Typical and atypical COVID-19 computed tomography findings

In December 2019 a novel coronavirus,named severe acute respiratory syndrome coronavirus 2 was identified and the disease associated was named coronavirus disease 2019(COVID-19).Fever,cough,myalgia,fatigue associated to dyspnea represent most common clinical symptoms of the disease.The reference standard for diagnosis of severe acute respiratory syndrome coronavirus 2 infection is real time reverse-transcription polymerase chain reaction test applied on respiratory tract specimens.Despite of lower specificity,chest computed tomography(CT),as reported in manifold scientific studies,showed high sensitivity,therefore it may help in the early detection,management and follow-up of COVID-19 pneumonia.Patients affected by COVID-19 pneumonia usually showed on chest CT some typical features,such as:Bilateral ground glass opacities characterized by multilobe involvement with posterior and peripheral distribution;parenchymal consolidations with or without air bronchogram;interlobular septal thickening;crazy paving pattern,represented by interlobular and intralobular septal thickening surrounded by ground-glass opacities;subsegmental pulmonary vessels enlargement(>3 mm).Halo sign,reversed halo sign,cavitation and pleural or pericardial effusion represent some of atypical findings of COVID-19 pneumonia.On the other hand lymphadenopathy’s and bronchiectasis’frequency is unclear,indeed conflicting data emerged in literature.Radiologists play a key role in recognition of high suspicious findings of COVID-19 on chest CT,both typical and atypical ones.Thus,the aim of this review is to illustrate typical and atypical CT findings of COVID-19.

Layered enhancement at magnetic resonance enterography in inflammatory bowel disease: A meta-analysis

BACKGROUND Documentation of disease activity in patients affected by Crohn’s disease(CD)is mandatory in order to manage patients properly.Magnetic resonance imaging(MRI)is considered the reference cross-sectional technique for the assessment of CD activity.Among MRI findings,layered pattern(LP)of contrast enhancement seems to be one of the most significant signs of severe disease activity;however,it has also been associated with chronic disease and mural fibrosis.AIM To systematically evaluate the accuracy of LP of contrast enhancement in the diagnosis of active inflammation in patients with CD.METHODS In February 2019,we searched the MEDLINE and Cochrane Central Register of Controlled Trials databases for studies evaluating the diagnostic accuracy of LP of contrast enhancement on MRI for the detection of active inflammation in patients with CD.To be included,studies had to use histopathologic analysis(endoscopy or surgery)as the reference standard.Risk of bias and applicability concerns of the included studies were evaluated by using items from the Quality Assessment for Diagnostic Accuracy Studies 2(QUADAS-2)tool.Pooled sensitivity and specificity were determined using a bivariate random-effect model.Heterogeneity was quantified by using the I2 statistic.Our meta-analysis received no funding,and the review protocol was not published or registered in advance.RESULTS Of the 1383 studies identified,five articles were finally selected for quantitative and qualitative synthesis(245 patients,238 of whom had histopathologically confirmed CD,144 with active inflammation and 94 with inactive disease).The meta-analysis showed a pooled sensitivity of 49.3%(95%CI:41%-57.8%;I2:90.7%)and specificity of 89.1%(95%CI:81.3%-94.4%;I^2:48.6%).Pooled PLR and NLR were 3.3(95%CI:1.9-5.7;I2:6.1%)and 0.6(95%CI:0.5-0.9;I2 70.5%),respectively.SDOR was 6.8(95%CI:2.6-17.6;I2:27.1%).The summary ROC curve showed an area under the curve(AUC)of 0.82(SE 0.06;Q*0.76).High risk of bias and applicability concerns were observed in the domains of patient selection for one included study.CONCLUSION LP on contrast-enhanced MRI is a specific finding to rule out active inflammation in patients with CD.Further studies using a prespecified definition of LP on contrast-enhanced MRI are needed to support our findings.