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A complex of interrelated methods and means of analysis, clustering, segmentation and classification of objects on images obtained by sensors of different physical nature (with the help of modern methods of radiography, computer and magnetic resonance imaging) is proposed, which will allow modeling the optimal form of a bone substitute with functional properties by CAD/CAM/CAE design methods, depending on the anatomical data, the nature and localization of the cavity bone defect, its size, load conditions and patterns of bone tissue neoplasm. Methods for making multi-criteria decisions have been developed, which will allow for their implementation for a wide range of optimization tasks of researching the correlation of the shape and size of porosity with indicators of the stress-deformed state of bone substitutes in order to maintain the structural integrity of the biomaterial in the process of regeneration of hard tissue. [ABSTRACT FROM AUTHOR]

To evaluate the image quality of low-dose CT colonography (CTC) using deep learning-based reconstruction (DLR) compared to iterative reconstruction (IR). Adults included in the study were divided into four groups according to body mass index (BMI). Routine-dose (RD: 120 kVp) CTC images were reconstructed with IR (RD-IR); low-dose (LD: 100 kVp) images were reconstructed with IR (LD-IR) and DLR (LD-DLR). The subjective image quality was rated on a 5-point scale by two radiologists independently. The parameters for objective image quality included noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The Friedman test was used to compare the image quality among RD-IR, LD-IR and LD-DLR. The Kruskal Wallis test was used to compare the results among different BMI groups. A total of 270 volunteers (mean age: 47.94 years ± 11.57; 115 men) were included. The effective dose of low-dose CTC was decreased by approximately 83.18% (5.18 mSv ± 0.86 vs. 0.86 mSv ± 0.05, P < 0.001). The subjective image quality score of LD-DLR was superior to that of LD-IR (3.61 ± 0.56 vs. 2.70 ± 0.51, P < 0.001) and on par with the RD- IR's (3.61 ± 0.56 vs. 3.74 ± 0.52, P = 0.486). LD-DLR exhibited the lowest noise, and the maximum SNR and CNR compared to RD-IR and LD-IR (all P < 0.001). No statistical difference was found in the noise of LD-DLR images between different BMI groups (all P > 0.05). Compared to IR, DLR provided low-dose CTC with superior image quality at an average radiation dose of 0.86 mSv, which may be promising in future colorectal cancer screening. [ABSTRACT FROM AUTHOR]

Introduction: Mild stenosis [degree of stenosis (DS) < 50%] is commonly labeled as nonobstructive lesion. Some lesions remain stable for several years, while others precipitate acute coronary syndromes (ACS) rapidly. The causes of ACS and the factors leading to diverse clinical outcomes remain unclear.Method: This study aimed to investigate the hemodynamic influence of mild stenosis morphologies in different coronary arteries. The stenoses were modeled with different morphologies based on a healthy individual data. Computational fluid dynamics analysis was used to obtain hemodynamic characteristics, including flow waveforms, fractional flow reserve (FFR), flow streamlines, time-average wall shear stress (TAWSS), and oscillatory shear index (OSI).Results: Numerical simulation indicated significant hemodynamic differences among different DS and locations. In the 20%–30% range, significant large, low-velocity vortexes resulted in low TAWSS (40 dyne/cm2), rapidly expanding the high TAWSS area (averagely increased by 0.46 cm2) in left main artery and left anterior descending artery (LAD), where high OSI areas remained extensive (>0.19 cm2).Discussion: While mild stenosis does not pose any immediate ischemic risk due to a FFR > 0.95, 20%–50% stenosis requires attention and further subdivision based on location is essential. Rapid progression is a danger for lesions with 20%–30% DS near the stenoses and in the proximal LAD, while lesions with 30%–50% DS can cause plaque injury and rupture. These findings support clinical practice in early assessment, monitoring, and preventive treatment.

Abstract The study aims to develop a deep learning based automatic segmentation approach using the UNETR(U-net Transformer) architecture to quantify the volume of individual thigh muscles(27 muscles in 5 groups) for Sarcopenia assessment. By automating the segmentation process, this approach improves the efficiency and accuracy of muscle volume calculation, facilitating a comprehensive understanding of muscle composition and its relationship to Sarcopenia. The study utilized a dataset of 72 whole thigh CT scans from hip fracture patients, annotated by two radiologists. The UNETR model was trained to perform precise voxel-level segmentation and various metrics such as dice score, average symmetric surface distance, volume correlation, relative absolute volume difference and Hausdorff distance were employed to evaluate the model’s performance. Additionally, the correlation between Sarcopenia and individual thigh muscle volumes was examined. The proposed model demonstrated superior segmentation performance compared to the baseline model, achieving higher dice scores (DC = 0.84) and lower average symmetric surface distances (ASSD = 1.4191 ± 0.91). The volume correlation between Sarcopenia and individual thigh muscles in the male group. Furthermore, the correlation analysis of grouped thigh muscles also showed negative associations with Sarcopenia in the male participants. This thesis presents a deep learning based automatic segmentation approach for quantifying individual thigh muscle volume in sarcopenia assessment. The results highlights the associations between Sarcopenia and specific individual muscles as well as grouped thigh muscle regions, particularly in males. The proposed method improves the efficiency and accuracy of muscle volume calculation, contributing to a comprehensive evaluation of Sarcopenia. This research enhances our understanding of muscle composition and performance, providing valuable insights for effective interventions in Sarcopenia management.

The study aims to develop a deep learning based automatic segmentation approach using the UNETR(U-net Transformer) architecture to quantify the volume of individual thigh muscles(27 muscles in 5 groups) for Sarcopenia assessment. By automating the segmentation process, this approach improves the efficiency and accuracy of muscle volume calculation, facilitating a comprehensive understanding of muscle composition and its relationship to Sarcopenia. The study utilized a dataset of 72 whole thigh CT scans from hip fracture patients, annotated by two radiologists. The UNETR model was trained to perform precise voxel-level segmentation and various metrics such as dice score, average symmetric surface distance, volume correlation, relative absolute volume difference and Hausdorff distance were employed to evaluate the model’s performance. Additionally, the correlation between Sarcopenia and individual thigh muscle volumes was examined. The proposed model demonstrated superior segmentation performance compared to the baseline model, achieving higher dice scores (DC = 0.84) and lower average symmetric surface distances (ASSD = 1.4191 ± 0.91). The volume correlation between Sarcopenia and individual thigh muscles in the male group. Furthermore, the correlation analysis of grouped thigh muscles also showed negative associations with Sarcopenia in the male participants. This thesis presents a deep learning based automatic segmentation approach for quantifying individual thigh muscle volume in sarcopenia assessment. The results highlights the associations between Sarcopenia and specific individual muscles as well as grouped thigh muscle regions, particularly in males. The proposed method improves the efficiency and accuracy of muscle volume calculation, contributing to a comprehensive evaluation of Sarcopenia. This research enhances our understanding of muscle composition and performance, providing valuable insights for effective interventions in Sarcopenia management. [ABSTRACT FROM AUTHOR]

Colon cancer is the third most common malignancy in Canada. Computed tomography colonography (CTC) provides a creditable and validated option for colon screening and assessment of known pathology in patients for whom conventional colonoscopy is contraindicated or where patients self-select to use imaging as their primary modality for initial colonic assessment. This updated guideline aims to provide a toolkit for both experienced imagers (and technologists) and for those considering launching this examination in their practice. There is guidance for reporting, optimal exam preparation, tips for problem solving to attain high quality examinations in challenging scenarios as well as suggestions for ongoing maintenance of competence. We also provide insight into the role of artificial intelligence and the utility of CTC in tumour staging of colorectal cancer. The appendices provide more detailed guidance into bowel preparation and reporting templates as well as useful information on polyp stratification and management strategies. Reading this guideline should equip the reader with the knowledge base to perform colonography but also provide an unbiased overview of its role in colon screening compared with other screening options. [ABSTRACT FROM AUTHOR]

BackgroundObesity and cardiometabolic dysfunction have been associated with cancer risk and severity. Underlying mechanisms remain unclear.ObjectivesThe aim of this study was to examine associations of obesity and related cardiometabolic traits with incident cancer.MethodsFHS (Framingham Heart Study) and PREVEND (Prevention of Renal and Vascular End-Stage Disease) study participants without prevalent cancer were studied, examining associations of obesity, body mass index (BMI), waist circumference, visceral adipose tissue (VAT) and subcutaneous adipose tissue depots, and C-reactive protein (CRP) with future cancer in Cox models.ResultsAmong 20,667 participants (mean age 50 years, 53% women), 2,619 cancer events were observed over a median follow-up duration of 15 years. Obesity was associated with increased risk for future gastrointestinal (HR: 1.30; 95% CI: 1.05-1.60), gynecologic (HR: 1.62; 95% CI: 1.08-2.45), and breast (HR: 1.32; 95% CI: 1.05-1.66) cancer and lower risk for lung cancer (HR: 0.62; 95% CI: 0.44-0.87). Similarly, waist circumference was associated with increased risk for overall, gastrointestinal, and gynecologic but not lung cancer. VAT but not subcutaneous adipose tissue was associated with risk for overall cancer (HR: 1.22; 95% CI: 1.05-1.43), lung cancer (HR: 1.92; 95% CI: 1.01-3.66), and melanoma (HR: 1.56; 95% CI: 1.02-2.38) independent of BMI. Last, higher CRP levels were associated with higher risk for overall, colorectal, and lung cancer (P < 0.05 for all).ConclusionsObesity and abdominal adiposity are associated with future risk for specific cancers (eg, gastrointestinal, gynecologic). Although obesity was associated with lower risk for lung cancer, greater VAT and CRP were associated with higher lung cancer risk after adjusting for BMI.

Background: This study was conducted to calculate the pulmonary arterial obstruction index (Qanadli index), evaluate its usefulness in patients with pulmonary thromboembolism, study the correlation between the pulmonary arterial obstruction index and right ventricular dilatation in patients with pulmonary thromboembolism, and investigate the correlation between the pulmonary artery obstructive index and right ventricular dysfunction in patients with pulmonary embolism. Methods: This was a hospital based cross-sectional study conducted among 50 patients who presented with pulmonary thromboembolism to the Department of Radiodiagnosis and Imageology, Kurnool Medical College, Kurnool, over a period of two years from November 2018 to November 2020, after obtaining clearance from the institutional ethics committee and written informed consent from the study participants. Results: Dyspnea and chest pain were present in 78% and 40% of the patients respectively. The maximum number of patients had an obstructive pulmonary index. Thrombus in the RT main pulmonary artery was present in 24 % of patients. LT main pulmonary artery in 18%. RT upper lobe segmental artery involved in 50%, RT middle lobe segmental artery in 72%, RT lower lobe segmental artery in 74%. LT upper lobe segmental artery involved in 36%, LT middle lobe segmental artery in 56%, LT lower lobe segmental artery in 62%. RT lung was involved more than LT lung. RV dilation measured in terms of relation to right and left ventricular measurements, RV/LV > 1 was present in 40%, <1 in 60%. RV dilatation was present in 20 patients out of 50. Out of 20 patients, 19 had a pulmonary artery obstructive index >45%; only one had a pulmonary artery obstructive index <45%. RV dysfunction was present in 19 cases. 15 patients had a pulmonary artery obstructive index >50%; four patients had a pulmonary artery obstructive index <50%. Conclusion: The specific index (the CT obstruction index) to quantify vascular obstruction in helical CT appears simple and reproducible. The CT obstruction score has considerable clinical and imaging impact, enabling accurate diagnosis, risk stratification, and patient selection for more aggressive treatment. There is a strong correlation between OI, RV dilatation, and RVD. [ABSTRACT FROM AUTHOR]

Background Limited cathartic preparations for CT colonography with fecal tagging can improve patient comfort but may result in nondiagnostic examinations from poorly tagged stool. Dual-energy CT may overcome this limitation by improving the conspicuity of the contrast agent, but more data are needed. Purpose To investigate whether dual-energy CT improves polyp detection in CT colonography compared with conventional CT at different fecal tagging levels in vitro. Materials and Methods In this HIPAA-compliant study, between December 2017 and August 2019, a colon phantom 30 cm in diameter containing 60 polyps of different shapes (spherical, ellipsoid, flat) and size groups (5-9 mm, 11-15 mm) was constructed and serially filled with simulated feces tagged with four different iodine concentrations (1.26, 2.45, 4.88, and 21.00 mg of iodine per milliliter), then it was scanned with dual-energy CT with and without an outer fat ring to simulate large body size (total diameter, 42 cm). Two readers independently reviewed conventional 120-kVp CT and 40-keV monoenergetic dual-energy CT images to record the presence of polyps and confidence (three-point scale.) Generalized estimating equations were used for sensitivity comparisons between conventional CT and dual-energy CT, and a Wilcoxon signed-rank test was used for reader confidence. Results Dual-energy CT had higher overall sensitivity for polyp detection than conventional CT (58.8%; 95% confidence interval [CI]: 49.7%, 67.3%; 564 of 960 polyps vs 42.1%; 95% CI: 32.1%, 52.8%; 404 of 960 polyps; P < .001), including with the fat ring (48% and 31%, P < .001). Reader confidence improved with dual-energy CT compared with conventional images on all tagging levels (P < .001). Interrater agreement was substantial (κ = 0.74; 95% CI: 0.70, 0.77). Conclusion Compared with conventional 120-kVp CT, dual-energy CT improved polyp detection and reader confidence in a dedicated dual-energy CT colonography phantom, especially with suboptimal fecal tagging. © RSNA, 2020.

• Based on CCTA data, two clusters could be identified in patients with CAD. • The clusters are significantly different in mortality, MI, and late revascularization risks. • The clusters are characterized by the severity of stenosis in coronary arteries. • The severity of stenosis in the LM coronary artery is the strongest risk factor. • Our CCTA classifier outperformed calcium, Framingham, and Duke scores in discerning the clusters. Risk-stratification of patients has a major role in the prevention and treatment of cardiovascular disease. The aim was to find the most informative predictors of cardiovascular events in patients undergoing Coronary CT Angiography. We carried out a secondary analysis of a large registry dataset. The included population comprises adults aged 18 or older who underwent Coronary CT Angiography of 64-detector rows or greater. We clustered patients based on their characteristics and compared the risk for poor clinical outcomes between the two clusters. There were two clusters of patients having different risks for all-cause death, myocardial infarction, and late revascularization [hazard ratios (95%CI) = 2.28 (2.02, 2.57), 1.63 (1.40, 1.89), and 2.46 (2.1, 2.88), all P < 0.001]. The severity of stenosis in the left main coronary artery adjusted for age and sex was the most significant predictor of the high-risk cluster [adjusted odds ratio (95%CI) = 3.35 (2.98, 3.77), P < 0.001]. The severity of stenosis in the first obtuse marginal branch of the left circumflex, distal left circumflex, distal left anterior descending, posterior descending, the first diagonal branch of the left anterior descending, and proximal right coronary artery were important as well (all adjusted odds ratios ≥ 2.52). Cluster profiling showed a higher performance for CT Angiography features (sensitivity = 97.4%, specificity = 85.7%, C-statistic = 98.7%) than calcium, Framingham, and Duke scores in identifying high-risk patients (C-statistic = 82.1, 77.0, and 88.2%, respectively). Coronary CT Angiography can accurately risk-stratify patients concerning poor clinical outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The aims are to evaluate the morphometry of the sellar region and propose a safety window on the floor of the sella turcica for the transsphenoidal approach in a Hispanic population. Materials and methods: We retrospectively analysed 150 computed tomographic angiography sellar region images from asymptomatic patients. The images were evaluated intraobservatory by an expert radiologist. We measured: intercarotid distance of cavernous segment; depth of sella turcica; skull base angle; anterior distance, the distance between anterior spinal nasal and floor of the sella turcica; posterior distance, the distance between anterior spinal nasal and posterior wall of the sella turcica; anterior surgical angle, formed between the floor of the nostril and superior limit of the anterior wall of the sella turcica; and posterior angle, formed between the floor of the nostril and the inferior limit of the posterior wall of the sella turcica. Results: Safety window was based on two measures: the intercarotid distance and depth. The mean of the safety window is 151.13 mm2 and 147.60 mm2 for men and women, respectively. The intercarotid distance was 17.83 mm. The depth of the sella turcica was 8.46 mm. The skull base angle was 112.13 grades. The anterior distance was 76.34 mm. The posterior distance was 87.59 mm. The anterior surgical angle was 32.76 grades. The posterior surgical angle was 87.59 grades. Conclusions: The surgical approach space is smaller in females. It could significate a more complicated surgery in this population. Anatomical understanding could reduce complications in hospitals without a neuronavigation system. [ABSTRACT FROM AUTHOR]

Objective: To investigate the CT findings of pulmonary infarction (PI) secondary to acute pulmonary embolism (APE). Method: The clinical and CT data of 41 patients with PI secondary to APE were analyzed retrospectively. The number, location, shape, margin of PI, pleural effusion and dynamic changes were summarized. Results: CT features of PI: (1) Number and location: Among the total 79 PI lesions, 18 patients had single lesion and 23 patients had multiple lesions. All lesions were located under the pleura and connected to the pleura with a broad base, 46.8% (37/79) were located in the lower lobe of the right lung, 36.7% (29/79) in the lower lobe of the left lung, 3.8% (3/79) in the upper lobe, 6.3% (5/79) in the middle lobe of the right lung, and 6.3% (5/79) in the lingual segment of the upper lobe of the left lung. (2) Shape: 45.6% (36/79) of the lesions showed Reversed Halo Sign (RHS), 36.7% (29/79) displayed consolidation of oval, wedge or hump, 17.7% (14/79) revealed ground glass opacity. (3) Bronchovascular bundles in PI: Bronchovascular bundles were found in 79.7% (63/79) of PI. In 21.3% (16/79) of the cases, there was no bronchovascular bundle in the lesion because of its small size; (4) After enhancement, there was no enhancement shown in the 79 PI lesions. (5) All 79 lesions changed into patchy or linear during the end of the treatment period. (6) Pleural effusion: 63.4% (26/41) of patients had pleural effusion, among whom 42.3% (11/26) had bilateral pleural effusion, and 57.7% (15/26) had unilateral pleural effusion. Conclusion: The imaging manifeatations of PE secondary to API hole certain characteristics. For single or multiple lesions under the pleura, with RHS, consolidation of wedge or hump, bronchovascular bundles, APE secondary to API should be considered. In addition, pleural effusion is helpful for diagnosis.

Objective: To describe CT findings and epidemiologic features of nasal and paranasal disease of rabbits (Oryctolagus cuniculus)., Methods: An electronic search was performed for rabbits that underwent skull CT from 2004 to 2024 and had findings consistent with nasal/paranasal or maxillary dental disease. History, signalment, and physical examination findings were recorded and reevaluated retrospectively for evidence of changes to the nasal passages, paranasal sinuses, and nearby associated anatomy. Data were analyzed with descriptive statistics, ordinal mixed logistic regression, and correlation analysis., Results: 100 studies from 69 rabbits were reviewed. Lop-eared rabbits represented 30 of 69 cases. Upper respiratory signs (48 of 69 [69.6%]) and dental-related disorders (21 of 69 [31.9%]) were primary complaints. Rhinitis (49 of 69 [71.0%]), sinusitis (50 of 69 [72.5%]), and both (40 of 69 [60.0%]) were most diagnosed, with turbinate destruction (48 of 69 [69.6%]) and alveolar bone loss of adjacent teeth (51 of 69 [73.9%]) being common findings. Sinusitis was most common in the ventral (48 of 50 [96.0%]) and dorsal (33 of 50 [66.0%]) recesses of the maxillary sinus. Multiple CT variables were significantly correlated (P < .05); of those, maxillary alveolar bone loss of the incisor teeth and the second premolar tooth were, respectively, correlated with rhinitis grade and with sinusitis and sinusitis grade within the ventral recess of the maxillary sinus (P < .001)., Conclusions: Computed tomographic evaluation allowed characterization of nasal and paranasal disease in rabbits and the association of rhinitis, sinusitis, and dental disease., Clinical Relevance: The correlation between the maxillary dentition, rhinitis, and sinusitis highlights the need for thorough evaluation in CT of the teeth in rabbits with upper respiratory signs.

Background and Objective: The imbalanced hemostatic equilibrium caused by brain tissue or vessel damage underlies the pathophysiology of traumatic brain injury (TBI)-induced coagulopathy, and cranial computed tomography (CT) is the gold standard for evaluating brain injury. The present study aimed to explore the correlation between quantitative cranial CT parameters and coagulopathy after TBI. Methods: We retrospectively collected the medical records of TBI patients with extracranial abbreviated injury scale (AIS) scores <3 who were admitted to our institution. The quantitative cranial CT parameters of patients with and without coagulopathy were compared, and univariate correlation analysis between CT parameters and coagulation subtest values and platelet counts was performed. The predictors for each subtest of coagulation function were probed by multivariate regression. Results: TBI patients with coagulopathy had a larger intracerebral haematoma/contusion (ICH/C) volume (p<0.001), a higher incidence of compressed basal cisterns (p=0.015), a higher Graeb score (p<0.001) and subarachnoid haematoma (Fisher's scaling score) (p=0.019) than those without coagulopathy. IH/C volume was identified as an independent risk factor for predicting coagulopathy. ICH/C volume showed a significantly positive correlation with APTT (Pearson's correlation = 0.333, p<0.001), while a significant negative correlation with PLT (Pearson's correlation = - 0.312, p<0.001). Conclusion: ICH/C volume was a main quantitative cranial CT parameter for predicting coagulopathy, suggesting that parenchymal brain damage and vessel injury were closely associated with coagulopathy after TBI. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the differentiation of premalignant from benign colorectal polyps detected by CT colonography using deep learning. Methods: In this retrospective analysis of an average risk colorectal cancer screening sample, polyps of all size categories and morphologies were manually segmented on supine and prone CT colonography images and classified as premalignant (adenoma) or benign (hyperplastic polyp or regular mucosa) according to histopathology. Two deep learning models SEG and noSEG were trained on 3D CT colonography image subvolumes to predict polyp class, and model SEG was additionally trained with polyp segmentation masks. Diagnostic performance was validated in an independent external multicentre test sample. Predictions were analysed with the visualisation technique Grad-CAM++. Results: The training set consisted of 107 colorectal polyps in 63 patients (mean age: 63 ± 8 years, 40 men) comprising 169 polyp segmentations. The external test set included 77 polyps in 59 patients comprising 118 polyp segmentations. Model SEG achieved a ROC-AUC of 0.83 and 80% sensitivity at 69% specificity for differentiating premalignant from benign polyps. Model noSEG yielded a ROC-AUC of 0.75, 80% sensitivity at 44% specificity, and an average Grad-CAM++ heatmap score of ≥ 0.25 in 90% of polyp tissue. Conclusions: In this proof-of-concept study, deep learning enabled the differentiation of premalignant from benign colorectal polyps detected with CT colonography and the visualisation of image regions important for predictions. The approach did not require polyp segmentation and thus has the potential to facilitate the identification of high-risk polyps as an automated second reader. Key Points: • Non-invasive deep learning image analysis may differentiate premalignant from benign colorectal polyps found in CT colonography scans. • Deep learning autonomously learned to focus on polyp tissue for predictions without the need for prior polyp segmentation by experts. • Deep learning potentially improves the diagnostic accuracy of CT colonography in colorectal cancer screening by allowing for a more precise selection of patients who would benefit from endoscopic polypectomy, especially for patients with polyps of 6–9 mm size. [ABSTRACT FROM AUTHOR]

Introduction: Accurate measurement of the aortic valve annulus is critical for proper valve sizing for the transcatheter aortic valve replacement (TAVR) procedure. While computed tomography angiography (CTA) is the widely-accepted standard, two-dimensional (2D) and three-dimensional(3D) transesophageal echocardiography (TEE) is commonly performed to measure the size of the aortic valve and to verify appropriate seating of prostheses. Methods: Patients undergoing TAVR between 2013-2015 were examined. 2D- and 3D-TEEmeasurements were compared to CTA taken as standard. Patients were followed for at least one year. The presence and effect of discrepancy (defined as a difference of more than 10%) between CTA and TEE measurements on survival were examined. Results: One hundred eighty-five patients (70 men) were included. 2D- and 3D-TEE measurements underestimated the annulus size by -1.49 and -1.32 mm, respectively. Discrepancies > 10% between TEE and CTA methods in estimating the aortic annulus size were associated with a decrease in post implant survival. The peak pressure gradient across the aortic prosthesis measured one year after the implant was higher in patients with an initial discrepancy between 3D-TEE and CTA measurements. In a multivariate cox-regression model, the discrepancy between CTA and 2D-TEE readings and the smaller size of the aortic annular area were the predictors of long-term survival. Conclusion: Both 2D and 3D-TEE underestimate the aortic annulus measurements compared to CTA, with 2D-TEE being relatively more precise than 3D-TEE technology. The presence of a discrepancy between echocardiographic and CTA measurements of the aortic annulus is associated with a lower survival rate.

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ObjectiveTo investigate the effects of 3 different bowel preparation protocols on interpretation of computed tomography (CT) pneumocolonography images.Study designExperimental crossover design.AnimalsIntact male, hound-cross, research colony dogs (n=4).MethodsAll dogs received the 3 different bowel preparation protocols for CT pneumocolonography in the same order, with a minimum of 2 weeks between protocols. For each segment of large bowel, the subjective adequacy of bowel cleansing was assessed, residual fecal and bowel volumes were calculated, and the density of fecal material in the bowel lumen was measured. Linear mixed effect models that included a random dog effect were used to evaluate mean differences in outcome measures across protocols.ResultsNo dogs experienced any clinical problems associated with the protocols or CT pneumocolonography. Bowel cleansing was considered adequate for CT pneumocolonography interpretation for all 3 protocols. There was a significant effect of protocol on residual fecal volumes and the fecal:bowel volume ratio, with the 2 protocols that included an extended fast producing the lowest total residual fecal volumes. There was a significant effect of protocol on maximum measured density of residual fecal material with the 2 protocols including iodinated contrast having the highest density.ConclusionsAll protocols were sufficient for CT pneumocolonography interpretation and contrast-tagging of residual fecal material was successful with oral iopamidol administration. An at-home bowel cleansing protocol may provide adequate bowel cleansing for CT pneumocolonography image interpretation.

ImportanceColorectal cancer is the second leading cause of cancer death in the United States. In 2016, an estimated 134,000 persons will be diagnosed with the disease, and about 49,000 will die from it. Colorectal cancer is most frequently diagnosed among adults aged 65 to 74 years; the median age at death from colorectal cancer is 68 years.ObjectiveTo update the 2008 US Preventive Services Task Force (USPSTF) recommendation on screening for colorectal cancer.Evidence reviewThe USPSTF reviewed the evidence on the effectiveness of screening with colonoscopy, flexible sigmoidoscopy, computed tomography colonography, the guaiac-based fecal occult blood test, the fecal immunochemical test, the multitargeted stool DNA test, and the methylated SEPT9 DNA test in reducing the incidence of and mortality from colorectal cancer or all-cause mortality; the harms of these screening tests; and the test performance characteristics of these tests for detecting adenomatous polyps, advanced adenomas based on size, or both, as well as colorectal cancer. The USPSTF also commissioned a comparative modeling study to provide information on optimal starting and stopping ages and screening intervals across the different available screening methods.FindingsThe USPSTF concludes with high certainty that screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years is of substantial net benefit. Multiple screening strategies are available to choose from, with different levels of evidence to support their effectiveness, as well as unique advantages and limitations, although there are no empirical data to demonstrate that any of the reviewed strategies provide a greater net benefit. Screening for colorectal cancer is a substantially underused preventive health strategy in the United States.Conclusions and recommendationsThe USPSTF recommends screening for colorectal cancer starting at age 50 years and continuing until age 75 years (A recommendation). The decision to screen for colorectal cancer in adults aged 76 to 85 years should be an individual one, taking into account the patient's overall health and prior screening history (C recommendation).

PurposeTo evaluate the ability of additional analysis of computed tomographic (CT) colonography images to provide a comprehensive osteoporosis assessment.Materials and methodsThis Health Insurance Portability and Accountability Act-compliant study was approved by our institutional review board with a waiver of informed consent. Diagnosis of osteoporosis and assessment of fracture risk were compared between biomechanical CT analysis and dual-energy x-ray absorptiometry (DXA) in 136 women (age range, 43-92 years), each of whom underwent CT colonography and DXA within a 6-month period (between January 2008 and April 2010). Blinded to the DXA data, biomechanical CT analysis was retrospectively applied to CT images by using phantomless calibration and finite element analysis to measure bone mineral density and bone strength at the hip and spine. Regression, Bland-Altman, and reclassification analyses and paired t tests were used to compare results.ResultsFor bone mineral density T scores at the femoral neck, biomechanical CT analysis was highly correlated (R(2) = 0.84) with DXA, did not differ from DXA (P = .15, paired t test), and was able to identify osteoporosis (as defined by DXA), with 100% sensitivity in eight of eight patients (95% confidence interval [CI]: 67.6%, 100%) and 98.4% specificity in 126 of 128 patients (95% CI: 94.5%, 99.6%). Considering both the hip and spine, the classification of patients at high risk for fracture by biomechanical CT analysis--those with osteoporosis or "fragile bone strength"--agreed well against classifications for clinical osteoporosis by DXA (T score ≤-2.5 at the hip or spine), with 82.8% sensitivity in 24 of 29 patients (95% CI: 65.4%, 92.4%) and 85.7% specificity in 66 of 77 patients (95% CI: 76.2%, 91.8%).ConclusionRetrospective biomechanical CT analysis of CT colonography for colorectal cancer screening provides a comprehensive osteoporosis assessment without requiring changes in imaging protocols.

ABSTRACT: The diagnosis of several diseases in chelonians is a challenge in the veterinary clinic, because a detailed physical examination with auscultation and palpation is difficult due the presence of carapace and plastron. Imaging analysis such as radiography and computed tomography (CT) have been shown to be beneficial for diagnosis, prognosis and treatment in numerous animal species. Thus, this study aimed to identify and describe the structures of the lower respiratory tract in red-foot tortoises, by computed tomography, radiography and gross anatomy in twelve red-foot tortoises (Chelonoidis carbonaria), adults and of both sexes. The lower respiratory tract in these animals comprised the larynx, trachea, bronchi and the lungs. The presence of epiglottic cartilage was not observed in the animals studied. CT allowed the observation of the intrapulmonary part of the bronchi, which was accompanied by large intrapulmonary blood vessels. The lungs presented a reticulated parenchyma, without lobulations. Each lung had a small chamber located near the cranial and caudal poles. These structures were identified in CT and 3D CT reconstructions and these could suggest that these chambers could be non-respiratory structures, and could be comparable to the air sacs of birds. This study establishes normal CT anatomy of the lower respiratory tract of the red-foot tortoise; and may be used as a reference in the assessment of respiratory disorders in this tortoise.

Introduction: Mild stenosis [degree of stenosis (DS) < 50%] is commonly labeled as nonobstructive lesion. Some lesions remain stable for several years, while others precipitate acute coronary syndromes (ACS) rapidly. The causes of ACS and the factors leading to diverse clinical outcomes remain unclear. Method: This study aimed to investigate the hemodynamic influence of mild stenosis morphologies in different coronary arteries. The stenoses were modeled with different morphologies based on a healthy individual data. Computational fluid dynamics analysis was used to obtain hemodynamic characteristics, including flow waveforms, fractional flow reserve (FFR), flow streamlines, time-average wall shear stress (TAWSS), and oscillatory shear index (OSI). Results: Numerical simulation indicated significant hemodynamic differences among different DS and locations. In the 20%-30% range, significant large, low-velocity vortexes resulted in low TAWSS (<4 dyne/cm 2 ) around stenoses. In the 30%-50% range, high flow velocity due to lumen area reduction resulted in high TAWSS (>40 dyne/cm 2 ), rapidly expanding the high TAWSS area (averagely increased by 0.46 cm 2 ) in left main artery and left anterior descending artery (LAD), where high OSI areas remained extensive (>0.19 cm 2 ). Discussion: While mild stenosis does not pose any immediate ischemic risk due to a FFR > 0.95, 20%-50% stenosis requires attention and further subdivision based on location is essential. Rapid progression is a danger for lesions with 20%-30% DS near the stenoses and in the proximal LAD, while lesions with 30%-50% DS can cause plaque injury and rupture. These findings support clinical practice in early assessment, monitoring, and preventive treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Cao, Li, Chen, Peng, Zheng and Chen.)

Objectives of this prospective study were to describe effects of varying technical components that may contribute to an optimal protocol for computed tomographic pneumocolonography (CTP) in dogs, and to develop a standardized methodology for CTP as a future potential diagnostic tool in canine clinical patients with large bowel disease. Eight purpose-bred intact male hound cross-research dogs were enrolled and randomized to groups based on variables of pressure/body position (n = 4) and insufflation time (n = 4). For each segment of large bowel (rectum, colorectal junction, descending colon, transverse colon, ascending colon), the adequacy of bowel preparation, % of bowel lumen filled with fecal material, and bowel tortuosity or folding were assessed. Measurements of bowel wall thickness (cm), cross-sectional bowel lumen diameter (cm), and cross-sectional bowel luminal area (cm(2) ) were obtained at standardized locations within the large bowel. False discovery rates (FDR) were calculated to adjust for multiple testing. Values of FDR < 0.05 were considered significant. Differences in mean cross-sectional area and diameter and bowel wall thickness under increasing pressure were not significant after adjusting for multiple testing; some had raw p values

Introduction: Accurate measurement of the aortic valve annulus is critical for proper valve sizing for the transcatheter aortic valve replacement (TAVR) procedure. While computed tomography angiography (CTA) is the widely-accepted standard, two-dimensional (2D) and three-dimensional(3D) transesophageal echocardiography (TEE) is commonly performed to measure the size of the aortic valve and to verify appropriate seating of prostheses. Methods: Patients undergoing TAVR between 2013-2015 were examined. 2D- and 3D-TEEmeasurements were compared to CTA taken as standard. Patients were followed for at least one year. The presence and effect of discrepancy (defined as a difference of more than 10%) between CTA and TEE measurements on survival were examined. Results: One hundred eighty-five patients (70 men) were included. 2D- and 3D-TEE measurements underestimated the annulus size by -1.49 and -1.32 mm, respectively. Discrepancies > 10% between TEE and CTA methods in estimating the aortic annulus size were associated with a decrease in post implant survival. The peak pressure gradient across the aortic prosthesis measured one year after the implant was higher in patients with an initial discrepancy between 3D-TEE and CTA measurements. In a multivariate cox-regression model, the discrepancy between CTA and 2D-TEE readings and the smaller size of the aortic annular area were the predictors of long-term survival. Conclusion: Both 2D and 3D-TEE underestimate the aortic annulus measurements compared to CTA, with 2D-TEE being relatively more precise than 3D-TEE technology. The presence of a discrepancy between echocardiographic and CTA measurements of the aortic annulus is associated with a lower survival rate. [ABSTRACT FROM AUTHOR]

Introduction: Computed tomographic (CT) phenotypic patterns of chronic obstructive pulmonary disease (COPD) identify different clinical features of disease. The impact of these variables on the physiological response to exercise has been the focus of a great deal of research as it allows more individualized clinical approaches. The aim of our study was to evaluate the relationships between CT phenotyping of subjects with COPD and the ventilatory response during cardiopulmonary exercise testing (CPET)., Methods: Subjects with COPD were classified into four phenotypes based on CT metrics of emphysema (low attenuation area less than a threshold of -950 Hounsfield [%LAA-950]) and airwall thickness (bronchial wall area percentage [%WA])., Results: Eighty COPD patients (78.8% males, median age 65±11.3 years) were enrolled in the study. Based on CT phenotype, 25 (31.3%) patients were classified as normal, 27 (33.8%) air dominant, 17 (21.3%) emphysema dominant and 11 (13.8%) mixed type. The emphysema and mixed phenotypes showed the highest ventilatory equivalent for carbon dioxide (V E /VCO 2 ) and V E /VCO 2 slope (p<0,05). In all phenotypes, %LAA was positive correlated with V E /VCO 2 and V E /VCO 2 slope (r = 0.437, p = 0.006 and r = 0.503, p<0.001, respectively). %WA also showed a positive correlation with V E /VCO 2 and V E /VCO 2 slope (r = 0.541, p<0.001 and r = 0.299, p = 0.033, respectively). In multivariate regression models, after adjustment for age, BMI, sex and FEV1, %LAA was the only independent predictor of V E /VCO 2 and V E /VCO 2 slope (β 0.343, SE 0.147, 95% CI 0.009/0.610, p = 0.044 and β 0.496, SE 0.081, 95% CI 0.130/0.455, p = 0.001, respectively)., Conclusion: Emphysema (%LAA) and airways metrics (%WA) had strong relationships with the different characteristics of ventilatory response to exercise in subjects with mild to moderate COPD. In particular, %LAA seemed to play an important role as an independent predictor of V E /VCO 2 and V E /VCO 2 slope. These results suggested that CT phenotyping may help predicting ventilatory response to exercise in subjects with COPD., Competing Interests: Conflicts of interest The authors have no conflicts of interest to declare., (Copyright © 2022 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: The present analysis aims to describe a surgical approach wherein pulsatile tinnitus (PT) arising due to sigmoid sinus wall anomalies (SSWA) can be treated via combination internal and external sigmoid sinus wall reconstruction. We further evaluated the utility of temporal bone 3D-CT imaging during both the pre- and post-operative assessments of all treated patients. Methods: Data pertaining to 11 patients that had undergone sigmoid sinus wall reconstruction were retrospectively analyzed. All of these patients underwent preoperative 3D-CT imaging assessment. These patients were additionally subjected to sigmoid sinus wall reconstruction via a combined internal and external layer approach. Postoperatively, all patients underwent a radiological assessment of auricular cartilage and autologous bone powered displacement. Patients were additionally asked about any subjective changes in PT or associated symptoms at follow-up time points. Results: SSWA in the 3D-CT imaging from these patients were all distinct. In 10/11 patients, PT fully resolved following reconstruction of the sinus wall. The remaining patients exhibited significant improvements in symptoms postoperatively, with PT fully resolving within a 1-month follow-up period. No patients suffered any major complications. Conclusions: Temporal bone 3D-CT imaging allow for effective visualization of SSWA, enabling effective pre- and post-operative assessments of treated patients. A combined internal and external layer approach to sigmoid sinus wall reconstruction can be implemented safely and effectively, yielding high rates of satisfactory outcomes and achieving rigid reconstruction of this surface. As such, there is clear value in the consideration of this approach when treating individuals suffering from PT as a result of SSWA. [ABSTRACT FROM AUTHOR]

Background: In December 2019, an outbreak of a novel coronavirus disease (COVID-19; previously known as 2019-nCoV) was reported in Wuhan, Hubei province, China, which has subsequently affected more than 200 countries worldwide including Europe, North America, Oceania, Africa and other places. The number of infected people is rapidly increasing, while the diagnostic method of COVID-19 is only by nucleic acid testing. Objective: To explain the epidemiological characteristics, clinical features, imaging manifestations and to judge diagnostic value of COVID-19 by analyzing the clinical data of COVID-19 suspected and confirmed patients in a non-outbreak, Shanghai, China. To clarify the early epidemiology and clinical characteristics about COVID-19. Methods: Cross-sectional, single-center case reports of the 86 patients screened at Zhoupu Hospital in Pudong New District, Shanghai, China, from January 23 to February 16, 2020. Epidemiology, demography, clinical, laboratory and chest CTs were collected and analyzed. The screened patients were divided into COVID-19 and non-COVID-19 based on nucleic acid test results. Results: Of the 86 screened patients, 11 were confirmed (12.8%) by nucleic acid testing (mean age 40.73 ± 11.32, 5 males). No significant differences were found in clinical symptoms including fever, cough, dyspnea, sore throat, and fatigue (P > 0.05). No statistical difference was observed in plasma C-reactive protein (CRP) between the two groups (COVID-19 and non-COVID-19 ) of patients (P = 0.402), while the white blood cell count and lymphocyte count of the confirmed patients were slightly lower than those of the suspected patients (P < 0.05). Some non-COVID-19 chest CTs also showed subpleural lesions, such as ground-glass opacities (GGO) combined with bronchiectasis; or halo nodules distributed under the pleura with focal GGO; consolidation of subpleural distribution or combined with air bronchi sign and vascular bundle sign, etc. Conclusion: The early clinical manifestations and imaging findings of COVID-19 are not characteristic in non-outbreak areas. Etiological testing should be performed as early as possible for clinically suspected patients. [ABSTRACT FROM AUTHOR]

There are many factors affecting the successful performance of CT colonography (CTC). Adequate colonic cleansing and distention, the optimal CT technique and interpretation with using the newest CTC software by a trained reader will help ensure high accuracy for lesion detection. Fecal and fluid tagging may improve the diagnostic accuracy and allow for reduced bowel preparation. Automated carbon dioxide insufflation is more efficient and may be safer for colonic distention as compared to manual room air insufflation. CT scanning should use thin collimation of < or =3 mm with a reconstruction interval of < or =1.5 mm and a low radiation dose. There is not any one correct method for the interpretation of CTC; therefore, readers should be well-versed with both the primary 3D and 2D reviews. Polyps detected at CTC should be measured accurately and reported following the "polyp size-based" patient management system. The time-intensive nature of CTC and the limited resources for training radiologists appear to be the major barriers for implementing CTC in Korea.

Background: HIV/AIDS patients do have variable neurological manifestation of the disease that will require neuro-imaging for proper evaluation. Computed tomography is one of the neuroimaging techniques that can be used for diagnostic work up of patients with neurological symptoms and signs. Objective: To determine the spectrum of cranial computed tomographic findings in HIV/AIDS patients with neurological signs and symptoms and correlate with CD4 count. Methodology: This is a retrospective analysis of 43 HIV/AIDS patients who presented with neurological signs and symptoms and had cranial computed tomography from December 2014 to June 2018 (43 months). Results: The mean age of subjects studied was 29±17 years with age range of 21-47 years. There were 27 males and 16 females with male to female ratio 1.7:1. Nineteen (44.2%) patients presented with one neurological sign and twenty-four (55.8%) presented with more than one neurological sign. Thirty-six (83.7%) of patients had abnormal CT findings. Cranial computed tomographic findings were cerebral infracts (27.9%), cerebral mass (18.6%), cerebral atrophy (16.3%), haemorrhage (7%). Others were meningeal enhancement (4.7%), brain oedema (4.7%) and white matter lesion (4.7%). Cerebral mass was the most common CT findings in patient with CD4 count less than 200cells/mm3. In subjects with CD4 count of 200-499 cells/mm3 and greater than 500cells/mm3, cerebral infracts and atrophy were the commonest CT findings respectively. There was statistically significant association between CD4 counts and abnormal CT findings in relation to cerebral infract and atrophy (cerebral infarcts, p=0.02 and cerebral atrophy p=0.02). Conclusion: Cerebral infracts was the commonest CT findings in this study. CT plays an important role in evaluation of HIV/AIDS patient with neurological features. CT scan should be a routine investigation in HIV/AIDS patients with low CD4 count presenting with neurological signs and symptoms in view of the abnormalities seen in them from our study. [ABSTRACT FROM AUTHOR]

Assess the prevalence of neoplasia ≥6 mm at repeat CT colonoscopy (CTC) in individuals with no significant lesions at baseline. Individuals aged ≥18 years, with/without CRC risk factors, with no polyps ≥6 mm on baseline CTC (negative baseline) who underwent repeat CTC in a large HMO from 2001 to 2011 were retrospectively identified. Studies were reviewed by board-certified radiologists with experience interpreting CTC. Demographic details, CRC risk factors, and the number, size, and location of incident lesions were noted. Findings were classified using the C-RADS scale. Lesion prevalence at CTC-2 was determined, and study interval and risk characteristics of patients with- and without findings were compared. Our study included 636 individuals (369 men [58.0%]; mean age 59.9 years) with negative baseline CTC who underwent repeat CTC after a mean 4.6 year interval (SD 1.6 years). At baseline, 469/636 (73.7%) were at average risk for CRC; 418 remained at average risk for CTC-2 with 51 (8.0%) developing new risk factors in the interval between studies. At CTC-2, 47 participants (7.4%) presented 52 significant neoplasia: 35 polyps 6–9 mm, 14 polyps ≥10 mm, and 3 masses in 3/636 participants (0.47%). 2/3 masses, 6/14 polyps ≥10 mm (42.9%), and 12/25 polyps 6–9 mm (48.0%) were in individuals with risk factors for CRC. Histopathology was available for 12/52 lesions (23.1%): 8 tubular adenomas, 2 villous adenomas, 1 hamartomatous polyp, 1 case of normal tissue. A mean 4.6 years after negative-baseline CTC, neoplasia ≥6 mm were seen in 7.4% of participants, including masses in 0.47%, supporting recommendations for a 5-year study interval. • Prevalence of neoplasia at repeat CTC after a negative baseline exam was assessed. • 3 masses were detected in 3/636 participants (0.47%) at a mean 4.6-year interval. • 52 neoplasia ≥6 mm were found in 7.4% of participants, with/without risk factors. • This supports recommendations for a 5-year interval after negative baseline CTC. [ABSTRACT FROM AUTHOR]