Background Patients hospitalised with COVID-19 are at risk for thrombotic events after discharge; the role of extended thromboprophylaxis in this population is unknown. Methods In this open-label, multicentre, randomised trial conducted at 14 centres in Brazil, patients hospitalised with COVID-19 at increased risk for venous thromboembolism (International Medical Prevention Registry on Venous Thromboembolism [IMPROVE] venous thromboembolism [VTE] score of ≥4 or 2–3 with a D-dimer >500 ng/mL) were randomly assigned (1:1) to receive, at hospital discharge, rivaroxaban 10 mg/day or no anticoagulation for 35 days. The primary efficacy outcome in an intention-to-treat analysis was a composite of symptomatic or fatal venous thromboembolism, asymptomatic venous thromboembolism on bilateral lower-limb venous ultrasound and CT pulmonary angiogram, symptomatic arterial thromboembolism, and cardiovascular death at day 35. Adjudication was blinded. The primary safety outcome was major bleeding. The primary and safety analyses were carried out in the intention-to-treat population. This trial is registered at ClinicalTrials.gov , NCT04662684 . Findings From Oct 8, 2020, to June 29, 2021, 997 patients were screened. Of these patients, 677 did not meet eligibility criteria; the remaining 320 patients were enrolled and randomly assigned to receive rivaroxaban (n=160 [50%]) or no anticoagulation (n=160 [50%]). All patients received thromboprophylaxis with standard doses of heparin during hospitalisation. 165 (52%) patients were in the intensive care unit while hospitalised. 197 (62%) patients had an IMPROVE score of 2–3 and elevated D-dimer levels and 121 (38%) had a score of 4 or more. Two patients (one in each group) were lost to follow-up due to withdrawal of consent and not included in the intention-to-treat primary analysis. The primary efficacy outcome occurred in five (3%) of 159 patients assigned to rivaroxaban and 15 (9%) of 159 patients assigned to no anticoagulation (relative risk 0·33, 95% CI 0·12–0·90; p=0·0293). No major bleeding occurred in either study group. Allergic reactions occurred in two (1%) patients in the rivaroxaban group. Interpretation In patients at high risk discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days improved clinical outcomes compared with no extended thromboprophylaxis. Funding Bayer.

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Background Evaluation of interobserver agreement of the PI‐RADS v2 lexicon is important to validate the uniformity of this widely used classification. Purpose To determine the interobserver agreement of PI‐RADS v2 lexicon among eight radiologists with varying levels of experience. Study Type Retrospective. Population In all, 160 consecutively imaged men with confirmatory targeted biopsy. Field Strength/Sequence 3T scanner without an endorectal coil. T2‐weighted imaging (T2w), diffusion‐weighted imaging (DWI), apparent diffusion coefficient (ADC) map and dynamic contrast‐enhanced sequence were performed. Assessment Eight radiologists (two highly experienced, two moderately experienced, and four less experienced) independently read 130 lesions in the peripheral zone (PZ) and 30 lesions in the transition zone (TZ), blinded to clinical MRI indication and biopsy results. The features described in PI‐RADS v2 for TZ and PZ lesions were evaluated. Statistical Tests Conger's kappa, percentage of concordance, and first‐order agreement coefficient (AC1) were used to evaluate interobserver agreement. Results From the features evaluated on PZ lesions, definite extraprostatic extension (EPE) / invasive behavior on T2w had good agreement (AC1 = 0.80), and the others had fair agreement (AC1 = 0.32–0.40). From the features evaluated on TZ lesions, two had good agreement: definite EPE/invasive behavior (AC1 = 0.77) and moderate/marked hypointensity (AC1 = 0.67) on T2w. Encapsulation and lenticular shape on T2w, focal (not indistinct) on DWI and ADC map, and marked hypointensity on ADC map (AC1 = 0.45 to 0.60) had moderate agreement, whereas heterogeneous and circumscribed (not obscured margins) on T2w, marked hyperintensity on high‐b‐value DWI, and the presence or not of early enhancement in the lesion/region of the lesion (AC1 = 0.30 to 0.38) had fair agreement. Data Conclusion Interobserver agreement in PI‐RADS v2 lexicon ranges from fair to good among radiologists and improves with increasing experience. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:593–602.

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The objective was to demonstrate the ability of ultrasound (US) with 3D properties to evaluate volumetry and biomechanical parameters of the aorta in patients with and without abdominal aortic aneurysm (AAA). Thirty-one patients with normal aortas (group 1), 46 patients with AAA measuring 3.0-5.5 cm (group 2) and 31 patients with AAA ⩾ 5.5 cm (group 3) underwent a 2D/3D-US examination of the infra-renal aorta, and the images were post-processed prior to being analyzed. In the maximum diameter, the global circumferential strain and the global maximum rotation assessed by 2D speckle-tracking algorithms were compared among the three groups. The volumetry data obtained using 3D-US from 40 AAA patients were compared with the volumetry data obtained by a contemporary computed tomography (CT) scan. The median global circumferential strain was 2.0% (interquartile range (IR): 1.0-3.0), 1.0% (IR: 1.0-2.0) and 1.0% (IR: 1.0-1.75) in groups 1, 2 and 3, respectively (p < 0.001). The median global maximum rotation decreased progressively from group 1 to group 3 (1.38º (IR: 0.77-2.13), 0.80º (IR: 0.57-1.0) and 0.50º (IR: 0.31-0.75), p < 0.001). AAA volume estimations by 3D-US correlated well with CT (R 2 = 0.76). In conclusion, US with 3D properties is non-invasive and has the potential to evaluate volumetry and biomechanical characteristics of AAA.