Effect of Averaging Measurements From Multiple MRI Pulse Sequences on Kidney Volume Reproducibility in Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Total kidney volume (TKV) is an important biomarker for assessing kidney function, especially for autosomal dominant polycystic kidney disease (ADPKD). However, TKV measurements from a single MRI pulse sequence have limited reproducibility, ± ~5%, similar to ADPKD annual kidney growth rates. PURPOSE: To improve TKV measurement reproducibility on MRI by extending artificial intelligence algorithms to automatically segment kidneys on T1-weighted, T2-weighted, and steady state free precession (SSFP) sequences in axial and coronal planes and averaging measurements. STUDY TYPE: Retrospective training, prospective testing. SUBJECTS: Three hundred ninety-seven patients (356 with ADPKD, 41 without), 75% for training and 25% for validation, 40 ADPKD patients for testing and 17 ADPKD patients for assessing reproducibility. FIELD STRENGTH/SEQUENCE: T2-weighted single-shot fast spin echo (T2), SSFP, and T1-weighted 3D spoiled gradient echo (T1) at 1.5 and 3T. ASSESSMENT: 2D U-net segmentation algorithm was trained on images from all sequences. Five observers independently measured each kidney volume manually on axial T2 and using model-assisted segmentations on all sequences and image plane orientations for two MRI exams in two sessions separated by 1-3 weeks to assess reproducibility. Manual and model-assisted segmentation times were recorded. STATISTICAL TESTS: Bland-Altman, Schapiro-Wilk (normality assessment), Pearson's chi-squared (categorical variables); Dice similarity coefficient, interclass correlation coefficient, and concordance correlation coefficient for analyzing TKV reproducibility. P-value < 0.05 was considered statistically significant. RESULTS: In 17 ADPKD subjects, model-assisted segmentations of axial T2 images were significantly faster than manual segmentations (2:49 minute vs. 11:34 minute), with no significant absolute percent difference in TKV (5.9% vs. 5.3%, P = 0.88) between scans 1 and 2. Absolute percent differences between the two scans for model-assisted segmentations on other sequences were 5.5% (axial T1), 4.5% (axial SSFP), 4.1% (coronal SSFP), and 3.2% (coronal T2). Averaging measurements from all five model-assisted segmentations significantly reduced absolute percent difference to 2.5%, further improving to 2.1% after excluding an outlier. DATA CONCLUSION: Measuring TKV on multiple MRI pulse sequences in coronal and axial planes is practical with deep learning model-assisted segmentations and can improve TKV measurement reproducibility more than 2-fold in ADPKD. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Clinical outcomes and the impact of valve morphology for transcatheter aortic valve replacement in bicuspid aortic valves: A systematic review and meta-analysis.

BACKGROUND: Bicuspid aortic valve (BAV) is present in approximately 0.5%-2% of the general population, causing significant aortic stenosis (AS) in 12%-37% of affected individuals. Transcatheter aortic valve replacement (TAVR) is being considered the treatment of choice in patients with symptomatic AS across all risk spectra. AIM: Aim Our study aims to compare TAVR outcomes in patients with BAV versus tricuspid aortic valves (TAV). METHODS: A comprehensive literature search was performed in PubMed, Web of Science, and Cochrane trials. Studies were included if they included BAV and TAV patients undergoing TAVR with quantitative data available for at least one of our predefined outcomes. Meta-analysis was performed by the random-effects model using Stata software. RESULTS: Fifty studies of 203,288 patients were included. BAV patients had increased 30-day all-cause mortality (odds ratio [OR] = 1.23 [1.00-1.50], p = 0.05), in-hospital stroke (OR = 1.39 [1.01-1.93], p = 0.05), in-hospital and 30-day PPI (OR = 1.13 [1.00-1.27], p = 0.04; OR = 1.16 [1.04-1.13], p = 0.01) and in-hospital, 30-day and 1-year aortic regurgitation (AR) (OR = 1.48 [1.19-1.83], p < 0.01; OR = 1.79 [1.26-2.52], p < 0.01; OR = 1.64 [1.03-2.60], p = 0.04). Subgroup analysis on new-generation valves showed a reduced 1-year all-cause mortality (OR = 0.86 [CI = 0.75-0.98], p = 0.03), despite higher in-hospital and 30-day PPI (OR = 0.1.21 [1.04-1.41], p = 0.01; OR = 1.17 [1.05-1.31], p = 0.01) and in-hospital AR (OR = 1.62 [1.14-2.31], p = 0.01) in the BAV group. The quality of included studies was moderate-to-high, and only three analyses presented high heterogeneity. CONCLUSION: TAVR is associated with comparable outcomes in patients with BAV and TAV. Careful selection of BAV cases by preprocedural assessment of valve anatomy and burden of calcification, pre- and post-procedural dilation, and implementing newer generations of valves may improve the safety and efficacy of TAVR in BAV patients.

In CV disease, clopidogrel reduces nonfatal MI and MACE vs. aspirin but not stroke or mortality.

SOURCE CITATION: Tasoudis PT, Kyriakoulis IG, Sagris D, et al. Clopidogrel monotherapy versus aspirin monotherapy in patients with established cardiovascular disease: systematic review and meta-analysis. Thromb Haemost. 2022;122:1879-87. 35577054.

Nationwide Analysis of the Outcomes and Mortality of Hospitalized Infants with Concomitant Diagnosis of COVID-19.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) generally causes milder illness in the pediatric population. However, infants represent a higher-risk population with evolving symptomatology and severity. There is a paucity of large population-based data on the impact of COVID-19 on hospitalized infants. STUDY DESIGN: In this large cohort study, the National Inpatient Sample database was queried for all infant hospital admissions between January and December 2020 in the United States, with and without a diagnosis of COVID-19 based on ICD-10-CM U07. The mortality and morbidity of infants with and without COVID-19 were evaluated. Parent-reported race and outcomes were also analyzed. RESULTS: A weighted total of 3,754,236 infants who were hospitalized were identified, of which 4,265 patients (0.11%) had a concomitant diagnosis of COVID-19. Infants with COVID-19 had similar mortality and extracorporeal membrane oxygenation utilization. Infants with concomitant COVID-19 had a higher rate of respiratory failure, congestive heart failure, acute kidney injury, and coagulopathy. Compared with Caucasian infants and Asian infants, Hispanic and African American infants were more likely to have COVID-19 hospital admissions than hospitalizations without COVID-19 diagnosis. Patients with lower median household income represented the majority of the COVID-19 hospitalization. The infants with COVID-19 were more likely to have Medicaid or Medicare insurance and less likely to have private insurance. CONCLUSION: In this large cohort of hospitalized infants with COVID-19, the infection was associated with complications, including respiratory failure and endotracheal intubations but not associated with a higher risk for mortality. Infants from racial minorities and lower socioeconomic strata carry the highest burden of COVID-19 infection. KEY POINTS: · Infants with COVID-19 represent a higher-risk group with evolving symptomatology and severity.. · Infants with COVID-19 had similar mortality rates and extracorporeal membrane oxygenation utilization as those without COVID-19.. · Racial minorities and lower socioeconomic strata carry the highest burden of COVID-19 infection..

No Significant Difference in Post-ERCP Bleeding Rates Between Dual Antiplatelet Agents and Aspirin Alone: A Systematic Review and Meta-analysis.

BACKGROUND: Several professional society guidelines suggest holding antiplatelet agents before high-risk procedures. However, there is lack of high-grade evidence to support the recommendation as most of the studies have been single center with small sample sizes. We aimed to perform the first systematic review and meta-analysis comparing dual antiplatelet therapy (DAPT) versus aspirin alone in terms of postendoscopic retrograde cholangiopancreatography (ERCP) bleeding. METHODS: Three independent reviewers performed a comprehensive review of all original articles published from inception to May 2020, evaluating the post-ERCP bleeding rate in setting of DAPT. Primary outcomes were the overall post-ERCP bleeding rate with the use of dual antiplatelet therapy; comparison of post-ERCP bleeding rate in patients with DAPT versus aspirin alone. Secondary outcomes were comparison of immediate and delayed post-ERCP bleeding outcomes in the 2 cohorts. RESULTS: Six studies were included after a thorough search was concluded using the key words. The pooled analysis of studies revealed an overall post-ERCP bleeding rate of 5.7% (95% confidence interval: 3-10.6) on sustained DAPT. Post-ERCP bleeding in DAPT Cohort was not significantly higher as compared with aspirin only Cohort (odds ratio: 1.14, 95% confidence interval: 0.46-2.81). The immediate bleeding and delayed bleeding rates cannot be generalized due to low number of studies. CONCLUSIONS: The first systematic review and meta-analysis showed that post-ERCP bleeding rates are not significantly higher in DAPT cohort as compared with aspirin alone. Therefore, the risk of bleeding is less likely related to the antiplatelet agents and more likely related to the procedure itself.

Safety and Efficacy of Thrombin for Bleeding Gastric Varices: A Systematic Review and Meta-Analysis.

INTRODUCTION: The optimal therapy for bleeding-related gastric varices is still a controversial topic. There is a paucity of literature that comprehensively summarizes the available literature regarding safety and efficacy of thrombin in bleeding gastric varices. METHODS: Four independent reviewers performed a comprehensive review of all original articles published from inception to October 2020, describing the use of thrombin for management of bleeding gastric varices. Primary outcomes were (1) pooled early and late rebleeding rate, (2) pooled gastric variceal related mortality rate, (3) pooled rescue therapy rate, and (4) pooled adverse event rate with the use of thrombin in bleeding gastric varices. The meta-analysis was performed and the statistics were two-tailed. Finally, probability of publication bias was assessed using funnel plots and with Egger's test. RESULTS: Eleven studies were included in the analysis after comprehensive search. This yielded a pooled early rebleeding rate of 9.3% (95% CI 4.9-17) and late rebleeding rate 13.8% (95% CI 9-20.4). Pooled rescue therapy rate after injecting thrombin in bleeding gastric varices was 10.1% (95% CI 6.1-16.3). The pooled 6-week gastric variceal-related mortality rate after injecting thrombin in bleeding gastric varices was 7.6% (95% CI 4.5-12.5). There were a total of four adverse events out of a total of 222 patients with pooled adverse event rate after injecting thrombin in bleeding gastric varices was 5.6% (95% CI 2.9-10.6). CONCLUSION: In summary, the systematic review and meta-analysis on the use of thrombin for bleeding gastric varices suggest low rates of rebleeding and minimal rates of adverse events. While, early and late rebleeding rate and rescue therapy rate are similar to cyanoacrylate-based therapy, the minimal rates of adverse events are perhaps the most important benefit of thrombin. Thus, the current data suggest that thrombin is a very promising therapeutic alternative with low risk of adverse events for bleeding gastric varices.

Acute pancreatitis in patients with COVID-19 is more severe and lethal: a systematic review and meta-analysis.

BACKGROUND: Emerging evidence suggests an association between acute pancreatitis and COVID-19. Our objective is to conduct a systematic review and meta-analysis to evaluate whether COVID-19 affects the severity and outcomes associated with acute pancreatitis. METHODS: Cochrane guidelines and PRISMA statement were followed for this review. Digital dissertation bases were searched and all studies comparing the outcomes of acute pancreatitis amongst patients with and without COVID-19 were included. We compared the etiology, severity, length of hospital stay and mortality associated with acute pancreatitis in patients with and without COVID-19. RESULTS: Four observational studies with a total of 2,419 patients were included in the review. Presence of COVID-19 significantly increased the odds of mortality (OR 4.10, 95% CI 2.03-8.29) in patients with acute pancreatitis. These patients also had an increased incidence of severe pancreatitis (OR 3.51, 95% CI 1.19-10.32), necrotizing pancreatitis (OR 1.84, 95% CI 1.19-2.85) and a longer length of hospital stay (OR 2.88, 95% CI 1.50-5.52), compared to non-COVID patients. Patients with COVID-19 were more likely to have an unknown or idiopathic etiology of acute pancreatitis (OR 4.02, 95% CI 1.32-12.29), compared to non-COVID-19 patients. CONCLUSION: Current evidence suggests that COVID-19 adversely impacts the morbidity and mortality associated with acute pancreatitis. SARS-CoV-2 may be a causative agent for acute pancreatitis. Further population-based studies are needed to confirm or refute these findings.

Direct Oral Anticoagulants Versus Warfarin in Left Ventricular Thrombus: A Systematic Review and Meta-Analysis.

BACKGROUND: There are conflicting results regarding the safety and efficacy of direct oral anticoagulants (DOACs) in the management of left ventricular thrombus (LVT) compared with the vitamin K antagonist warfarin. STUDY QUESTION: What is the safety and efficacy of DOACs in the management of LVT compared with warfarin? DATA SOURCE: Randomized clinical trials and cohort studies in the MEDLINE and Cochrane databases from inception till April 4, 2021. STUDY DESIGN: The present analysis is a systematic review and meta-analysis. Desired outcomes were all-cause mortality, complete resolution of LVT, stroke and systemic emboli, and major bleeding. The risk ratio (RR) of the outcomes and 95% confidence intervals (CIs) were calculated using a random-effects modeling approach. RESULTS: Twelve studies with a total of 2322 patients were included. There was no difference between the 2 interventions in the resolution of LVT [RR 0.97 (CI 0.93-1.02)], stroke and systemic embolism [RR 0.95 (CI 0.63-1.45)], bleeding [RR 1.14 (CI 0.81-1.60)], and all-cause mortality [RR 0.99 (CI 0.67, 1.46)]. CONCLUSIONS: DOACs and warfarin have comparable safety and efficacy outcomes in the management of LVT.

Incidence of Non-variceal Upper Gastrointestinal Bleeding Worsens Outcomes with Acute Coronary Syndrome: Result of a National Cohort.

INTRODUCTION: Upper gastrointestinal bleeding (UGIB) is a feared complication of acute coronary syndrome (ACS) and has been shown to increase morbidity and mortality. Our aim was to assess the incidence of non-variceal UGIB in patients with ACS in a national cohort and its impact on in-hospital mortality, length of stay (LOS), and cost of hospitalization. METHODS: This was a retrospective cohort study analyzing the 2016 Nationwide Inpatient Sample (NIS) utilizing ICD 10 CM codes. Principal discharge diagnoses of ACS (STEMI, NSTEMI, and UA) in patients over 18 years old were included. Non-variceal UGIB with interventions including endoscopy, angiography, and embolization were also evaluated. Primary outcome was the national incidence of concomitant non-variceal UGIB in the setting of ACS. Secondary outcomes included in-hospital mortality, length of stay, and cost of stay. RESULTS: A total of 661,404 discharges with principal discharge diagnosis of ACS in 2016 were analyzed. Of the included cohort, 0.80% (n = 5324) were complicated with non-variceal UGIB with increased frequency in older patients (OR 1.03, 95% CI 1.03-1.04; p = 0.0001). Despite endoscopic evaluation, 17.35% (n = 744) underwent angiography. After adjustment of confounders, inpatient mortality was significantly higher in patients with UGIB (OR 2.07, 95% CI 1.63-2.63, p = 0.0001). Non-variceal UGIB also led to significantly longer LOS (10.38 days vs 4.37 days, p = 0.0001) and cost of stay ($177,324 vs $88,468, p = 0.0001). DISCUSSION: Our study shows that the national incidence of non-variceal UGIB complicating ACS is low at less than 1%, but resulted in significantly higher inpatient mortality, LOS, and hospitalization charges.

Evaluation of a standardised Vi poly-l-lysine ELISA for serology of Vi capsular polysaccharide antibodies.

Typhoid vaccines based on protein-conjugated capsular Vi polysaccharide (TCVs) prevent typhoid in infants and young children. Analysis of the serum anti-Vi IgG response following immunisation against typhoid confirms the immunogenicity of TCVs and forms an important part of the pathway to licensing. Comparative studies could expedite the licencing process, and the availability of a standardised ELISA method alongside the 1st International Standard (IS) 16/138 for anti-typhoid capsular Vi polysaccharide IgG (human) will facilitate this process. To this end, a non-commercial ELISA based on a coat of Vi and poly-l-lysine (Vi-PLL ELISA) was evaluated by 10 laboratories. Eight serum samples, including IS 16/138, were tested in the standardised Vi-PLL ELISA (n = 10), a commercial Vi ELISA (n = 3) and a biotinylated Vi ELISA (n = 1). Valid estimates of potencies relative to IS 16/138 were obtained for all samples in the Vi-PLL ELISA and the commercial ELISA, with good repeatability and reproducibility evident from the study results and concordant estimates obtained by the two ELISA methods. The study demonstrates that the Vi-PLL ELISA can be used in clinical trial studies to determine the immunogenicity of TCVs.

Advanced Deep Learning Techniques Applied to Automated Femoral Neck Fracture Detection and Classification.

To use deep learning with advanced data augmentation to accurately diagnose and classify femoral neck fractures. A retrospective study of patients with femoral neck fractures was performed. One thousand sixty-three AP hip radiographs were obtained from 550 patients. Ground truth labels of Garden fracture classification were applied as follows: (1) 127 Garden I and II fracture radiographs, (2) 610 Garden III and IV fracture radiographs, and (3) 326 normal hip radiographs. After localization by an initial network, a second CNN classified the images as Garden I/II fracture, Garden III/IV fracture, or no fracture. Advanced data augmentation techniques expanded the training set: (1) generative adversarial network (GAN); (2) digitally reconstructed radiographs (DRRs) from preoperative hip CT scans. In all, 9063 images, real and generated, were available for training and testing. A deep neural network was designed and tuned based on a 20% validation group. A holdout test dataset consisted of 105 real images, 35 in each class. Two class prediction of fracture versus no fracture (AUC 0.92): accuracy 92.3%, sensitivity 0.91, specificity 0.93, PPV 0.96, NPV 0.86. Three class prediction of Garden I/II, Garden III/IV, or normal (AUC 0.96): accuracy 86.0%, sensitivity 0.79, specificity 0.90, PPV 0.80, NPV 0.90. Without any advanced augmentation, the AUC for two-class prediction was 0.80. With DRR as the only advanced augmentation, AUC was 0.91 and with GAN only AUC was 0.87. GANs and DRRs can be used to improve the accuracy of a tool to diagnose and classify femoral neck fractures.

Breast MRI screening for average-risk women: A monte carlo simulation cost-benefit analysis.

BACKGROUND: Screening high-risk women for breast cancer with MRI is cost-effective, with increasing cost-effectiveness paralleling increasing risk. However, for average-risk women cost is considered a major limitation to mass screening with MRI. PURPOSE: To perform a cost-benefit analysis of a simulated breast cancer screening program for average-risk women comparing MRI with mammography. STUDY TYPE: Population simulation study. POPULATION/SUBJECTS: Five million (M) hypothetical women undergoing breast cancer screening. FIELD STRENGTH/SEQUENCE: Simulation based primarily on Kuhl et al8 study utilizing 1.5T MRI with an axial bilateral 2D multisection gradient-echo dynamic series (repetition time / echo time 250/4.6 msec; flip angle, 90°) with a full 512 × 512 acquisition matrix and a sensitivity encoding factor of two, performed prior to and four times after bolus injection of 0.1 mmol of gadobutrol per kg of body weight (Gadovist; Bayer, Germany). An axial T2 -weighted fast spin-echo sequence with identical anatomic parameters was also included. ASSESSMENT: A Monte Carlo simulation utilizing Medicare reimbursement rates to calculate input variable costs was developed to compare 5M women undergoing breast cancer screening with either triennial MRI or annual mammography, 2.5M in each group, over 30 years. STATISTICAL TESTS: Expected recall rates, BI-RADS 3, BI-RADS 4/5 cases and cancer detection rates were determined from published literature with calculated aggregate costs including resultant diagnostic/follow-up imaging and biopsies. RESULTS: Baseline screening of 2.5M women with breast MRI cost $1.6 billion (B), 3× higher than baseline mammography screening ($0.54B). With subsequent screening, MRI screening is more cost-effective than mammography screening in 24 years ($13.02B vs. $13.03B). MRI screening program costs are largely driven by cost per MRI exam ($549.71). A second simulation model was performed based on MRI Medicare reimbursement trends using a lower MRI cost ($400). This yielded a cost-effective benefit compared to mammography screening in less than 6 years ($3.41B vs. $3.65B), with over a 22% cost reduction relative to mammography screening in 12 years and reaching a 38% reduction in 30 years. DATA CONCLUSION: Despite higher initial cost of a breast MRI screening program for average-risk women, there is ultimately a cost savings over time compared with mammography. This estimate is conservative given cost-benefit of additional/earlier breast cancers detected by breast MRI were not accounted for. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 6 J. Magn. Reson. Imaging 2019.

Establishment of the first International Standard for human anti-typhoid capsular Vi polysaccharide IgG.

Vi capsular polysaccharide (Vi) conjugate vaccines, which can prevent typhoid in infants and young children, are being developed. Comparative immunogenicity studies are facilitated by an International Standard (IS) for human anti-Vi IgG. 16/138, a pool of sera from volunteers which received either Vi conjugate vaccine or plain Vi vaccine, was assessed as an IS alongside U.S. reference reagent Vi-IgGR1, 2011. Samples were tested in a commercial ELISA (n = 7), a standardised ELISA based on biotinylated Vi (n = 7) and in-house ELISAs (n = 7). Valid estimates were obtained for the potency of all samples in the commercial ELISA, and the commutability of 16/138 and Vi-IgGR1, 2011 was evident for the commercial ELISA and in-house ELISAs based on a coating of Vi and protein. The WHO Expert Committee on Biological Standardization established 16/138 as the first IS for anti-Vi IgG with 100 IU per ampoule and assigned 163 IU per vial of Vi-IgGR1, 2011.

Fish, Fish Oils and Cardioprotection: Promise or Fish Tale?

Fish and commercially available fish oil preparations are rich sources of long-chain omega-3 polyunsaturated fatty acids. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important fatty acids in fish oil. Following dietary intake, these fatty acids get incorporated into the cell membrane phospholipids throughout the body, especially in the heart and brain. They play an important role in early brain development during infancy, and have also been shown to be of benefit in dementia, depression, and other neuropsychiatric disorders. Early epidemiologic studies show an inverse relationship between fish consumption and the risk of coronary heart disease. This led to the identification of the cardioprotective role of these marine-derived fatty acids. Many experimental studies and some clinical trials have documented the benefits of fish oil supplementation in decreasing the incidence and progression of atherosclerosis, myocardial infarction, heart failure, arrhythmias, and stroke. Possible mechanisms include reduction in triglycerides, alteration in membrane fluidity, modulation of cardiac ion channels, and anti-inflammatory, anti-thrombotic, and anti-arrhythmic effects. Fish oil supplements are generally safe, and the risk of toxicity with methylmercury, an environmental toxin found in fish, is minimal. Current guidelines recommend the consumption of either one to two servings of oily fish per week or daily fish oil supplements (around 1 g of omega-3 polyunsaturated fatty acids per day) in adults. However, recent large-scale studies have failed to demonstrate any benefit of fish oil supplements on cardiovascular outcomes and mortality. Here, we review the different trials that evaluated the role of fish oil in cardiovascular diseases.

Dislocation rates following primary total hip arthroplasty have plateaued in the Medicare population.

The purpose of this study was to determine if the use of larger femoral head diameters, in combination with recent practice including enhanced soft tissue choices and various operative exposure choices has led to any further decline in dislocation rates. 51,901 patients undergoing primary THA were identified from 5% Medicare Part B (physician/carrier) claims between January 1, 1997 and December 31, 2011. Dislocation rate at 6 months following THA was 2.84% over the study period (1997-2011). From 2005 to 2011, dislocation rates following primary THA have plateaued in the United States at approximately 2%. This suggests that the full benefits using large femoral head sizes are now realized. For further improvement in dislocation rates, a greater emphasis will be required on patient selection, surgical technique and component alignment.

Fully automated tool to identify the aorta and compute flow using phase-contrast MRI: validation and application in a large population based study.

PURPOSE: To assess if fully automated localization of the aorta can be achieved using phase contrast (PC) MR images. MATERIALS AND METHODS: PC cardiac-gated MR images were obtained as part of a large population-based study. A fully automated process using the Hough transform was developed to localize the ascending aorta (AAo) and descending aorta (DAo). The study was designed to validate this technique by determining: (i) its performance in localizing the AAo and DAo; (ii) its accuracy in generating AAo flow volume and DAo flow volume; and (iii) its robustness on studies with pathological abnormalities or imaging artifacts. RESULTS: The algorithm was applied successfully on 1884 participants. In the randomly selected 50-study validation set, linear regression shows an excellent correlation between the automated (A) and manual (M) methods for AAo flow (r = 0.99) and DAo flow (r = 0.99). Bland-Altman difference analysis demonstrates strong agreement with minimal bias for: AAo flow (mean difference [A-M] = 0.47 ± 2.53 mL), and DAo flow (mean difference [A-M] = 1.74 ± 2.47 mL). CONCLUSION: A robust fully automated tool to localize the aorta and provide flow volume measurements on phase contrast MRI was validated on a large population-based study.

Cardiovascular outcome associations among cardiovascular magnetic resonance measures of arterial stiffness: the Dallas heart study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) has been validated for the noninvasive assessment of total arterial compliance and aortic stiffness, but their associations with cardiovascular outcomes is unknown. The purpose of this study was to evaluate associations of CMR measures of total arterial compliance and two CMR measures of aortic stiffness with respect to future cardiovascular events. METHODS: The study consisted of 2122 Dallas Heart Study participants without cardiovascular disease who underwent CMR at 1.5 Tesla. Aortic stiffness was measured by CMR-derived ascending aortic distensibility and aortic arch pulse wave velocity. Total arterial compliance was calculated by dividing left ventricular stroke volume by pulse pressure. Participants were monitored for cardiovascular death, non-fatal cardiac events, and non-fatal extra-cardiac vascular events over 7.8 ± 1.5 years. Cox proportional hazards regression was used to assess for associations between CMR measures and cardiovascular events. RESULTS: Age, systolic blood pressure, and resting heart rate were independently associated with changes in ascending aortic distensibility, arch pulse wave velocity, and total arterial compliance (all p < .0001). A total of 153 participants (6.9%) experienced a cardiovascular event. After adjusting for traditional risk factors, total arterial compliance was modestly associated with increased risk for composite events (HR 1.07 per 1SD, p = 0.03) while the association between ascending aortic distensibility and composite events trended towards significance (HR 1.18 per 1SD, p = 0.08). Total arterial compliance and aortic distensibility were independently associated with nonfatal cardiac events (HR 1.11 per 1SD, p = 0.001 and HR 1.45 per 1SD, p = 0.0005, respectively), but not with cardiovascular death or nonfatal extra-cardiac vascular events. Arch pulse wave velocity was independently associated with nonfatal extra-cardiac vascular events (HR 1.18 per 1SD, p = 0.04) but not with cardiovascular death or nonfatal cardiac events. CONCLUSIONS: In a multiethnic population free of cardiovascular disease, CMR measures of arterial stiffness are associated with future cardiovascular events. Total arterial compliance and aortic distensibility may be stronger predictors of nonfatal cardiac events, while pulse wave velocity may be a stronger predictor of nonfatal extra-cardiac vascular events.

Test Retest Reproducibility of Organ Volume Measurements in ADPKD Using 3D Multimodality Deep Learning.

RATIONALE AND OBJECTIVES: Following autosomal dominant polycystic kidney disease (ADPKD) progression by measuring organ volumes requires low measurement variability. The objective of this study is to reduce organ volume measurement variability on MRI of ADPKD patients by utilizing all pulse sequences to obtain multiple measurements which allows outlier analysis to find errors and averaging to reduce variability. MATERIALS AND METHODS: In order to make measurements on multiple pulse sequences practical, a 3D multi-modality multi-class segmentation model based on nnU-net was trained/validated using T1, T2, SSFP, DWI and CT from 413 subjects. Reproducibility was assessed with test-re-test methodology on ADPKD subjects (n = 19) scanned twice within a 3-week interval correcting outliers and averaging the measurements across all sequences. Absolute percent differences in organ volumes were compared to paired students t-test. RESULTS: Dice similarlity coefficient > 97%, Jaccard Index > 0.94, mean surface distance < 1 mm and mean Hausdorff Distance < 2 cm for all three organs and all five sequences were found on internal (n = 25), external (n = 37) and test-re-test reproducibility assessment (38 scans in 19 subjects). When averaging volumes measured from five MRI sequences, the model automatically segmented kidneys with test-re-test reproducibility (percent absolute difference between exam 1 and exam 2) of 1.3% which was better than all five expert observers. It reliably stratified ADPKD into Mayo Imaging Classification (area under the curve=100%) compared to radiologist. CONCLUSION: 3D deep learning measures organ volumes on five MRI sequences leveraging the power of outlier analysis and averaging to achieve 1.3% total kidney test-re-test reproducibility.