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PIK3CA-related overgrowth spectrum (PROS) conditions of the head and neck are treatment challenges. Traditionally, these conditions require multiple invasive interventions, with incomplete malformation removal, disfigurement, and possible dysfunction. Use of the PI3K inhibitor alpelisib, previously shown to be effective in PROS, has not been reported in PIK3CA-associated head and neck lymphatic malformations (HNLMs) or facial infiltrating lipomatosis (FIL). We describe prospective treatment of 5 children with PIK3CA-associated HNLMs or head and neck FIL with alpelisib monotherapy.A total of 5 children with PIK3CA-associated HNLMs (n = 4) or FIL (n = 1) received alpelisib monotherapy (aged 2-12 years). Treatment response was determined by parental report, clinical evaluation, diary/questionnaire, and standardized clinical photography, measuring facial volume through 3-dimensional photos and magnetic resonance imaging.All participants had reduction in the size of lesion, and all had improvement or resolution of malformation inflammation/pain/bleeding. Common invasive therapy was avoided (ie, tracheotomy). After 6 or more months of alpelisib therapy, facial volume was reduced (range 1%-20%) and magnetic resonance imaging anomaly volume (range 0%-23%) were reduced, and there was improvement in swallowing, upper airway patency, and speech clarity.Individuals with head and neck PROS treated with alpelisib had decreased malformation size and locoregional overgrowth, improved function and symptoms, and fewer invasive procedures.

Rational and Objectives Ultrasound investigation of peripheral nerves, long used in the adult population, has been shown to be of value in diagnosing a variety of peripheral nerve abnormalities. More recently, nerve sonography has also been shown to be of use in pediatrics. However, normative values for nerve size in children have been lacking. As such, the goal of this research was to establish normative data for cross sectional area (CSA) measurements of the median and ulnar nerves in children. Materials and methods The median and ulnar nerves of 48 children ranging in age from 2 years to 17 years were imaged by ultrasound. CSA measurements were made at 2 separate sites for each nerve and measured independently by 6 pediatric radiologists. Reliability of ultrasound measurements between the radiologists was assessed by calculating intraclass correlation coefficients. Linear mixed-effects modeling was performed to develop prediction models for nerve cross sectional area for each nerve segment; 95% prediction values were generated from these models to approximate normal ranges. Results Agreement in nerve cross-sectional area measurements among the 6 radiologists for all nerve segments was good (ICC 0.82, 95% CI 0.78 to 0.85). CSA for both the median and ulnar nerves is larger in older children. However, statistical models to predict CSA using height perform better rather than those using a child's age. The range of normal nerve segment CSA using these prediction models based on child height are reported. Conclusion Median and ulnar nerve CSA can be reliably measured with ultrasound. Normal reference values for ulnar and median nerve CSA correlate with patient age but may be more optimally determined based on a child's height.

Background Medical trainees frequently note that cardiac anatomy is difficult to conceive within a two dimensional framework. The specific anatomic defects and the subsequent pathophysiology in flow dynamics may become more apparent when framed in three dimensional models. Given the evidence of improved comprehension using such modeling, this study aimed to contribute further to that understanding by comparing Virtual Reality (VR) and 3D printed models (3DP) in medical education. Objectives We sought to systematically compare the perceived subjective effectiveness of Virtual Reality (VR) and 3D printed models (3DP) in the educational experience of residents and nurse practitioners. Methods Trainees and practitioners underwent individual 15-minute teaching sessions in which features of a developmentally typical heart as well as a congenitally diseased heart were demonstrated using both Virtual Reality (VR) and 3D printed models (3DP). Participants then briefly explored each modality before filling out a short survey in which they identified which model (3DP or VR) they felt was more effective in enhancing their understanding of cardiac anatomy and associated pathophysiology. The survey included a binary summative assessment and a series of Likert scale questions addressing usefulness of each model type and degree of comfort with each modality. Results Twenty-seven pediatric residents and 3 nurse practitioners explored models of a developmentally typical heart and tetralogy of Fallot pathology. Most participants had minimal prior exposure to VR (1.1 ± 0.4) or 3D printed models (2.1 ± 1.5). Participants endorsed a greater degree of understanding with VR models (8.5 ± 1) compared with 3D Printed models (6.3 ± 1.8) or traditional models of instruction (5.5 ± 1.5) p Conclusions Our study shows that, overall, VR was preferred over 3DP models by pediatric residents and nurse practitioners for understanding cardiac anatomy and pathophysiology.

We sought to assess the feasibility of virtually assisted personalized tracheostomy tube (vapTT) implementation for patients with congenital airway anomalies (CAAs) and persistent tracheostomy tube (TT)-related respiratory failure at a tertiary pediatric hospital. Three patients (0-18 years) with CAAs and recurrent TT-related respiratory complications were managed with vapTT over 5 years. Patients underwent airway computed tomography acquisition with 3-dimensional reconstruction and TT virtual modeling for shape customization. Models were transferred to Bivona for fabrication based on industry-standard materials and processes. Clinical information and tracheoscopies assessing position, obstruction, and granulation were reviewed. Patients demonstrated resolution of visualized TT-related obstruction, granulation, or ulceration and de-escalation of respiratory support. Clinical events requiring urgent tracheoscopy decreased in all 3 patients. Sufficient relief of critical airway obstruction allowed progression of medical care and/or discharge. VapTTs are feasible for patients with CAA. This new frontier in personalized devices may serve uniquely challenging patient populations for whom standard treatments have failed.

Introduction Mid-life dietary patterns are associated with Alzheimer's disease (AD) risk, although few controlled trials have been conducted. Methods Eighty-seven participants (age range: 45 to 65) with normal cognition (NC, n = 56) or mild cognitive impairment (MCI, n = 31) received isocaloric diets high or low in saturated fat, glycemic index, and sodium (Western-like/West-diet vs. Mediterranean-like/Med-diet) for 4 weeks. Diet effects on cerebrospinal fluid (CSF) biomarkers, cognition, and cerebral perfusion were assessed to determine whether responses differed by cognitive status. Results CSF amyloid beta (Aβ)42/40 ratios increased following the Med-diet, and decreased after West-diet for NC adults, whereas the MCI group showed the reverse pattern. For the MCI group, the West-diet reduced and the Med-diet increased total tau (t-tau), whereas CSF Aβ42 /t-tau ratios increased following the West-diet and decreased following the Med-diet. For NC participants, the Med-diet increased and the West-diet decreased cerebral perfusion. Discussion Diet response during middle age may highlight early pathophysiological processes that increase AD risk.

OBJECTIVES: To evaluate the performance of 4-dimensional computed tomography (4D-CT) in assessing upper airway obstruction (UAO) in patients with Robin Sequence (RS) and compare the accuracy and reliability of 4D-CT and flexible fiberoptic laryngoscopy (FFL). STUDY DESIGN: Prospective survey of retrospective clinical data. SETTING: Single, tertiary care pediatric hospital. METHODS: At initial and 30-day timepoints, a multidisciplinary group of 11 clinicians who treat RS rated UAO severity in 36 sets of 4D-CT visualizations and FFL videos (dynamic modalities), and static CT images. Raters assessed UAO at the velopharynx and oropharynx (1-none to 5-complete) and noted confidence levels (LOC) of each rating. Intraclass correlation and Krippendorff’s Alpha were used to assess intra- and inter-rater reliability, respectively. Accuracy was assessed by comparing clinician ratings with Quantitative Percent Constriction (QPC) Ratings, calculated based on 4D-CT airway cross-sectional area. Results were compared using Wilcoxon rank-sum and signed-rank tests. RESULTS: 4D-CT and FFL demonstrated similar intra-rater agreement (moderate to substantial) and both demonstrated fair inter-rater agreement. Both modalities underestimated UAO severity, though 4D-CT ratings were significantly more accurate, as determined by QPC similarity, than FFL (−1.06 and −1.46 vs QPC Ratings, p=0.004). Overall LOC was similar for 4D-CT and FFL, but other specialists were significantly less confident in FFL ratings than were otolaryngologists (2.25 and 3.92, p

Background Facioscapulohumeral muscular dystrophy (FSHD) is a patchy and slowly progressive disease of skeletal muscle. MRI short tau inversion recovery (STIR) sequences of patient muscles often show increased hyperintensity that is hypothesized to be associated with inflammation. This is supported by the presence of inflammatory changes on biopsies of STIR-positive muscles. We hypothesized that the STIR positivity would normalize with targeted immunosuppressive therapy. Case presentation 45-year-old male with FSHD type 1 was treated with 12 weeks of immunosuppressive therapy, tacrolimus and prednisone. Tacrolimus was treated to a goal serum trough of > 5 ng/mL and prednisone was tapered every month. Quantitative strength exam, functional outcome measures, and muscle MRI were performed at baseline, week 6, and week 12. The patient reported subjective worsening as reflected in quantitative strength exam. The MRI STIR signal was slightly increased from 0.02 to 0.03 of total muscle; while the T1 fat fraction was stable. Functional outcome measures also were stable. Conclusions Immunosuppressive therapy in refractive autoimmune myopathy in other contexts has been shown to reverse STIR signal hyperintensity, however this treatment did not reverse STIR signal in this patient with FSHD. In fact, STIR signal slightly increased throughout the treatment period. This is the first study of using MRI STIR and T1 fat fraction to follow treatment effect in FSHD. We find that STIR might not be a dynamic marker for suppressing inflammation in FSHD.

Advances in understanding the pathophysiology of facioscapulohumeral dystrophy (FSHD) have led to the discovery of candidate therapeutics, and it is important to identify markers of disease activity to inform clinical trial design. For drugs that inhibit DUX4 expression, measuring DUX4 or DUX4-target gene expression might be an interim measure of drug activity; however, only a subset of FHSD muscle biopsies shows evidence of DUX4 expression. Our prior study showed that MRI T2-STIR-positive muscles had a higher probability of showing DUX4 expression than muscles with normal MRI characteristics. In the current study, we performed a 1-year follow-up assessment of the same muscle with repeat MRI and muscle biopsy. There was little change in MRI characteristics over the 1-year period and, similar to the initial evaluation, MRI T2-STIR-postive muscles had a higher expression of DUX4-regulated genes, as well as genes associated with inflammation, extracellular matrix and cell cycle. Compared to the initial evaluation, overall the level of expression in these gene categories remained stable over the 1-year period; however, there was some variability for each individual muscle biopsied. The pooled data from both the initial and 1-year follow-up evaluations identified several FSHD subgroups based on gene expression, as well as a set of genes—composed of DUX4-target genes, inflammatory and immune genes and cell cycle control genes—that distinguished all of the FSHD samples from the controls. These candidate markers of disease activity need to be replicated in independent datasets and, if validated, may provide useful measures of disease progression and response to therapy.

OBJECTIVE Assessing memory is often critical in surgical evaluation, although difficult to assess in young children and in patients with variable task abilities. While obtaining interpretable data from task-based functional MRI (fMRI) measures is common in compliant and awake patients, it is not known whether functional connectivity MRI (fcMRI) data show equivalent results. If this were the case, it would have substantial clinical and research generalizability. To evaluate this possibility, the authors evaluated the concordance between fMRI and fcMRI data collected in a presurgical epilepsy cohort. METHODS Task-based fMRI data for autobiographical memory tasks and resting-state fcMRI data were collected in patients with epilepsy evaluated at Seattle Children’s Hospital between 2010 and 2017. To assess memory-related activation and laterality, signal change in task-based measures was computed as a percentage of the average blood oxygen level–dependent signal over the defined regions of interest. An fcMRI data analysis was performed using 1000 Functional Connectomes Project scripts based on Analysis of Functional NeuroImages and FSL (Functional Magnetic Resonance Imaging of the Brain Software Library) software packages. Lateralization indices (LIs) were estimated for activation and connectivity measures. The concordance between these two measures was evaluated using correlation and regression analysis. RESULTS In this epilepsy cohort studied, the authors observed concordance between fMRI activation and fcMRI connectivity, with an LI regression coefficient of 0.470 (R2 = 0.221, p = 0.00076). CONCLUSIONS Previously published studies have demonstrated fMRI and fcMRI overlap between measures of vision, attention, and language. In the authors’ clinical sample, task-based measures of memory and analogous resting-state mapping were similarly linked in pattern and strength. These results support the use of fcMRI methods as a proxy for task-based memory performance in presurgical patients, perhaps including those who are more limited in their behavioral compliance. Future investigations to extend these results will be helpful to explore how the magnitudes of effect are associated with neuropsychological performance and postsurgical behavioral changes.

Objectives/hypothesis We hypothesized that the use of three-dimensional (3D) printed tracheal models to reproducibly simulate surgical technique variations in slide tracheoplasty would demonstrate the quantitative impact of surgical variables on postoperative tracheal dimensions. Study design Prospective analysis of three-dimensional printed surgical simulation models. Methods Slide tracheoplasty was performed on 3D printed long segment tracheal stenosis models with combinations of tracheal transection incision angle (90°, 45° beveled superior to inferior, 45° beveled inferior to superior) and tracheal transection location relative to the stenosis (at midpoint, 2 mm each superior and inferior to midpoint). Postoperative computed tomography (CT) scans measured changes in tracheal length, volume, and cross-sectional area compared to controls. Statistical analysis was performed using one-way analysis of variance and unpaired two-tailed t-tests. Results Slide tracheoplasty yielded 27 reconstructed tracheas. On average, slide tracheoplasty reduced total tracheal length by 36%. Beveled tracheal incisions yielded 9.5% longer final tracheas than straight transection incisions (P .05). Total tracheal luminal volume increased from 900 mm3 to 1378 mm3 overall and was largest with beveled incisions (P = .03). More material was discarded with straight incisions compared to beveled (89 mg vs. 19 mg, P Conclusions Beveled tracheal transection incisions resulted in increased tracheal length, longer anastomotic segments, increased volume, and reduced tissue waste as compared to straight incisions. Offsetting the incision from the midpoint of stenosis did not significantly affect reconstructed tracheal morphology. Using 3D printed models for surgical simulation can be helpful for the quantitative study of the effect isolated surgical variables on technical outcomes. Level of evidence 3 Laryngoscope, 2021.

Introduction: Preoperative functional MRI (fMRI) and intraoperative awake cortical mapping are established strategies to identify and preserve critical language structures during neurosurgery. There is growing appreciation for the need to similarly identify and preserve eloquent tissue critical for music production. Case Report: A 19-year-old female musician, with a 3- to 4-year history of events concerning for musicogenic seizures, was found to have a right posterior temporal tumor, concerning for a low-grade glial neoplasm. Preoperative fMRI assessing passive and active musical tasks localized areas of activation directly adjacent to the tumor margin. Cortical stimulation during various musical tasks did not identify eloquent tissue near the surgical site. A gross total tumor resection was achieved without disruption of singing ability. At 9-month follow-up, the patient continued to have preserved musical ability with full resolution of seizures and without evidence of residual lesion or recurrence. Conclusion: A novel strategy for performing an awake craniotomy, incorporating preoperative fMRI data for music processing with intraoperative cortical stimulation, interpreted with the assistance of a musician expert and facilitated gross total resection of the patient’s tumor without comprising her musical abilities.

Focal malformations of cortical development (FMCD) including focal cortical dysplasia (FCD), hemimegalencephaly (HMEG) and megalencephaly (MEG), constitute a spectrum of neurodevelopmental disorders associated with brain overgrowth, cellular and architectural dysplasia, intractable epilepsy, autism, and intellectual disability. Importantly, FCD is the most common cause of intractable pediatric focal epilepsy. Gain and loss of function mutations in the PI3K-AKT-MTOR pathway have been identified in this spectrum, with variable levels of mosaicism and tissue distribution. In this study, we aimed to assess droplet digital Polymerase Chain Reaction (ddPCR) as a first-tier molecular diagnostic method, as well as define genotype-phenotype relationships among the most common PI3K-AKT-MTOR pathway mutations in FMCD.A total of 144 specimens, including 113 brain samples, were collected from 58 individuals with intractable focal epilepsy phenotypes including FCD, MEG, HMEG and other types of developmental cortical lesions. We designed an ultra-deep and highly sensitive molecular diagnostic panel using ddPCR for six of the most common mutations in three PI3K-AKT-MTOR pathway genes, namelyPIK3CA(p.E542K, p.E545K, p.H1047R),AKT3(p.E17K) andMTOR(p.S2215F, p.S2215Y). We quantified the level of mosaicism across all samples and correlated genotypes with key phenotype, neuroimaging and neuropathological data.Pathogenic variants were identified in 17 individuals, with an overall molecular solve rate of %. Variant allele fractions (VAF) ranged from 0.1% to 22.67% across all positive samples. Our data shows thatMTORmutations are mostly associated with FCD, whereasPIK3CAmutations are more frequent in the HMEG-DMEG spectrum. The presence of one of these common PI3K-AKT-MTOR-mutations correlated with earlier onset of seizures. However, levels of mosaicism did not correlate with the severity of the cortical malformation by neuroimaging or neuropathological examination. Interestingly, we could not identify the six most common pathogenic variants in other types of cortical lesions (e.g., polymicrogyria or mesial temporal sclerosis) suggesting that PI3K-AKT-MTOR mutations are specifically causal in the FCD-HMEG-MEG spectrum. Finally, our data suggest that ultra-deep targeted molecular analysis for the most common PI3K-AKT-MTOR mutations via ddPCR is an effective molecular diagnostic approach for FMCD phenotypes with a good diagnostic yield when paired with neuroimaging and neuropathology evaluations. The high sensitivity and low DNA input requirements suggests that ddPCR is an effective molecular diagnostic tool for disorders caused by somatic mutations with a narrow mutational spectrum, including specific subtypes of pediatric epilepsy surgical phenotypes such as FCD and HMEG.

Thorough assessment of dynamic upper airway obstruction (UAO) in Robin sequence (RS) is critical, but traditional evaluation modalities have significant limitations. Four-dimensional computed tomography (4D-CT) is promising in that it enables objective and quantitative evaluation throughout all phases of respiration. However, there exist few protocols or analysis tools to assist in obtaining and interpreting the vast amounts of obtained data. A protocol and set of data analysis tools were developed to enable quantification and visualization of dynamic 4D-CT data. This methodology was applied to a sample case at 2 time points. In the patient with RS, overall increases in normalized airway caliber were observed from 5 weeks to 1 year. There was, however, continued dynamic obstruction at all airway levels, though objective measures of UAO did improve at the nasopharynx and oropharynx. Use of 4D-CT and novel analyses provide additional quantitative information to evaluate UAO in patients with RS.

Introduction Understanding congenital heart disease (CHD) is vital for medical personnel and parents of affected children. While traditional 2D schematics serve as the typical approach used, several studies have shown these models to be limiting in understanding complex structures. Recent world-emphasis has shifted to 3D printed models as a complement to 2D imaging to bridge knowledge and create new opportunities for experiential learning. We sought to systematically compare 3D digital and physical models for medical personnel and parent education compared to traditional methods. Methods 3D printed and digital models were made out of MRI and CT data for 20 common CHD. Fellows and nurse practitioners used these models to explore intra-cardiac pathologies following traditional teaching. The models were also used for parent education in outpatient settings after traditional education. The participants were then asked to fill out a Likert scale questionnaire to assess their understanding and satisfaction with different teaching techniques. These ratings were compared using paired t-tests and Pearson’s correlation. Results Twenty-five medical personnel (18 fellows; 2 nurses; 4 nurse practitioners and one attending) and twenty parents participated in the study. The diagnosis varied from simple mitral valve pathology to complex single ventricle palliation. Parent and medical personnel perceived understanding with digital models was significantly higher than traditional (p = 0.01). Subjects also felt that physical models were overall more useful than digital ones (p = 0.001). Physicians using models for parent education also perceived the models to be useful, not significantly impacting their clinical workflow. Conclusions 3D models, both digital and printed, enhance medical personnel and parental perceived understanding of CHD.

Cochlear implant depth of insertion affects audiologic outcomes and can be measured in adults using plain films obtained in the "cochlear view." The objective of this study was to assess interrater and intrarater reliability of measuring depth of insertion using cochlear view radiography.Prospective, observational.Tertiary referral pediatric hospital.Patients aged 11 months to 20 years (median, 4 years; interquartile range [IQR], 1-8 years) undergoing cochlear implantation at our institution were studied over 1 year. Children underwent cochlear view imaging on postoperative day 1. Films were deidentified and 1 image per ear was selected. Two cochlear implant surgeons and 2 radiologists evaluated each image and determined angular depth of insertion. Images were re-reviewed 6 weeks later by all raters. Inter- and intrarater reliability were calculated with intraclass correlation coefficients (ICCs).Fifty-seven ears were imaged from 42 children. Forty-nine ears (86%) had successful cochlear view x-rays. Median angular depth of insertion was 381° (minimum, 272°; maximum, 450°; IQR, 360°-395°) during the first round of measurement. Measurements of the same images reviewed 6 weeks later showed median depth of insertion of 382° (minimum, 272°; maximum, 449°; IQR, 360°-397°). Interrater and intrarater reliability ICCs ranged between 0.81 and 0.96, indicating excellent reliability.Postoperative cochlear view radiography is a reliable tool for measurement of cochlear implant depth of insertion in infants and children. Further studies are needed to determine reliability of intraoperatively obtained cochlear view radiographs in this population.

To investigate the gross white matter abnormalities in the structural brain MR imaging as well as white matter microstructural alterations using tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) in both affected and contralateral cerebral hemispheres of children with hemimegalencephaly (HMEG). From 2003 to 2019, we retrospectively reviewed brain MR images in 20 children (11 boys, 2 days–16.5 years) with HMEG, focusing on gross white matter abnormalities. DTI was evaluated in 12 patients (8 boys, 3 months–16.5 years) with HMEG and 12 age-, sex-, and magnetic field strength-matched control subjects. TBSS analysis was performed to analyze main white matter tracts. Regions of significant differences in fractional anisotropy (FA) were determined between HMEG and control subjects and between affected and contralateral hemispheres of HMEG. Gross white matter abnormalities were noted in both affected (n = 20, 100%) and contralateral hemisphere (n = 4, 20%) of HMEG. FA values were significantly decreased in both hemispheres of HMEG, compared with control subjects (P

Fibrodysplasia ossificans progressiva (FOP) is a rare disorder that causes heterotopic bone formation leading to chest wall and spinal deformities. This case describes an 11-year-old female with FOP who presented in respiratory failure necessitating two emergent fiberoptic nasotracheal intubations. The patient had severe trismus, rotary flexion of the neck, and distortion of the airway. A three-dimensional printed model based off of a computed tomography reconstruction was created for an in situ simulation before the true procedure. The surgery and trach change were both uneventful. We propose that with careful preoperative planning, tracheotomy can be an appropriate option for FOP patients. Laryngoscope, 129:812-817, 2019.

Facioscapulohumeral muscular dystrophy (FSHD) is a common, dominantly inherited disease caused by the epigenetic de-repression of the DUX4 gene, a transcription factor normally repressed in skeletal muscle. As targeted therapies are now possible in FSHD, a better understanding of the relationship between DUX4 activity, muscle pathology and muscle magnetic resonance imaging (MRI) changes is crucial both to understand disease mechanisms and for the design of future clinical trials. Here, we performed MRIs of the lower extremities in 36 individuals with FSHD, followed by needle muscle biopsies in safely accessible muscles. We examined the correlation between MRI characteristics, muscle pathology and expression of DUX4 target genes. Results show that the presence of elevated MRI short tau inversion recovery signal has substantial predictive value in identifying muscles with active disease as determined by histopathology and DUX4 target gene expression. In addition, DUX4 target gene expression was detected only in FSHD-affected muscles and not in control muscles. These results support the use of MRI to identify FSHD muscles most likely to have active disease and higher levels of DUX4 target gene expression and might be useful in early phase therapeutic trials to demonstrate target engagement in therapies aiming to suppress DUX4 expression.

BACKGROUND AND PURPOSE: The ketogenic diet, including both classic and modified forms, is an alternative to antiepileptic medications used in the treatment of drug-resistant epilepsy. We sought to evaluate the utility of proton MR spectroscopy for the detection of β-hydroxybutyrate in a cohort of children with epilepsy treated with the ketogenic diet and to correlate brain parenchymal metabolite ratios obtained from spectroscopy with β-hydroxybutyrate serum concentrations. MATERIALS AND METHODS: Twenty-three spectroscopic datasets acquired at a TE of 288 ms in children on the ketogenic diet were analyzed with LCModel using a modified basis set that included a simulated β-hydroxybutyrate resonance. Brain parenchymal metabolite ratios were calculated. Metabolite ratios were compared with serum β-hydroxybutyrate concentrations, and partial correlation coefficients were calculated using patient age as a covariate. RESULTS: β-hydroxybutyrate blood levels were highly correlated to brain β-hydroxybutyrate levels, referenced as either choline, creatine, or N -acetylaspartate. They were inversely but more weakly associated with N -acetylaspartate, regardless of the ratio denominator. No strong concordance with lactate was demonstrated. CONCLUSIONS: Clinical MR spectroscopy in pediatric patients on the ketogenic diet demonstrated measurable β-hydroxybutyrate, with a strong correlation to β-hydroxybutyrate blood levels. These findings may serve as an effective tool for noninvasive monitoring of ketosis in this population. An inverse correlation between serum β-hydroxybutyrate levels and brain tissue N -acetylaspartate suggests that altered amino acid handling contributes to the antiepileptogenic effect of the ketogenic diet.

Introduction MRI evaluation in facioscapulohumeral muscular dystrophy (FSHD) demonstrates fatty replacement and inflammation/edema in muscle. Our previous work demonstrated short T1 inversion recovery (STIR)-hyperintense (STIR+) signal in muscle 2 years before fatty replacement. We evaluated leg muscle STIR changes and fatty replacement within 14 months. Methods FSHD subjects received 2 MRI scans of thigh and calf over a 6.9- to 13.8-month interval. Quality of life measures were collected. One Radiologist rated muscle changes on a semi-quantitative scale. Results Fifteen subjects completed longitudinal imaging. Four STIR + muscles and 3 STIR-normal (STIR-) muscles were rated as progressing to fatty tissue over the study period. Discussion STIR + muscles with confluent regions of fat at baseline increased more in fat, while STIR- muscles had increases in septal-fat over the study period. These changes may reflect two phases of FSHD, demonstrating MRI sensitivity is weighted toward gross pathological phases of the disease. Muscle Nerve 57: 905-912, 2018.

Objective:To evaluate whether frontal-lobe magnetic resonance spectroscopy measures of γ-aminobutyric acid (GABA) would be altered in a sample of adolescents scanned after sport concussion because mild traumatic brain injury is often associated with working memory problems.Methods:Eleven adolescents (age 14–17 years) who had sustained a first-time sport concussion were studied with MRI/magnetic resonance spectroscopy within 23 to 44 days after injury (mean 30.4 ± 6.1 days). Age- and sex-matched healthy controls, being seen for sports-related injuries not involving the head and with no history of concussion, were also examined. GABA/creatine + phosphocreatine (Cre) was measured in left-sided frontal lobe and central posterior cingulate regions. The frontal voxel was positioned to overlap with patient-specific activation on a 1-back working memory task.Results:Increased GABA/Cre was shown in the frontal lobe for the concussed group. A decreased relationship was observed in the parietal region. High correlations between GABA/Cre and task activation were observed for the control group in the frontal lobe, a relationship not shown in the concussed participants.Conclusions:GABA/Cre appears increased in a region colocalized with working memory task activation after sport concussion. Further work extending these results in larger samples and at time points across the injury episode will aid in refining the clinical significance of these observations.

Introduction Electrical impedance myography (EIM) has been proposed as a noninvasive biomarker of muscle composition in facioscapulohumeral muscular dystrophy (FSHD). Here we determine the associations of EIM variables with muscle structure measured by MRI. Methods We evaluated 20 patients with FSHD at two centers, comparing EIM measurements (resistance, reactance, and phase at 50, 100, and 211 kHZ) recorded from bilateral vastus lateralis, tibialis anterior, and medial gastrocnemius muscles to MRI skin and subcutaneous fat thickness, MRI T1-based muscle severity score (T1 muscle score), and MRI quantitative intramuscular Dixon fat fraction (FF). Results While reactance and phase both correlated with FF and T1 muscle score, 50 kHz reactance was most sensitive to muscle structure alterations measured by both T1 score (rho = -0.71, P < .001) and FF (rho = -0.74, P < .001). Discussion This study establishes the correlation of EIM with structural MRI features in FSHD and supports further evaluation of EIM as a potential biomarker in FSHD clinical trials.

INTRODUCTION Indications for TIPS are well described in adults and involve complications of PHTN. Complications from PHTN are associated with PSG of > 12 mm Hg in adults. It is unclear if these parameters apply to children with PHTN. OBJECTIVE To assess whether adult criteria for TIPS placement can be utilized in children, describe laboratory changes over time, and report outcomes. METHODS We performed a retrospective review of 34 pediatric patients who underwent TIPS, examining indications, radiology, PSG reductions, laboratory changes, and outcomes. RESULTS Most patients had PHTN due to parenchymal liver disease including congenital hepatic fibrosis (n = 5), biliary atresia (n = 5), cystic fibrosis-related liver disease (n = 3) and cavernous transformation of the portal vein (n = 6). Indications for TIPS included variceal bleeding, recurrent ascites, and maintenance of portal vein flow following thrombolysis. Variceal bleeding was observed in six children with PSG

IMPORTANCE: There is no imaging standard to model nasal cartilage for the planning of rhinoplasty procedures. Preoperative visualization of cartilage may improve objective evaluation of nasal deformities, surgical planning, and surgical reconstruction. OBJECTIVES: To evaluate the feasibility of visualizing nasal cartilage using high resolution micro–computed tomography (CT) compared with the criterion standard of pathologic findings in a cadaveric specimen and to evaluate its accuracy compared with various clinical CT protocols. DESIGN, SETTING, AND PARTICIPANTS: Anatomic study at the University of Washington using single human cadaveric nasal specimens performed from July 10, 2017, to March 30, 2018. INTERVENTIONS: A micro-CT acquisition with 60-micron resolution was obtained of a nasal specimen. The specimen was then scanned with 5 different clinical CT protocols to span both clinical care and machine limits. The specimen was then sectioned in 5-mm axial slices for pathologic analysis. MAIN OUTCOMES AND MEASURES: Micro-CT images were registered to pathologic specimen cross-sections using a graphite fiducial system. Cartilage substructures were manually segmented and analyzed. A library of matched images across the micro-CT and various clinical CT protocols was then developed. Region of interest analysis was performed for each of the cartilage structures and their boundaries on clinical CT protocols and micro-CT, with the outcome of mean (SD) density using Hounsfield units. RESULTS: A single human cadaveric nasal specimen was used to obtain the following results. Lower lateral cartilage, upper lateral cartilage, and septal cartilage were accurately delineated on the micro-CT images compared with pathologic findings. The mean absolute deviation from pathologic findings was 0.30 mm for septal cartilage thickness, 0.98 mm for maximal upper lateral cartilage length, and 1.40 mm for maximal lower lateral cartilage length. On clinical CT protocols, only septal cartilage was well discriminated from boundary. Higher radiation dose resulted in more accurate density measurements of cartilage, but it did not ultimately improve ability to discriminate cartilage. CONCLUSIONS AND RELEVANCE: The results of this anatomic study may represent a notable step toward advancing knowledge of the capabilities and pitfalls of nasal cartilage visualization on CT. Nasal cartilage visualization was feasible on the micro-CT compared with pathologic findings. Future research may further examine the barriers to accurately visualizing upper lateral cartilage and lower lateral cartilage, a prerequisite for clinical application. LEVEL OF EVIDENCE: NA.

Limited documentation exists about how frequently radiologically visible rebleeding occurs with abusive subdural hemorrhages (SDH). Likewise, little is known about rebleeding predispositions and associated symptoms. To describe the frequency of subdural rebleeding after abusive head trauma (AHT), its predispositions and clinical presentation. We evaluated children with SDHs from AHT who were reimaged within a year of their initial hospitalization, retrospectively reviewing clinical details and imaging. We used the available CT and MR images. We then performed simple descriptive and comparative statistics. Fifty-four of 85 reimaged children (63.5%) with AHT-SDH rebled. No child had new trauma, radiologic evidence of new parenchymal injury or acute neurologic symptoms from rebleeding. From the initial presentation, macrocephaly was associated with subsequent rebleeding. Greater subdural depth, macrocephaly, ventriculomegaly and brain atrophy at follow-up were associated with rebleeding. No other radiologic findings at initial presentation or follow-up predicted rebleeding risk, although pre-existing brain atrophy at initial admission and initial chronic SDHs barely missed significance. Impact injuries, retinal hemorrhages and clinical indices of initial injury severity were not associated with rebleeding. All rebleeding occurred within chronic SDHs; no new bridging vein rupture was identified. The mean time until rebleeding was recognized was 12 weeks; no child had rebleeding after 49 weeks. Subdural rebleeding is common and occurs in children who have brain atrophy, ventriculomegaly, macrocephaly and deep SDHs at rebleed. It usually occurs in the early months post-injury. All children with rebleeds were neurologically asymptomatic and lacked histories or clinical or radiologic findings of new trauma. Bleeds did not occur outside of chronic SDHs. We estimate the maximum predicted frequency of non-traumatic SDH rebleeding accompanied by acute neurological symptoms in children with a prior abusive SDH is 3.5%.

Measuring the severity and progression of facioscapulohumeral muscular dystrophy (FSHD) is particularly challenging because muscle weakness progresses over long periods of time and can be sporadic. Biomarkers are essential for measuring disease burden and testing treatment strategies. We utilized the sensitive, specific, high-throughput SomaLogic proteomics platform of 1129 proteins to identify proteins with levels that correlate with FSHD severity in a cross-sectional study of two independent cohorts. We discovered biomarkers that correlate with clinical severity and disease burden measured by magnetic resonance imaging. Sixty-eight proteins in the Rochester cohort (n = 48) and 51 proteins in the Seattle cohort (n = 30) had significantly different levels in FSHD-affected individuals when compared with controls (p-value ≤ .005). A subset of these varied by at least 1.5 fold and four biomarkers were significantly elevated in both cohorts. Levels of creatine kinase MM and MB isoforms, carbonic anhydrase III, and troponin I type 2 reliably predicted the disease state and correlated with disease severity. Other novel biomarkers were also discovered that may reveal mechanisms of disease pathology. Assessing the levels of these biomarkers during clinical trials may add significance to other measures of quantifying disease progression or regression.

Concussion is a known risk in youth soccer, but little is known about subconcussive head impacts. The authors provided a prospective cohort study measuring frequency and magnitude of subconcussive head impacts using accelerometry in a middle school–age soccer tournament, and association between head impacts and changes in (1) symptoms, (2) cognitive testing, and (3) advanced neuroimaging. A total of 17 youth completed the study (41% female, mean 12.6 years). There were 73 head impacts >15 g measured (45% headers) and only 2 had a maximum peak linear acceleration >50 g. No youth reported symptoms consistent with concussion. After correction for multiple comparisons and a sensitivity analysis excluding clear outliers, no significant associations were found between head impact exposure and neuropsychological testing or advanced neuroimaging. The authors conclude that head impacts were relatively uncommon and low in acceleration in youth playing a weekend soccer tournament. This study adds to the limited data regarding head impacts in youth soccer.

Posterior fossa syndrome is a severe transient loss of language that frequently complicates resection of tumors of the cerebellum. The associated pathophysiology and relevant anatomy to this language deficit remains controversial. We performed a retrospective analysis of all cerebellar tumor resections at Seattle Children's Hospital from 2010 to 2015. Diffusion tensor imaging was performed on each of the patients as part of their clinical scan. Patients included in the study were divided into groups based on language functioning following resection: intact (N = 19), mild deficit (N = 19), and posterior fossa syndrome (N = 9). Patients with posterior fossa syndrome showed white matter changes evidenced by reductions in fractional anisotropy in the left and right superior cerebellar peduncle following resection, and these changes were still evident 1-year after surgery. These changes were greater in the superior cerebellar peduncle than elsewhere in the cerebellum. Prior to surgery, posterior fossa patients did not show changes in fractional anisotropy however differences were observed in mean and radial diffusivity measures in comparison to other groups which may provide a radiographic marker of those at greatest risk of developing post-operative language loss., Highlights • Language deficit associated with posterior fossa syndrome (PFS) remains controversial. • Diffusion tensor imaging of PFS was analyzed pre-op, post-op and 1-year post resection. • PFS patients show white matter change in the superior cerebellar peduncles. • No white matter change was observed prior to surgery. • Findings were evident post-op and remained at 1 year follow up.

The original article included a statement which is not fully accurate. This correction clarifies the original statement.

Objective To evaluate whether quantitative metrics of white matter fractional anisotropy (FA) and mean diffusivity (MD) were different in patients presenting to our clinic with persistent symptoms after a concussion. Design Matched control retrospective study. Setting Primary not-for-profit Institution. Patients Consecutive patients seen at a primary care institution's Sports Concussion Clinic for sport-related concussion that underwent diffusion tensor imaging. Interventions (Independent variables): Type of sports, days from Injury, number of symptoms, weeks out when Magnetic Resonance Imaging (MRI) ordered, history of psychological issues, length of symptoms, age, sex, MRI imaging data. Main outcome measure Difference in white matter FA and MD. Results Seventeen concussion patients, ages 9 and 17 (average = 12.5 years; median = 13 years, 11 males and 6 females), were matched with age and gender controls who had an MRI following a complaint of headache. Patients reported an average of 11.5 concussion symptoms, out of a total possible 22 and were seen at an average of 30 days post injury. No region met tract based spatial statistics criteria for significant differences between concussed and healthy control groups (all p > 0.05). Similarly, when comparing group averages from the atlas based regional summaries, no region met the 0.2 false discovery rate (FDR) threshold for significant differences (the smallest unadjusted p-values were 0.02 for MD and 0.14 for FA). Conclusions Our results did not show measurable diffusion tensor imaging (DTI) changes with standard clinical data acquisition and quantitative processing for the individual patient. At this time DTI should not be considered a technique that can diagnose concussion within an individual subject.

OBJECTIVE Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease. An inexpensive and rapid imaging tool, infrared thermal imaging, was evaluated for its utility to detect active bone lesions in extremities of children with CNO. METHODS Children with suspected active CNO and healthy controls were enrolled. All subjects underwent infrared thermal imaging of the lower extremities. Patients in the CNO group also received a magnetic resonance imaging (MRI) examination. Hyperintensity within bone marrow on a fluid-sensitive T2-weighted MRI sequence was considered confirmatory for inflammation. Infrared thermal data were analyzed using custom software by dividing the leg below the knee into 3 equal segments longitudinally and adding the distal femur segment as an equal length above the knee. Median and 95th percentile temperatures were recorded for each leg segment. Temperature differences between inflamed and uninflamed segments in all subjects (both intersubject and intrasubject) were evaluated using a linear mixed-effects model. RESULTS Thirty children in the suspected/known CNO group and 31 healthy children were enrolled. In the healthy control group, males had significantly higher temperature in their lower extremities than females (P < 0.05). There was no difference in temperature detected between inflamed leg segments of patients with CNO versus uninflamed leg segments of the healthy control group. However, within the CNO group, significantly higher temperatures were detected for inflamed versus uninflamed distal tibia/fibula segments (P < 0.01). CONCLUSION Children with active CNO lesions in the distal tibia/fibula exhibited higher regional temperatures on average than healthy extremities. Larger studies are warranted to further evaluate the clinical utility of infrared thermal imaging for CNO detection.

Background In this observational study, white matter structure, functional magnetic resonance imaging (fMRI) task-based responses, and functional connectivity were assessed in four subjects with high functioning pyridoxine-dependent epilepsy and age-matched control subjects. Methods Four male subjects with pyridoxine-dependent epilepsy (mean age 31 years 8 months, standard deviation 12 years 3 months) and age-matched control subjects (32 years 4 months, standard deviation 13 years) were recruited to participate in the study. Diffusion tensor data were collected and postprocessed in Functional Magnetic Resonance Imaging of the Brain Software Library to quantify corpus callosum tracts as a means to assess white matter structure. Task-based fMRI data were collected and Functional Magnetic Resonance Imaging of the Brain Software Library used to assess task response. The fMRI resting-state data were analyzed with the functional connectivity toolbox Conn to determine functional connectivity. Results Subjects with high functioning pyridoxine-dependent epilepsy retained structural white matter connectivity compared with control subjects, despite morphologic differences in the posterior corpus callosum. fMRI task-based results did not differ between subjects with pyridoxine-dependent epilepsy and control subjects; functional connectivity as measured with resting-state fMRI was lower in subjects with pyridoxine-dependent epilepsy for several systems (memory, somatosensory, auditory). Conclusion Although corpus callosum morphology is diminished in the posterior portions, structural connectivity was retained in subjects with pyridoxine-dependent epilepsy, while functional connectivity was diminished for memory, somatosensory, and auditory systems.

STUDY DESIGN Retrospective dose-simulation comparison. OBJECTIVE To determine if sufficient detail for preoperative analysis of bony anatomy can be acquired at substantially lower doses than those typically used. SUMMARY OF BACKGROUND DATA Computed tomography (CT) is a preoperative planning tool for spinal surgery. The pediatric population is at risk to express the harmful effects of ionizing radiation. Preoperative CT scans are presently performed at standard pediatric radiation doses not tailored for surgical planning. METHODS We used the validated GE Noise Injection software to retrospectively modify existing spine and chest CT scans from 10 patients to create CT images that simulated a standard dose (100%), 50% dose, and 25% dose scans. 4 orthopedic surgeons and a pediatric radiologist, blinded to dose, measured minimum medial-lateral pedicle width and maximum anterior-posterior bony length along the axis of presumed pedicle screw placement. A total of 90 axial images were generated to create our sample set. Measurements were evaluated for accuracy, precision, and consistency. RESULTS For any given rater, there was no clinically relevant difference between measurements at the different dose levels and no apparent degradation in precision at the different dose levels. Consistent variation was observed between raters, the likely result of individual differences in measurement approach. CONCLUSION Spinal CT scans done for preoperative planning can be performed at 25% of current radiation doses without a loss in surgical planning measurement accuracy or precision. These 25% dose-reduced scans would have average Computed Tomography Dose Index volume dose levels of roughly 1.0 to 2.5 mGy (depending on patient size) and size-specific dose estimates of roughly 2.5 mGy representing a substantial dose savings compared to current practice for many sites. Standardization of consistent landmarks may be useful to further improve inter-rater concordance.

OBJECTIVEFunctional connectivity magnetic resonance imaging (fcMRI) is a form of fMRI that allows for analysis of blood oxygen level–dependent signal changes within a task-free, resting paradigm. This technique has been shown to have efficacy in evaluating network connectivity changes with epilepsy. Presurgical data from patients with unilateral temporal lobe epilepsy were evaluated using the fcMRI technique to define connectivity changes within and between the diseased and healthy temporal lobes using a within-subjects design.METHODSUsing presurgical fcMRI data from pediatric patients with unilateral temporal lobe epilepsy, the authors performed seed-based analyses within the diseased and healthy temporal lobes. Connectivity within and between temporal lobe seeds was measured and compared.RESULTSIn the cohort studied, local ipsilateral temporal lobe connectivity was significantly increased on the diseased side compared to the healthy temporal lobe. Connectivity of the diseased side to the healthy side, on the other hand, was significantly reduced when compared to connectivity of the healthy side to the diseased temporal lobe. A statistically significant regression was observed when comparing the changes in local ipsilateral temporal lobe connectivity to the changes in inter–temporal lobe connectivity. A statistically significant difference was also noted in ipsilateral connectivity changes between patients with and those without mesial temporal sclerosis.CONCLUSIONSUsing fcMRI, significant changes in ipsilateral temporal lobe and inter–temporal lobe connectivity can be appreciated in unilateral temporal lobe epilepsy. Furthermore, fcMRI may have a role in the presurgical evaluation of patients with intractable temporal lobe epilepsy.

ObjectiveTo evaluate the features and maturational changes in overall callosal shape in patients with pyridoxine-dependent epilepsy (PDE).MethodsMeasurements were conducted through landmark-based geometric morphometrics applied on cerebral MRIs of patients with PDE and age-matched control subjects. The outline of the corpus callosum was manually traced in the midsagittal plane. Three hundred semi-landmarks along the outline were collected and underwent statistical generalized Procrustes analysis. An allometric regression was applied to evaluate the callosal shape due to growth over time.ResultsThirty-eight patients with PDE and 38 age- and sex-matched control subjects were included. Mean age at the time of the MRI in the patient group was 9.3 years (median 6.3 years, range 0.01–48 years). Significant differences (p< 0.01) in the mean callosal shape between patients and controls were found. The allometric regression model revealed significant shape variations (p< 0.01) between the 2 study groups across the developmental course after controlling for the effect of callosal size on shape. This latter effect turned out to be significant as well (p< 0.001).ConclusionsPatients with PDE show an altered callosal shape and variations in callosal ontogeny, which are likely secondary to the underlying genetic defect with abnormal function of antiquitin, the product of theALDH7A1gene.

A subset of patients experience persistent symptoms after pediatric concussion, and magnetic resonance imaging (MRI) is commonly used to evaluate for pathology. The utility of this practice is unclear. We conducted a retrospective cohort study to describe the MRI findings in children with concussion. A registry of all patients seen at our institution from January 2010 through March 2016 with pediatric sports-related concussion was cross-referenced with a database of radiographical studies. Radiology reports were reviewed for abnormal findings. Patients with abnormal computed tomographies or MRI scans ordered for reasons other than concussion were excluded. Among 3338 children identified with concussion, 427 underwent MRI. Only 2 (0.5%) had findings compatible with traumatic injury, consisting in both of microhemorrhage. Sixty-one patients (14.3%) had abnormal findings unrelated to trauma, including 24 nonspecific T2 changes, 15 pineal cysts, eight Chiari I malformations, and five arachnoid cysts. One child underwent craniotomy for a cerebellar hemangioblastoma after presenting with ataxia; another had cortical dysplasia resected after seizure. The 2 patients with microhemorrhage each had three previous concussions, significantly more than patients whose scans were normal (median, 1) or abnormal without injury (median, 1.5; p = 0.048). MRI rarely revealed intracranial injuries in children post-concussion, and the clinical relevance of these uncommon findings remains unclear. Abnormalities unrelated to trauma are usually benign. However, MRI should be thoughtfully considered in children who present with concerning or atypical symptoms.

Author(s): Craft, Suzanne; Claxton, Amy; Baker, Laura D; Hanson, Angela J; Cholerton, Brenna; Trittschuh, Emily H; Dahl, Deborah; Caulder, Erin; Neth, Bryan; Montine, Thomas J; Jung, Youngkyoo; Maldjian, Joseph; Whitlow, Christopher; Friedman, Seth | Abstract: BackgroundLong acting insulin detemir administered intranasally for three weeks enhanced memory for adults with Alzheimer's disease dementia (AD) or amnestic mild cognitive impairment (MCI). The investigation of longer-term administration is necessary to determine whether benefits persist, whether they are similar to benefits provided by regular insulin, and whether either form of insulin therapy affects AD biomarkers.ObjectiveThe present study aimed to determine whether four months of treatment with intranasal insulin detemir or regular insulin improves cognition, daily functioning, and AD biomarkers for adults with MCI or AD.MethodsThis randomized, double-blind, placebo-controlled trial included an intent-to-treat sample consisting of 36 adults diagnosed with MCI or mild to moderate AD. Participants received placebo (n = 12), 40 IU of insulin detemir (n = 12), or 40 IU of regular insulin (n = 12) daily for four months, administered with a nasal delivery device. A cognitive battery was administered at baseline and after two and four months of treatment. MRI was administered for all participants and lumbar puncture for a subset (n = 20) at baseline and four months. The primary outcome was change from baseline to four months on a memory composite (sum of Z scores for delayed list and story recall). Secondary outcomes included: global cognition (Alzheimer's Disease Assessment Scale-Cognition), daily functioning (Dementia Severity Rating Scale), MRI volume changes in AD-related regions of interest, and cerebrospinal fluid AD markers.ResultsThe regular insulin treated group had better memory after two and four months compared with placebo (p l 0.03). No significant effects were observed for the detemir-assigned group compared with the placebo group, or for daily functioning for either group. Regular insulin treatment was associated with preserved volume on MRI. Regular insulin treatment was also associated with reduction in the tau-P181/Aβ42 ratio.ConclusionFuture research is warranted to examine the mechanistic basis of treatment differences, and to further assess the efficacy and safety of intranasal insulin.

Introduction: Magnetic resonance imaging of muscle shows short tau-inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker. Methods: Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes. Results: In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams. Conclusions: Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2-year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored. Muscle Nerve 49: 257–260, 2014

Nasoduodenal tube (NDT) placement is typically performed at the bedside and two-view abdominal radiographs are usually used to confirm tube position. Anecdotally, in most instances the lateral view is unnecessary and utilizes more than twice the radiation than an anteroposterior (AP) view alone. We hypothesize that NDT location can be determined using only the AP view, with the NDT position determined on two views utilized as the gold standard. A search was performed for all two- or three-view abdominal radiographs from September 2012 to September 2013 with the phrase “ND tube” in the reason field of the requisition. These studies were independently reviewed by two radiologists and scored for anatomical tube position in three different scenarios: AP view alone, the lateral view alone, and both views together, with the latter serving as the gold standard. The anatomical scores were subsequently grouped to reflect clinically significant scenarios. Comparative analysis was performed with the original and clinically grouped scores. A total of 102 patients and 306 separate two-view exams were evaluated. Of the 102 patients, 55 had at least two separate exams. Across raters, concordances of AP and lateral scores relative to the gold standard assessment were 88% and 73% for anatomical scores, and 91.5% and 86.4% for clinically grouped data. Trend differences for fewer errors were found with the AP compared to the lateral view. There were statistically significant group differences with a greater number of false-negative errors in the lateral data set. No clear differences were found when comparing AP and lateral ratings for false-positive errors. Upon review of the common errors, we determined a few imaging findings on AP radiographs that can help assess the need for an additional lateral view. A single AP view is sufficient to determine the NDT position in most cases. Two views should be reserved for cases where the NDT position cannot be definitively assessed. Transitioning toward the single AP view to evaluate the NDT position could have immediate consequences for dose reduction.

Purpose To compare the derived T2* values and reproducibility of three methods used to assess iron-loading in heart and liver. Materials and Methods In 23 pediatric patients, liver and cardiac gradient-echo imaging datasets (within-exam repeated sequence pairs) were evaluated. Data analyses compared derived relaxation values (average of pairs) and coefficient of variation (reproducibility of pairs). Results T2* values showed differences across methods, with pixel-wise mean > average fit > pixel-wise median. Coefficient of variation was found to be lower (better) with pixel-wise median and average fit methods compared to the pixel-wise mean technique. Maximum coefficient of variation values were lowest for the pixel-wise median approach in both the heart and liver. Conclusion Differences in derived T2* values between methods must be considered when comparing values to established magnetic resonance imaging (MRI)-biopsy formulas. The pixel-wise median and average fit methods demonstrate substantial benefits in reproducibility compared to the pixel-wise mean method. Since minimal variation in measurement is critical for patient care, median processing of relaxometry data may be preferable in both tissue types. J. Magn. Reson. Imaging 2013;38:987–990. © 2012 Wiley Periodicals, Inc.