort echo-time MRI (UTE MRI) can assess tracheal dynamics but has not been rigorously evaluated., Methods: This study was a validation of UTE MRI diagnosis of tracheomalacia in neonates using bronchoscopy as the gold standard. Bronchoscopies were reviewed for the severity and location of tracheomalacia based on standardized criteria. The percent change in cross-sectional area (CSA) of the trachea between end-inspiration and end-expiration was determined by UTE MRI, and receiver-operating curves were used to determine the optimal cutoff values to predict tracheomalacia and determine positive and negative predictive values., Results: Airway segments with tracheomalacia based on bronchoscopy had a more than threefold change in CSA measured from UTE MRI (54.4 ± 56.1% vs 14.8 ± 19.5%; P < .0001). UTE MRI correlated moderately with bronchoscopy for tracheomalacia severity (ρ = 0.39; P = .0001). Receiver-operating curves, however, showed very good ability of UTE MRI to identify tracheomalacia (area under the curve, 0.78). A "loose" definition (> 20% change in CSA) of tracheomalacia had good sensitivity (80%) but low specificity (64%) for identifying tracheomalacia based on UTE MRI, whereas a "strict" definition (> 40% change in CSA) was poorly sensitive (48%) but highly specific (93%)., Conclusions: Self-gated UTE MRI can noninvasively assess tracheomalacia in neonates without sedation, ionizing radiation, or increased risk. This technique overcomes major limitations of other diagnostic modalities and may be suitable for longitudinal population studies of tracheal dynamics., (Copyright © 2020. Published by Elsevier Inc.)
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- 2020
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29. Left atrial dysfunction in sickle cell anemia is associated with diffuse myocardial fibrosis, increased right ventricular pressure and reduced exercise capacity.
- Author
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Alsaied T, Niss O, Tretter JT, Powell AW, Chin C, Fleck RJ, Cnota JF, Malik P, Quinn CT, Nagueh SF, Taylor MD, and Mazur WM
- Abstract
Increased extracellular volume (ECV) by CMR is a marker of interstitial myocardial fibrosis and is associated with diastolic dysfunction in sickle cell anemia (SCA). Left atrial (LA) dysfunction and stiffness contribute to the development of diastolic heart failure in other settings. We aimed to evaluate LA function and stiffness associations with ECV, tricuspid regurgitation jet velocity (TRV) and exercise abnormalities in SCA. In a prospective study, individuals with SCA underwent CMR, echocardiography and exercise test. ECV was measured using MOLLI sequence. Atrial strain was studied in the 4- and 2-chamber views. LA stiffness was calculated as the ratio of echocardiographic E/e'-to-LA reservoir strain. Twenty-four participants with SCA were included (median age 20 years). ECV was increased in participant with SCA compared to our lab normal values (mean 0.44 ± 0.08 vs 0.26 ± 0.02, P < 0.0001). Six (25%) had LA LGE. ECV positively correlated with LA stiffness (r = 0.45, p = 0.04). There was a negative correlation between LA stiffness and %predicted VO2 (r = -0.50, p = 0.04). LA stiffness was moderately associated with increased TRV (r = 0.55, p < 0.005). LA stiffness is associated with ECV, exercise impairment and increased TRV. This study sheds insights on the interaction between LA function, RV hypertension, and myocardial fibrosis in SCA.
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- 2020
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30. Cardiac Magnetic Resonance Imaging Evaluation of Neonatal Bronchopulmonary Dysplasia-associated Pulmonary Hypertension.
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Critser PJ, Higano NS, Tkach JA, Olson ES, Spielberg DR, Kingma PS, Fleck RJ, Lang SM, Moore RA, Taylor MD, and Woods JC
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- Female, Humans, Infant, Infant, Newborn, Infant, Premature, Male, Bronchopulmonary Dysplasia diagnostic imaging, Bronchopulmonary Dysplasia physiopathology, Hypertension, Pulmonary diagnostic imaging, Hypertension, Pulmonary physiopathology, Infant, Newborn, Diseases diagnostic imaging, Infant, Newborn, Diseases physiopathology, Magnetic Resonance Imaging methods
- Abstract
Rationale: Patients with bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension (PH) have increased morbidity and mortality. Noninvasive assessment relies on echocardiograms (echos), which are technically challenging in this population. Improved assessment could augment decisions regarding PH therapies. Objectives: We hypothesized that neonatal cardiac magnetic resonance imaging (MRI) will correlate with BPD severity and predict short-term clinical outcomes, including need for PH therapies for infants with BPD. Methods: A total of 52 infants (31 severe BPD, 9 moderate BPD, and 12 with either mild or no BPD) were imaged between 39 and 47 weeks postmenstrual age on a neonatal-sized, neonatal ICU-sited 1.5-T magnetic resonance (MR) scanner. MR left ventricular eccentricity index (EI), main pulmonary artery-to-aorta (PA/AO) diameter ratio, and pulmonary arterial blood flow were determined. Echos obtained for clinical indications were reviewed. MRI and echo indices were compared with BPD severity and clinical outcomes, including length of stay (LOS), duration of respiratory support, respiratory support at discharge, and PH therapy. Measurements and Main Results: PA/AO ratio increased with BPD severity. Increased PA/AO ratio, MR-EI, and echo-EIs were associated with increased LOS and duration of respiratory support. No correlation was seen between pulmonary arterial blood flow and BPD outcomes. Controlling for gestational age, birth weight, and BPD severity, MR-EI was associated with LOS and duration of respiratory support. Increased PA/AO ratio and MR-EI were associated with PH therapy during hospitalization and at discharge. Conclusions: MRI can provide important image-based measures of cardiac morphology that relate to disease severity and clinical outcomes in neonates with BPD.
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- 2020
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31. The Value of Dynamic Voice CT Scan for Complex Airway Patients Undergoing Voice Surgery.
- Author
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Bergeron M, Fleck RJ, Zacharias SRC, Tabangin ME, and de Alarcon A
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- Adolescent, Child, Clinical Decision-Making, Dysphonia etiology, Dysphonia physiopathology, Endoscopy, Female, Humans, Male, Retrospective Studies, Treatment Outcome, Vocal Cords physiopathology, Voice Quality, Young Adult, Dysphonia diagnostic imaging, Dysphonia surgery, Plastic Surgery Procedures, Tomography, X-Ray Computed, Vocal Cords diagnostic imaging, Vocal Cords surgery
- Abstract
Introduction: Dynamic voice computerized tomography (DVCT) is a novel technique that provides additional information to characterize laryngeal function for patients with complex airway history that may alter surgical decisions. The goal of this study was to evaluate the impact of DVCT on decision making for reconstructive voice surgery for a cohort of post-airway reconstruction dysphonia patients., Methods: Retrospective chart review at a pediatric tertiary care center for patients with history of complex airway surgery and subsequent reconstructive voice surgery for dysphonia between 2010 and 2016. The study group had a DVCT prior to surgery while the control group underwent surgery without a DVCT. Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and pediatric Voice Handicap Index (pVHI) scores were evaluated by the voice clinic team (otolaryngologist, speech therapist) before and after voice surgery., Results: Twenty-one patients were analyzed (14 female, 67%) with a mean age (SD) of 14 (4.5) years old. Ninety percent (17/21) had a prior tracheostomy and a mean (SD) of 2.6 (1.3) airway surgeries. Twelve patients (57%) underwent DVCT prior to reconstructive voice surgery. CAPE-V baseline scores were similar between study and controls (means [SE] = 49 [4.6] and 57 [6.0], P = .72). However, scores significantly improved for the study group after voice surgery (mean [SE] = 31 (4.7), P < .0001) while controls did not improve (58 [5.7], P = .99). Baseline VHI scores were similar between both groups: mean (SE) = 54 (5.4) versus 52 (6.2), respectively, P = .99. Postsurgically, VHI scores were also similar between both groups (means [SE]: 46 [7.1] vs 47 [4.5], P = .99). Reconstructive voice surgery for study patients included posterior cricoid reduction (46%), vocal fold medialization/augmentation (46%), and laryngeal reinnervation (7.7%) while all controls underwent a single treatment (vocal fold medialization/augmentation)., Conclusion: Patients with preoperative DVCT were more likely to have improvement. DVCT appeared to have altered surgical decision making and has allowed tailoring of reconstructive surgery to specific patients' needs. DVCT could represent an important tool prior to reconstructive surgery to guide the choice of surgical procedures for complex airway patients.
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- 2019
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32. mDixon ECG-gated 3-dimensional cardiovascular magnetic resonance angiography in patients with congenital cardiovascular disease.
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Kourtidou S, Jones MR, Moore RA, Tretter JT, Ollberding NJ, Crotty EJ, Rattan MS, Fleck RJ, and Taylor MD
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- Adolescent, Adult, Artifacts, Child, Child, Preschool, Contrast Media administration & dosage, Female, Humans, Infant, Male, Meglumine administration & dosage, Organometallic Compounds administration & dosage, Predictive Value of Tests, Reproducibility of Results, Retrospective Studies, Young Adult, Aorta diagnostic imaging, Aortic Diseases diagnostic imaging, Cardiac-Gated Imaging Techniques, Coronary Vessels diagnostic imaging, Electrocardiography, Heart Defects, Congenital diagnostic imaging, Imaging, Three-Dimensional, Magnetic Resonance Angiography
- Abstract
Background: Cardiovascular magnetic resonance (CMR) angiography (CMRA) is an important non-invasive imaging tool for congenital heart disease (CHD) and aortopathy patients. The conventional 3D balanced steady-state free precession (bSSFP) sequence is often confounded by imaging artifacts. We sought to compare the respiratory navigated and electrocardiogram (ECG) gated modified Dixon (mDixon) CMRA sequence to conventional non-gated dynamic multi-phase contrast enhanced CMRA (CE-CMRA) and bSSFP across a variety of diagnoses., Methods: We included 24 patients with CHD or aortopathy with CMR performed between September 2017 to December 2017. Each patient had undergone CE-CMRA, followed by a bSSFP and mDixon angiogram. Patients with CMR-incompatible implants or contraindications to contrast were excluded. The studies were rated according to image quality at a scale from 1 (poor) to 4 (excellent) based on diagnostic adequacy, artifact burden, vascular border delineation, myocardium-blood pool contrast, and visualization of pulmonary and systemic veins and coronaries. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and quantitative vascular measurements were compared between the two gated sequences. Bland-Altman plots were generated to compare paired measures., Results: All scans were diagnostically adequate. Mean (SD) quality scores were 3.4 (0.7) for the mDixon, 3.2 (0.5) for the bSSFP and 3.4 (0.5) for the CE-CMRA. Qualitatively, the intracardiac anatomy and myocardium-blood pool definition were better in the bSSFP; however, mDixon images showed enhanced vessel wall sharpness with less blurring surrounding the anatomical borders distally. Coronary origins were identified in all cases. Pulmonary veins were visualized in 92% of mDixon sequences, 75% of bSSFP and 96% of CE-CMRA. Similarly, neck veins were identified in 92, 83 and 96% respectively. Artifacts prevented vascular measurement in 6/192 (3%) and 4/192 (2%) of total vascular measurements for the mDixon and bSSFP, respectively. However, the size of signal void and field distortion were significantly worse in the latter, particularly for flow and metal induced artifacts., Conclusion: In patients with congenital heart disease, ECG gated mDixon angiography yields high fidelity vascular images including better delineation of head and neck vasculature and pulmonary veins and fewer artifacts than the comparable bSSFP sequence. It should be considered as the preferred strategy for successful CHD imaging in patients with valve stenosis, vascular stents, or metallic implants.
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- 2019
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33. Elevated lung volumes in neonates with bronchopulmonary dysplasia measured via MRI.
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Yoder LM, Higano NS, Schapiro AH, Fleck RJ, Hysinger EB, Bates AJ, Kingma PS, Merhar SL, Fain SB, and Woods JC
- Subjects
- Humans, Infant, Newborn, Lung Volume Measurements, Magnetic Resonance Imaging methods, Bronchopulmonary Dysplasia diagnostic imaging, Lung diagnostic imaging
- Abstract
Background: Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity defined by requirement for respiratory support at 36 weeks postmenstrual age (PMA), but structural sequelae like lung hyperinflation are often not quantified. Quiet-breathing, nonsedated magnetic resonance imaging (MRI) allows tomographic quantification of lung volumes and densities. We hypothesized that functional residual capacity (FRC) and intrapleural volume (IV) are increased in BPD and correlate with qualitative radiological scoring of hyperinflation., Methods: Ultrashort echo time (UTE) MRI of 17 neonates (acquired at ~39 weeks PMA) were reconstructed at end-expiration and end-inspiration via the time course of the k
0 point in k-space. Images were segmented to determine total lung, tidal, parenchymal tissue, and vascular tissue volumes. FRC was calculated by subtracting parenchymal and vascular tissue volumes from IV. Respiratory rate (RR) was calculated via the UTE respiratory waveform, yielding estimates of minute ventilation when combined with tidal volumes (TVs). Two radiologists scored hyperinflation on the MR images., Results: IV at FRC increased in BPD: for control, mild, and severe (patients the median volumes were 32.8, 33.5, and 50.9 mL/kg, respectively. TV (medians: 2.21, 3.64, and 4.84 mL/kg) and minute ventilation (medians: 493, 750, and 991 mL/min) increased with increasing severity of BPD (despite decreasing RR, medians: 75.6, 63.0, and 56.1 breaths/min). FRC increased with increasing severity of BPD (39.3, 38.3, and 56.0 mL, respectively). Findings were consistent with increased hyperinflation scored by radiologists., Conclusions: This study demonstrates that UTE MRI can quantify hyperinflation in neonatal BPD and that lung volumes significantly increase with disease severity., (© 2019 Wiley Periodicals, Inc.)- Published
- 2019
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34. Assessment of liver T1 mapping in fontan patients and its correlation with magnetic resonance elastography-derived liver stiffness.
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Ramachandran P, Serai SD, Veldtman GR, Lang SM, Mazur W, Trout AT, Dillman JR, Fleck RJ, Taylor MD, Alsaied T, and Moore RA
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- Adult, Female, Humans, Liver diagnostic imaging, Male, Retrospective Studies, Young Adult, Elasticity Imaging Techniques methods, Fontan Procedure, Liver Cirrhosis diagnostic imaging, Magnetic Resonance Imaging methods, Postoperative Complications diagnostic imaging
- Abstract
Objectives: To explore the utility of liver T1 mapping in Fontan patients and its correlation to magnetic resonance elastography (MRE)-derived liver stiffness., Background and Aims: Liver disease is a major long-term extra cardiac complication in the Fontan population. MRE is frequently used to quantify liver stiffness in Fontan patients; however, it has certain limitations. Native T1 mapping by cardiac magnetic resonance (CMR) is useful in assessment of cardiac fibrosis, but its potential in evaluating liver fibrosis and its correlation to MRE-derived liver stiffness in Fontan patients have not been reported., Methods: Fontan patients who underwent CMR and MRE were included. Liver Native T1, extracellular volume (ECV) and delta coefficients were measured and correlated with MRE-derived liver stiffness in all Fontan patients. Native liver T1 in Fontan patients were compared to normal controls with biventricular circulation and no known liver disease., Results: A total of 17 Fontan patients and 7 normal controls were included in this study. Fontan patients had significantly higher liver native T1 (690 ± 41 ms vs 620 ± 35 ms; p < 0.001) as compared to controls. There was strong positive correlation between MRE derived liver stiffness and liver native T1 (r = 0.81, p < 0.001)., Conclusions: Liver native T1 was significantly elevated in Fontan patients compared to controls and strongly correlated with MRE-derived liver stiffness. This technique may prove to be a useful noninvasive imaging biomarker for assessing liver fibrosis in the Fontan population.
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- 2019
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35. Abnormal submaximal cardiopulmonary exercise parameters predict impaired peak exercise performance in sickle cell anemia patients.
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Powell AW, Alsaied T, Niss O, Fleck RJ, Malik P, Quinn CT, Mays WA, Taylor MD, and Chin C
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- Adolescent, Adult, Cardiomyopathies diagnosis, Case-Control Studies, Female, Follow-Up Studies, Humans, Incidence, Longitudinal Studies, Male, Ohio epidemiology, Prognosis, Prospective Studies, Respiratory Function Tests, Young Adult, Anemia, Sickle Cell physiopathology, Cardiomyopathies epidemiology, Exercise, Exercise Test, Oxygen metabolism, Oxygen Consumption
- Abstract
Purpose: Sickle cell anemia (SCA) patients frequently have many comorbidities, including diastolic dysfunction (DD) and exercise intolerance. SCA patients often cannot reach maximal effort on exercise testing; little is known regarding whether submaximal exercise parameters can predict abnormal maximal exercise results in SCA patients and if there are any possible associations with DD., Methods: A prospective longitudinal study was performed in SCA patients. All patients had a resting cardiac MRI (CMR), cardiopulmonary exercise test (CPET) with cycle ergometry using a ramp protocol, and an echocardiogram. Exercise data were compared with age-, gender-, and size-matched normal controls., Results: Compared with normal controls, the SCA group (n = 19) had lower mean max oxygen consumption (VO
2 ; 1378 ± 412 mL/min vs 2237 ± 580, P < 0.01) and workload (117 ± 37.6 watts vs 175 ± 50.5 watts, P = 0.0003). When evaluating the submaximal exercise parameters, there was lower VO2 at the anaerobic threshold (AT; 950 ± 311.7 vs 1460 ± 409.9, P < 0.01) and oxygen uptake efficiency slope (OUES) at AT (1512 ± 426.2 vs 2080 ± 339, P < 0.01). The max VO2 strongly correlated with VO2 at AT (r = 0.9, P < 0.01) and OUES (r = 0.83, P < 0.01) at AT. The VO2 at AT correlated with hematocrit (r = 0.77, P < 0.05). The OUES correlated with left ventricular ejection fraction by CMR (r = 0.55, P = 0.01), hematocrit (r = 0.52, P = 0.02), and lateral E/e' (r = -0.54, P = 0.01)., Conclusions: SCA patients have abnormal submaximal exercise measures compared with controls, which is strongly associated with abnormal maximal exercise results. The degree of submaximal abnormality correlates with DD abnormalities by echocardiography. These data expand the scope of functional cardiovascular abnormalities in SCA., (© 2019 Wiley Periodicals, Inc.)- Published
- 2019
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36. Assessing the relationship between movement and airflow in the upper airway using computational fluid dynamics with motion determined from magnetic resonance imaging.
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Bates AJ, Schuh A, Amine-Eddine G, McConnell K, Loew W, Fleck RJ, Woods JC, Dumoulin CL, and Amin RS
- Subjects
- Adult, Computer Simulation, Humans, Magnetic Resonance Imaging, Male, Models, Anatomic, Models, Biological, Motion, Hydrodynamics, Lung physiopathology, Movement, Respiration, Trachea physiopathology
- Abstract
Background: Computational fluid dynamics simulations of respiratory airflow in the upper airway reveal clinically relevant information, including sites of local resistance, inhaled particle deposition, and the effect of pathological constrictions. Unlike previous simulations, which have been performed on rigid anatomical models from static medical imaging, this work utilises ciné imaging during respiration to create dynamic models and more closely represent airway physiology., Methods: Airway movement maps were obtained from non-rigid image registration of fast-cine MRI and applied to high-spatial-resolution airway surface models. Breathing flowrates were recorded simultaneously with imaging. These data formed the boundary conditions for large eddy simulation computations of the airflow from exterior mask to bronchi. Simulations with rigid geometries were performed to demonstrate the resulting airflow differences between airflow simulations in rigid and dynamic airways., Findings: In the analysed rapid breathing manoeuvre, incorporating airway movement significantly changed the findings of the CFD simulations. Peak resistance increased by 19.8% and occurred earlier in the breath. Overall pressure loss decreased by 19.2%, and the proportion of flow in the mouth increased by 13.0%. Airway wall motion was out-of-phase with the air pressure force, demonstrating the presence of neuromuscular motion. In total, the anatomy did 25.2% more work on the air than vice versa., Interpretations: Realistic movement of the airway is incorporated into CFD simulations of airflow in the upper airway for the first time. This motion is vital to producing clinically relevant computational models of respiratory airflow and will allow novel analysis of dynamic conditions, such as sleep apnoea., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
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- 2019
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37. Endoscopic posterior cricoid reduction: A surgical method to improve posterior glottic diastasis.
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de Alarcón A, Zacharias S, Oren L, de Luzan CF, Tabangin ME, Cohen AP, Roetting NJ, and Fleck RJ
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- Adolescent, Child, Computer Simulation, Female, Humans, Hydrodynamics, Imaging, Three-Dimensional, Male, Preoperative Period, Retrospective Studies, Treatment Outcome, Cricoid Cartilage surgery, Glottis, Laryngeal Diseases surgery, Laryngoscopy methods
- Abstract
Objectives/hypothesis: Describe the preoperative evaluation of patients with glottic diastasis who are candidates for endoscopic posterior cricoid reduction (EPCR) and their perioperative and postoperative surgical and voice outcomes, and validate the aerodynamic benefit of EPCR using computation fluid dynamics (CFD)-based modeling from computed tomography (CT) scans., Study Design: Retrospective case series., Methods: Thirteen patients who underwent EPCR were followed from 2013 to 2017. They received a preoperative voice evaluation, microlaryngoscopy and bronchoscopy, dynamic voice CT (performed on patients seen from 2014 to study completion), and postoperative voice evaluation (n = 12). Postoperative inpatient days, complications, and postoperative endoscopic intervention were collected. To validate the aerodynamic benefit of EPCR, CFD modeling was carried out on one patient., Results: Thirteen patients (nine females, nine with intubation injury, and four with post-airway reconstruction dysphonia) underwent EPCR at a mean age of 11.0 years. The mean preoperative and postoperative Pediatric Voice handicap Index scores were 53.8 and 33.8, respectively (P = .006). Mean maximum phonation time preoperatively and postoperatively was 5.3 and 6.7, respectively (P = .04). Of eight patients who underwent preoperative CT imaging, all demonstrated a posterior gap. Modeling demonstrated a change in flow and pressure. The mean hospital stay was 2.4 days. Nine patients underwent postoperative endoscopic intervention, and one experienced a complication that resolved with intervention., Conclusions: Patients who underwent EPCR for dysphonia following intubation or airway reconstruction showed improvements in vocal efficiency, loudness, and perceived voice handicapping. Their hospital stay was brief, with few complications. CFD modeling corroborated these clinical findings. EPCR thus warrants consideration in the management of patients with posterior glottic diastasis., Level of Evidence: 4 Laryngoscope, 129:S1-S9, 2019., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)
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- 2019
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38. Quantitative Assessment of Regional Dynamic Airway Collapse in Neonates via Retrospectively Respiratory-Gated 1 H Ultrashort Echo Time MRI.
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Bates AJ, Higano NS, Hysinger EB, Fleck RJ, Hahn AD, Fain SB, Kingma PS, and Woods JC
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- Bronchoscopy methods, Comorbidity, Female, Hernias, Diaphragmatic, Congenital diagnostic imaging, Humans, Image Processing, Computer-Assisted, Infant, Newborn, Intensive Care, Neonatal, Male, Prospective Studies, Respiration, Treatment Outcome, Bronchopulmonary Dysplasia diagnostic imaging, Magnetic Resonance Imaging methods, Tracheomalacia diagnostic imaging
- Abstract
Background: Neonatal dynamic tracheal collapse (tracheomalacia, TM) is a common and serious comorbidity in infants, particularly those with chronic lung disease of prematurity (bronchopulmonary dysplasia, BPD) or congenital airway or lung-related conditions such as congenital diaphragmatic hernia (CDH), but the underlying pathology, impact on clinical outcomes, and response to therapy are not well understood. There is a pressing clinical need for an accurate, objective, and safe assessment of neonatal TM., Purpose: To use retrospectively respiratory-gated ultrashort echo-time (UTE) MRI to noninvasively analyze moving tracheal anatomy for regional, quantitative evaluation of dynamic airway collapse in quiet-breathing, nonsedated neonates., Study Type: Prospective., Population/subjects: Twenty-seven neonatal subjects with varying respiratory morbidities (control, BPD, CDH, abnormal polysomnogram)., Field Strength/sequence: High-resolution 3D radial UTE MRI (0.7 mm isotropic) on 1.5T scanner sited in the neonatal intensive care unit., Assessment: Images were retrospectively respiratory-gated using the motion-modulated time-course of the k-space center. Tracheal surfaces were generated from segmentations of end-expiration/inspiration images and analyzed geometrically along the tracheal length to calculate percent-change in luminal cross-sectional area (A
% ) and ratio of minor-to-major diameters at end-expiration (rD,exp ). Geometric results were compared to clinically available bronchoscopic findings (n = 14)., Statistical Tests: Two-sample t-test., Results: Maximum A% significantly identified subjects with/without a bronchoscopic TM diagnosis (with: 46.9 ± 10.0%; without: 27.0 ± 5.8%; P < 0.001), as did minimum rD,exp (with: 0.346 ± 0.146; without: 0.671 ± 0.218; P = 0.008). Subjects with severe BPD exhibited a far larger range of minimum rD,exp than subjects with mild/moderate BPD or controls (0.631 ± 0.222, 0.782 ± 0.075, and 0.776 ± 0.030, respectively), while minimum rD,exp was reduced in CDH subjects (0.331 ± 0.171) compared with controls (P < 0.001)., Data Conclusion: Respiratory-gated UTE MRI can quantitatively and safely evaluate neonatal dynamic tracheal collapse, as validated with the clinical standard of bronchoscopy, without requiring invasive procedures, anesthesia, or ionizing radiation., Level of Evidence: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:659-667., (© 2018 International Society for Magnetic Resonance in Medicine.)- Published
- 2019
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39. Non-contrast three-dimensional gradient recalled echo Dixon-based magnetic resonance angiography/venography in children.
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Dillman JR, Trout AT, Merrow AC, Moore RA, Rattan MS, Crotty EJ, Fleck RJ, Yoneyama M, Wang H, and Tkach JA
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- Child, Humans, Image Enhancement methods, Imaging, Three-Dimensional, Magnetic Resonance Angiography methods, Respiratory-Gated Imaging Techniques
- Abstract
Magnetic resonance imaging (MRI) has been considered a valuable diagnostic tool for noninvasive imaging of the vasculature in children and adults for more than two decades. While a variety of non-contrast MRI methods have been described for imaging of both arteries and veins (e.g., time-of-flight, phase contrast, and balanced steady-state free precession imaging), contrast-enhanced magnetic resonance angiography/venography are the most commonly employed vascular imaging techniques due to their high spatial and contrast resolutions and general reliability. In this technical innovation article, we describe a novel 3-D respiratory-triggered gradient recalled echo Dixon-based MR angiography/MR venography technique that provides high-resolution anatomical imaging of the vasculature of the neck, body and extremities without the need for intravenous contrast material or breath-holding.
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- 2019
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40. A novel method to generate dynamic boundary conditions for airway CFD by mapping upper airway movement with non-rigid registration of dynamic and static MRI.
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Bates AJ, Schuh A, McConnell K, Williams BM, Lanier JM, Willmering MM, Woods JC, Fleck RJ, Dumoulin CL, and Amin RS
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- Adult, Child, Humans, Male, Respiratory Mechanics, Computer Simulation, Magnetic Resonance Imaging, Models, Biological, Movement, Respiratory System diagnostic imaging, Respiratory System physiopathology, Sleep Apnea, Obstructive diagnostic imaging, Sleep Apnea, Obstructive physiopathology
- Abstract
Computational fluid dynamics (CFD) simulations of airflow in the human airways have the potential to provide a great deal of information that can aid clinicians in case management and surgical decision making, such as airway resistance, energy expenditure, airflow distribution, heat and moisture transfer, and particle deposition, as well as the change in each of these due to surgical interventions. However, the clinical relevance of CFD simulations has been limited to date, as previous models either did not incorporate neuromuscular motion or any motion at all. Many common airway pathologies, such as obstructive sleep apnea (OSA) and tracheomalacia, involve large movements of the structures surrounding the airway, such as the tongue and soft palate. Airway wall motion may be due to many factors including neuromuscular motion, internal aerodynamic forces, and external forces such as gravity. Therefore, to realistically model these airway diseases, a method is required to derive the airway wall motion, whatever the cause, and apply it as a boundary condition to CFD simulations. This paper presents and validates a novel method of capturing in vivo motion of airway walls from magnetic resonance images with high spatiotemporal resolution, through a novel combination of non-rigid image, surface, and surface-normal-vector registration. Coupled with image-synchronous pneumotachography, this technique provides the necessary boundary conditions for dynamic CFD simulations of breathing, allowing the effect of the airway's complex motion to be calculated for the first time, in both normal subjects and those with conditions such as OSA., (© 2018 John Wiley & Sons, Ltd.)
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- 2018
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41. Neonatal Pulmonary Magnetic Resonance Imaging of Bronchopulmonary Dysplasia Predicts Short-Term Clinical Outcomes.
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Higano NS, Spielberg DR, Fleck RJ, Schapiro AH, Walkup LL, Hahn AD, Tkach JA, Kingma PS, Merhar SL, Fain SB, and Woods JC
- Subjects
- Bronchopulmonary Dysplasia therapy, Female, Humans, Infant, Newborn, Infant, Premature, Lung diagnostic imaging, Lung physiopathology, Male, Predictive Value of Tests, Premature Birth, Reproducibility of Results, Severity of Illness Index, Time Factors, Bronchopulmonary Dysplasia diagnostic imaging, Bronchopulmonary Dysplasia physiopathology, Magnetic Resonance Imaging methods, Respiration, Artificial methods
- Abstract
Rationale: Bronchopulmonary dysplasia (BPD) is a serious neonatal pulmonary condition associated with premature birth, but the underlying parenchymal disease and trajectory are poorly characterized. The current National Institute of Child Health and Human Development (NICHD)/NHLBI definition of BPD severity is based on degree of prematurity and extent of oxygen requirement. However, no clear link exists between initial diagnosis and clinical outcomes., Objectives: We hypothesized that magnetic resonance imaging (MRI) of structural parenchymal abnormalities will correlate with NICHD-defined BPD disease severity and predict short-term respiratory outcomes., Methods: A total of 42 neonates (20 severe BPD, 6 moderate, 7 mild, 9 non-BPD control subjects; 40 ± 3-wk postmenstrual age) underwent quiet-breathing structural pulmonary MRI (ultrashort echo time and gradient echo) in a neonatal ICU-sited, neonatal-sized 1.5 T scanner, without sedation or respiratory support unless already clinically prescribed. Disease severity was scored independently by two radiologists. Mean scores were compared with clinical severity and short-term respiratory outcomes. Outcomes were predicted using univariate and multivariable models, including clinical data and scores., Measurements and Main Results: MRI scores significantly correlated with severities and predicted respiratory support at neonatal ICU discharge (P < 0.0001). In multivariable models, MRI scores were by far the strongest predictor of respiratory support duration over clinical data, including birth weight and gestational age. Notably, NICHD severity level was not predictive of discharge support., Conclusions: Quiet-breathing neonatal pulmonary MRI can independently assess structural abnormalities of BPD, describe disease severity, and predict short-term outcomes more accurately than any individual standard clinical measure. Importantly, this nonionizing technique can be implemented to phenotype disease, and has potential to serially assess efficacy of individualized therapies.
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- 2018
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42. Using T1 mapping in cardiovascular magnetic resonance to assess congestive hepatopathy.
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Kazour I, Serai SD, Xanthakos SA, and Fleck RJ
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- Adolescent, Adult, Child, Child, Preschool, Contrast Media, Disease Progression, Female, Heart Diseases surgery, Humans, Image Interpretation, Computer-Assisted, Infant, Infant, Newborn, Male, Retrospective Studies, Heart Diseases complications, Liver Diseases diagnostic imaging, Liver Diseases etiology, Magnetic Resonance Imaging methods
- Abstract
The goal of this study was to assess the ability of quantitative T1 cardiovascular magnetic resonance (CMR) imaging to calculate liver extracellular volume (ECV) in patients with varying degrees of congestive hepatopathy (CH). T1 measurements and ECV calculations were performed retrospectively in three cohorts of patients: normal cardiac function, tetralogy of fallot (TOF) repair and Fontan palliation. All CMR studies included modified look-locker inversion recovery (MOLLI) T1 mapping scans performed pre- and post-injection of a gadolinium-based contrast agent (GBCA). Pixel intensity data were manually collected from images of the liver and cardiac blood pool to determine contrast-induced changes in T1 for liver and blood. These data were then used to compute liver ECV. 172 subjects were included in the study. Of these, 140 subjects were normal cardiac function patients, 16 were TOF repair patients and 16 patients were with Fontan palliation. A statistically significant difference in both the liver native T1 and ECV measurements was found between patients with normal cardiac function vs. Fontan palliation patients (p < 0.01). Our data indicate that measuring T1 maps both pre- and post-GBCA injection within CMR scan session can be used to follow progression of liver fibrosis. This technique has the potential to improve diagnosis and treatment of patients with chronic liver disease and liver fibrosis.
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- 2018
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43. Measuring liver T2* and cardiac T2* in a single acquisition.
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Serai SD, Trout AT, Fleck RJ, Quinn CT, and Dillman JR
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- Child, Female, Humans, Image Enhancement methods, Male, Retrospective Studies, Heart diagnostic imaging, Iron Overload diagnostic imaging, Liver diagnostic imaging, Magnetic Resonance Imaging methods
- Abstract
Purpose: The purpose of this study is determine if both liver T2* and cardiac T2* can be measured on a single breath-hold acquisition., Materials and Methods: For this IRB-approved retrospective study, 137 patients with dedicated Cardiac MRI and Liver MRI examinations obtained sequentially on 1.5T scanners and on the same day were included for analysis. Both the cardiac and liver MRI examinations utilized GRE sequences for quantification of tissue iron. Specifically, T2* was measured using an 8-echo, multi-echo gradient echo single breath-hold sequence. Liver T2* was measured in a blinded manner on images from each of the cardiac and dedicated liver MRI examinations and were correlated. Bland-Altman difference plot was used to assess mean bias., Results: 137 examinations from 93 subjects met inclusion criteria. 10 examination pairs were excluded because the first echo time (TE) on the cardiac MRI was insufficiently short for the very high liver iron content. After exclusion, 127 studies from 89 subjects (67.4% males) were included in the final analysis. The mean subject age (± standard deviation) was 11.5 ± 7.5 years (range 0-29.3 years; median 10.5 years). Mean liver T2* measured on cardiac MRI was 8.3 ± 7.7 ms and mean liver T2* measured on dedicated liver MRI was 7.8 ± 7.4 ms (p < 0.001). There was strong positive correlation between the two liver T2* measurements (r = 0.989, p < 0.0001; 95% CI 0.985-0.992). With the exception of borderline outliers, all values fell within two standard deviations on the Bland-Altman difference plots, with a mean bias of 0.5 ms (range - 1.8 to + 2.7 ms)., Conclusion: In most patients with suspected or known iron overload, a single breath-hold GRE sequence may be sufficient to evaluate the iron concentration (T2*) of both the myocardium and the liver.
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- 2018
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44. Preliminary Assessment of Dynamic Voice CT in Post-Airway Reconstruction Patients.
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Bergeron M, Fleck RJ, Middlebrook C, Zacharias S, Tolson S, Oren L, Smith D, and de Alarcon A
- Subjects
- Adolescent, Child, Cohort Studies, Confidence Intervals, Dysphonia etiology, Female, Humans, Male, Point-of-Care Testing, Plastic Surgery Procedures methods, Retrospective Studies, Sensitivity and Specificity, Stroboscopy methods, Tertiary Care Centers, Young Adult, Airway Obstruction surgery, Dysphonia diagnosis, Laryngoscopy methods, Plastic Surgery Procedures adverse effects, Tomography, X-Ray Computed methods, Voice Quality
- Abstract
Objectives To compare the ability of the dynamic voice computed tomography (CT) scan to characterize laryngeal function in airway reconstruction patients vs bedside endoscopic nasopharyngolaryngoscopy and videolaryngostroboscopy. Study Design Case series with chart review. Settings Pediatric tertiary care center. Subjects and Methods Retrospective case series of children and young adults with a history of complex airway surgeries with subsequent dysphonia. We analyzed clinical data for all patients who underwent an airway reconstruction procedure between January 1, 2010, and April 30, 2016, and also had a dynamic voice CT and bedside endoscopic exam during the same period. Results Twenty-four patients were analyzed (4 male, 20 female) with a mean age of 15.1 years (95% confidence interval [CI], 12.9-17.22). Patients had a mean of 2.2 airway surgeries (95% CI, 1.8-2.6), with 62.5% of them being open procedures. Laryngotracheoplasty with a cartilage graft was the most common procedure (40.0%). The pattern of laryngeal closure could be detected in all cases with the dynamic CT scan (n = 24/24, 100%) compared to 87.5% (21/24) with the standard endoscopic examination ( P = .04). The location of gap closure could be detected in all cases (24/24) with the dynamic voice CT while 20.8% (5/24 patients) could not be rated with standard endoscopy/stroboscopy ( P = .02). Dynamic voice CT was able to assess the vertical closure pattern of the glottis 100% (24/24) while it could be detected in 83.3% (20/24) cases with endoscopic study ( P = .04). Conclusion Dynamic voice CT shows promise as an additional tool for evaluation of patients with a history of complex airway procedures by providing complementary information.
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- 2018
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45. Diastolic dysfunction is associated with exercise impairment in patients with sickle cell anemia.
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Alsaied T, Niss O, Powell AW, Fleck RJ, Cnota JF, Chin C, Malik P, Quinn CT, and Taylor MD
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- Adolescent, Adult, Child, Female, Humans, Male, Oxygen Consumption, Prospective Studies, Young Adult, Anemia, Sickle Cell physiopathology, Diastole physiology, Exercise, Ventricular Dysfunction, Left physiopathology
- Abstract
Background: Left ventricular diastolic dysfunction (DD) is an independent risk factor for mortality in sickle cell anemia (SCA) and is associated with increased extracellular volume (ECV) on cardiac MRI (CMR). Exercise impairment is common in SCA, but its causes and prognostic value are not well understood., Objective: To study the effects of DD and ECV on cardiopulmonary exercise test (CPET) in patients with SCA., Methods and Results: As part of a prospective study to characterize the cardiomyopathy of SCA (NCT02410811), 20 children and adults with SCA underwent CMR, echocardiography, and cycle ergometer CPET (age range 8-43 years). Maximum exercise was reached in 18 patients and 17 (94%) had reduced exercise capacity (%predicted VO
2 less than 80%). Six patients had DD and none had systolic dysfunction. Patients with DD had lower exercise capacity compared to patients with normal diastolic function (%predicted VO2 48.2 ± 9.1% vs. 61.2 ± 11.7%; P = 0.01). The z-score of left ventricular lateral E/e' ratio, which is a marker of DD, was negatively associated with %predicted VO2 (r = -0.61, P = 0.01). All patients with moderate-to-severe exercise impairment (%predicted VO2 < 60%) had lateral E/e' z-score > 2. In a multivariate analysis, lateral E/e' z-score was independently associated with %predicted VO2 (P = 0.02). All participants had elevated ECV but the degree of elevation was not associated with exercise parameters., Conclusion: Left ventricular DD is associated with decreased exercise capacity in SCA. Interventions to prevent or delay DD could improve exercise capacity, quality of life, and long-term outcomes in SCA., (© 2018 Wiley Periodicals, Inc.)- Published
- 2018
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46. Magnetic resonance imaging of obstructive sleep apnea in children.
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Fleck RJ, Shott SR, Mahmoud M, Ishman SL, Amin RS, and Donnelly LF
- Subjects
- Adenoidectomy, Child, Continuous Positive Airway Pressure, Humans, Polysomnography, Sleep Apnea, Obstructive etiology, Sleep Apnea, Obstructive therapy, Tonsillectomy, Magnetic Resonance Imaging methods, Sleep Apnea, Obstructive diagnostic imaging
- Abstract
Sleep-disordered breathing has a spectrum of severity that spans from snoring and partial airway collapse with increased upper airway resistance, to complete upper airway obstruction with obstructive sleep apnea during sleeping. While snoring occurs in up to 20% of children, obstructive sleep apnea affects approximately 1-5% of children. The obstruction that occurs in obstructive sleep apnea is the result of the airway collapsing during sleep, which causes arousal and impairs restful sleep. Adenotonsillectomy is the first-line treatment of obstructive sleep apnea and is usually effective in otherwise healthy nonsyndromic children. However, there are subgroups in which this surgery is less effective. These subgroups include children with obesity, severe obstructive sleep apnea preoperatively, Down syndrome, craniofacial anomalies and polycystic ovarian disease. Continuous positive airway pressure (CPAP) is the first-line therapy for persistent obstructive sleep apnea despite previous adenotonsillectomy, but it is often poorly tolerated by children. When CPAP is not tolerated or preferred by the family, surgical options beyond adenotonsillectomy are discussed with the parent and child. Dynamic MRI of the airway provides a means to identify and localize the site or sites of obstruction for these children. In this review the authors address clinical indications for imaging, ideal team members to involve in an effective multidisciplinary program, basic anesthesia requirements, MRI protocol techniques and interpretation of the findings on MRI that help guide surgery.
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- 2018
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47. Assessment of pulmonary structure-function relationships in young children and adolescents with cystic fibrosis by multivolume proton-MRI and CT.
- Author
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Pennati F, Roach DJ, Clancy JP, Brody AS, Fleck RJ, Aliverti A, and Woods JC
- Subjects
- Adolescent, Biomarkers, Child, Child, Preschool, Disease Progression, Female, Functional Residual Capacity, Humans, Infant, Male, Protons, Respiration, Respiratory Function Tests, Retrospective Studies, Total Lung Capacity, Young Adult, Cystic Fibrosis diagnostic imaging, Lung diagnostic imaging, Magnetic Resonance Imaging, Tomography, X-Ray Computed
- Abstract
Background: Lung disease is the most frequent cause of morbidity and mortality in patients with cystic fibrosis (CF), and there is a shortage of sensitive biomarkers able to regionally monitor disease progression and to assess early responses to therapy., Purpose: To determine the feasibility of noncontrast-enhanced multivolume MRI, which assesses intensity changes between expiratory and inspiratory breath-hold images, to detect and quantify regional ventilation abnormalities in CF lung disease, with a focus on the structure-function relationship., Study Type: Retrospective., Population: Twenty-nine subjects, including healthy young children (n = 9, 7-37 months), healthy adolescents (n = 4, 14-22 years), young children with CF lung disease (n = 10, 7-47 months), and adolescents with CF lung disease (n = 6, 8-18 years) were studied., Field Strength/sequence: 3D spoiled gradient-recalled sequence at 1.5T., Assessment: Subjects were scanned during breath-hold at functional residual capacity (FRC) and total lung capacity (TLC) through noncontrast-enhanced MRI and CT. Expiratory-inspiratory differences in MR signal-intensity (Δ
1 H-MRI) and CT-density (ΔHU) were computed to estimate regional ventilation. MR and CT images were also evaluated using a CF-specific scoring system., Statistical Tests: Quadratic regression, Spearman's correlation, one-way analysis of variance (ANOVA)., Results: Δ1 H-MRI maps were sensitive to ventilation heterogeneity related to gravity dependence in healthy lung and to ventilation impairment in CF lung disease. A high correlation was found between MRI and CT ventilation maps (R2 = 0.79, P < 0.001). Globally, Δ1 H-MRI and ΔHU decrease with increasing morphological score (respectively, R2 = 0.56, P < 0.001 and R2 = 0.31, P < 0.001). Locally, Δ1 H-MRI was higher in healthy regions (median 15%) compared to regions with bronchiectasis, air trapping, consolidation, and to segments fed by airways with bronchial wall thickening (P < 0.001)., Data Conclusion: Multivolume noncontrast-enhanced MRI, as a nonionizing imaging modality that can be used on nearly any MRI scanner without specialized equipment or gaseous tracers, may be particularly valuable in CF care, providing a new imaging biomarker to detect early alterations in regional lung structure-function., Level of Evidence: 3 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:531-542., (© 2018 International Society for Magnetic Resonance in Medicine.)- Published
- 2018
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48. Pre- and post-operative visualization of neonatal esophageal atresia/tracheoesophageal fistula via magnetic resonance imaging.
- Author
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Higano NS, Bates AJ, Tkach JA, Fleck RJ, Lim FY, Woods JC, and Kingma PS
- Abstract
Esophageal atresia (EA) is a relatively uncommon congenital anomaly, often observed in conjunction with tracheoesophageal fistula (TEF). Surgical repair in neonates typically takes place with little information about the pre-existing EA/TEF structure because there are currently no acceptable tools for evaluating EA/TEF anatomy prior to repair; chest x-ray radiograph does not identify malformation sub-type or gap length, while x-ray computed tomography (CT) demonstrate an unacceptably high exposure to ionizing radiation. There is a need for safe imaging methods to evaluate pre-operative EA/TEF anatomy, which would add value in surgical planning; this need may be met with high-resolution structural MRI. We report three cases of Type-C EA/TEF in neonates. Patients were imaged prior to surgical repair using high-resolution ultrashort echo time (UTE) magnetic resonance imaging (MRI) to visualize tracheoesophageal anatomy and allow for informed surgical planning and risk management. One of the three patients was imaged post-repair to evaluate surgical efficacy and evolution of the tracheoesophageal anatomy.
- Published
- 2018
- Full Text
- View/download PDF
49. Reference Values for Central Airway Dimensions on CT Images of Children and Adolescents.
- Author
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Kuo W, Ciet P, Andrinopoulou ER, Chen Y, Pullens B, Garcia-Peña P, Fleck RJ, Paoletti M, McCartin M, Vermeulen F, Morana G, Lee EY, and Tiddens HAWM
- Subjects
- Adolescent, Age Factors, Child, Female, Humans, Male, Radiographic Image Interpretation, Computer-Assisted, Reference Values, Sex Factors, Young Adult, Bronchi diagnostic imaging, Tomography, X-Ray Computed methods, Trachea diagnostic imaging
- Abstract
Objective: The purpose of this study was to acquire normative data on central airway dimensions on chest CT scans in the pediatric population., Materials and Methods: Chest CT findings reported as normal by a radiologist were collected retrospectively at 10 international centers. An experienced and independent thoracic radiologist reevaluated all CT scans for image quality and for normal findings. Semiautomated image analysis was performed to measure dimensions of the trachea and right and left main bronchi at inspiration. Intrathoracic tracheal length was measured from carina to thorax inlet. Cross-sectional area and short and long axes were measured perpendicular to the longitudinal airway axis starting from the carina every centimeter upward for the trachea and every 0.5 cm downward for the main bronchi. The effects on airway diameters of age, sex, intrathoracic tracheal length, and distance from the carina were investigated by use of mixed-effects models analysis., Results: Among 1160 CT scans collected, 388 were evaluated as normal by the independent radiologist with sufficient image quality and adequate inspiratory volume level. Central airways were successfully semiautomatically analyzed in 294 of 388 CT studies. Age, sex, intrathoracic tracheal length, and distance from carina were all significant predictors in the models for tracheal and right and left main bronchial diameters (p < 0.001). The central airway dimensions increased with age up to 20 years, and dimensions were larger in male than in female adolescents., Conclusion: Normative data were determined for the central airways of children and adolescents. Central airway dimensions depended on distance from the carina and on intrathoracic tracheal length.
- Published
- 2018
- Full Text
- View/download PDF
50. Quantification of neonatal lung parenchymal density via ultrashort echo time MRI with comparison to CT.
- Author
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Higano NS, Fleck RJ, Spielberg DR, Walkup LL, Hahn AD, Thomen RP, Merhar SL, Kingma PS, Tkach JA, Fain SB, and Woods JC
- Subjects
- Female, Humans, Infant, Newborn, Lung anatomy & histology, Male, Prospective Studies, Reproducibility of Results, Sensitivity and Specificity, Image Interpretation, Computer-Assisted methods, Lung diagnostic imaging, Lung Diseases diagnostic imaging, Magnetic Resonance Imaging methods, Tomography, X-Ray Computed methods
- Abstract
Purpose: To demonstrate that ultrashort echo time (UTE) magnetic resonance imaging (MRI) can achieve computed tomography (CT)-like quantification of lung parenchyma in free-breathing, non-sedated neonates. Because infant CTs are used sparingly, parenchymal disease evaluation via UTE MRI has potential for translational impact., Materials and Methods: Two neonatal control cohorts without suspected pulmonary morbidities underwent either a research UTE MRI (n = 5; 1.5T) or a clinically-ordered CT (n = 9). Whole-lung means and anterior-posterior gradients of UTE-measured image intensity (arbitrary units, au, normalized to muscle) and CT-measured density (g/cm
3 ) were compared (Mann-Whitney U-test). Separately, a diseased neonatal cohort (n = 5) with various pulmonary morbidities underwent both UTE MRI and CT. UTE intensity and CT density were compared with Spearman correlations within ∼33 anatomically matched regions of interest (ROIs) in each diseased subject, spanning low- to high-density tissues. Radiological classifications were evaluated in all ROIs, with mean UTE intensities and CT densities compared in each classification., Results: In control subjects, whole-lung UTE intensities (0.51 ± 0.04 au) were similar to CT densities (0.44 ± 0.09 g/cm3 ) (P = 0.062), as were UTE (0.021 ± 0.020 au/cm) and CT (0.034 ± 0.024 [g/cm3 ]/cm) anterior-posterior gradients (P = 0.351). In diseased subjects' ROIs, significant correlations were observed between UTE and CT (P ≤0.007 in each case). Relative differences between UTE and CT were small in all classifications (4-25%)., Conclusion: These results demonstrate a strong association between UTE image intensity and CT density, both between whole-lung tissue in control patients and regional radiological pathologies in diseased patients. This indicates the potential for UTE MRI to longitudinally evaluate neonatal pulmonary disease and to provide visualization of pathologies similar to CT, without sedation/anesthesia or ionizing radiation., Level of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:992-1000., (© 2017 International Society for Magnetic Resonance in Medicine.)- Published
- 2017
- Full Text
- View/download PDF
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