Background The association of pulmonary embolism (PE) with deep vein thrombosis (DVT) in patients with coronavirus disease 2019 (COVID-19) remains unclear, and the diagnostic accuracy of D -dimer tests for PE is unknown. Purpose To conduct meta-analysis of the study-level incidence of PE and DVT and to evaluate the diagnostic accuracy of D -dimer tests for PE from multicenter individual patient data. Materials and Methods A systematic literature search identified studies evaluating the incidence of PE or DVT in patients with COVID-19 from January 1, 2020, to June 15, 2020. These outcomes were pooled using a random-effects model and were further evaluated using metaregression analysis. The diagnostic accuracy of D -dimer tests for PE was estimated on the basis of individual patient data using the summary receiver operating characteristic curve. Results Twenty-seven studies with 3342 patients with COVID-19 were included in the analysis. The pooled incidence rates of PE and DVT were 16.5% (95% CI: 11.6, 22.9; I 2 = 0.93) and 14.8% (95% CI: 8.5, 24.5; I 2 = 0.94), respectively. PE was more frequently found in patients who were admitted to the intensive care unit (ICU) (24.7% [95% CI: 18.6, 32.1] vs 10.5% [95% CI: 5.1, 20.2] in those not admitted to the ICU) and in studies with universal screening using CT pulmonary angiography. DVT was present in 42.4% of patients with PE. D -dimer tests had an area under the receiver operating characteristic curve of 0.737 for PE, and D -dimer levels of 500 and 1000 μg/L showed high sensitivity (96% and 91%, respectively) but low specificity (10% and 24%, respectively). Conclusion Pulmonary embolism (PE) and deep vein thrombosis (DVT) occurred in 16.5% and 14.8% of patients with coronavirus disease 2019 (COVID-19), respectively, and more than half of patients with PE lacked DVT. The cutoffs of D -dimer levels used to exclude PE in preexisting guidelines seem applicable to patients with COVID-19. © RSNA, 2020 Supplemental material is available for this article. See also the editorial by Woodard in this issue.

Hepatocellular carcinoma (HCC) is a major health concern, and early HCC diagnosis is a primary radiological concern. The goal of imaging liver cirrhosis is the early identification of high-grade dysplastic nodules/early HCC since their treatment is associated with a higher chance of radical cure and lower recurrence rates. The newly introduced MRI contrast agent gadoxetic acid (gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, Gd-EOB-DTPA) has enabled the concurrent assessment of tumor vascularity and hepatocyte-specific contrast enhancement during the hepatobiliary phase (HBP), which can help to detect and characterize smaller HCCs and their precursors. HBP-EOB-MRI identifies hypovascular HCC nodules that are difficult to detect using ultrasonography or computed tomography, which do not show the diagnostic HCC hallmarks of arterial washin and portal/delayed washout. During the HBP, typical HCC and early HCC appear hypointense on EOB-MRI, whereas low-grade dysplastic or regenerative nodules appear as iso- or hyperintense lesions. The diagnostic accuracy of EOB-MRI for the diagnosis of early HCC is approximately 95-100%. One third of hypovascular hypointense nodules in HBP become hypervascular ‘progressed' HCC, with a 1- and 3-year cumulative incidence of 25 and 41%, respectively. Therefore, these hypovascular nodules should be strictly followed up or definitely treated as typical HCC. Due to this capability of identifying the precursors and biological behavior of HCC, EOB-MRI has rapidly become a key imaging tool for the diagnosis of HCC and its precursors, despite the scarce MRI availability throughout Europe. With increasing experience, EOB-MRI may eventually be established as the diagnostic imaging modality of choice in this setting. Full recognition by the Western EASL-AASLD guidelines is expected.

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. Tumor resection is the treatment of choice for localized disease. Tyrosine kinase inhibitors (imatinib, sunitinib) are the standard therapy for metastatic or unresectable GISTs. GISTs usually metastasize to the liver and peritoneum. Bone metastases are uncommon. We describe three cases of bone metastases in patients with advanced GISTs: two women (82 and 54 years of age), and one man (62 years of age). Bones metastases involved the spine, pelvis and ribs in one patient, multiple vertebral bodies and pelvis in one, and the spine and iliac wings in the third case. The lesions presented a lytic pattern in all cases. Two patients presented with multiple bone metastases at the time of initial diagnosis and one patient after seven years during the follow-up period. This report describes the diagnosis and treatment of the lesions and may help clinicians to manage bones metastases in GIST patients.

AIM To report the severity and extent of pulmonary thromboembolic disease (PTD) in COVID-19 patients undergoing computed tomography pulmonary angiography (CTPA) in a tertiary centre. MATERIALS AND METHODS This is a retrospective analysis of COVID-19 patients undergoing CTPA over a period of 27 days. The presence, extent, and severity of PTD were documented. Two observers scored the pattern and extent of lung parenchymal disease including potential fibrotic features, as well as lymph node enlargement and pleural effusions. Consensus was achieved via a third observer. Interobserver agreement was assessed using kappa statistics. Student's t -test, chi-squared, and Mann–Whitney U -tests were used to compare imaging features between PTD and non-PTD sub-groups. RESULTS During the study period, 100 patients with confirmed COVID-19 underwent CTPA imaging. Ninety-three studies were analysed, excluding indeterminate CTPA examinations. Overall incidence of PTD was 41/93 (44%) with 28/93 patients showing small vessel PTD (30%). D-dimer was elevated in 90/93 (96.8%) cases. A high Wells' score did not differentiate between PTD and non-PTD groups ( p= 0.801). The interobserver agreement was fair (kappa=0.659) for parenchymal patterns and excellent (kappa=0.816) for severity. Thirty-four of the 93 cases (36.6%) had lymph node enlargement; 29/34 (85.3%) showed no additional source of infection. Sixteen of the 93 (17.2%) cases had potential fibrotic features. CONCLUSION There is a high incidence of PTD in COVID-19 patients undergoing CTPA and lack of a risk stratification tool. The present data indicates a higher suspicion of PTD is needed in severe COVID-19 patients. The concomitant presence of possible fibrotic features on CT indicates the need for follow-up.