Portal vein aneurysm-etiology,multimodal imaging and current management

Portal vein aneurysm(PVA)is a rare vascular abnormality,representing 3%of all venous aneurysms in the human body,and is not well understood.It can be congenital or acquired,located mainly at the level of confluence,main trunk,branches and bifurcation.A PVA as an abnormality of the portal venous system was first reported in 1956 by Barzilai and Kleckner.A review from 2015 entitled“Portal vein aneurysm:What to know”considered fewer than 200 cases.In the last seven years,there has been an increase in the number of PVAs diagnosed thanks to routine abdominal imaging.The aim of this review is to provide a comprehensive update of PVA,including aetiology,epidemiology,and clinical assessment,along with an evaluation of advanced multimodal imaging features of aneurysm and management approaches.

Current status of deep learning in abdominal image reconstruction

Abdominal magnetic resonance imaging(MRI)and computed tomography(CT)are commonly used for disease screening,diagnosis,and treatment guidance.However,abdominal MRI has disadvantages including slow speed and vulnerability to motions,while CT suffers from problems of radiation.It has been reported that deep learning reconstruction can solve such problems while maintaining good image quality.Recently,deep learning-based image reconstruction has become a hot topic in the field of medical imaging.This study reviews the latest research on deep learning reconstruction in abdominal imaging,including the widely used convolutional neural network,generative adversarial network,and recurrent neural network.

COVID-19 and the digestive system:A comprehensive review

The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)is spreading at an alarming rate,and it has created an unprecedented health emergency threatening tens of millions of people worldwide.Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smearnegative respiratory samples.However,demonstration of confirmed fecal-oral transmission has been difficult.Clinical studies have shown an incidence rate of gastrointestinal(GI)symptoms ranging from 2%to 79.1%in patients with COVID-19.They may precede or accompany respiratory symptoms.The most common GI symptoms included nausea,diarrhea,and abdominal pain.In addition,some patients also had liver injury,pancreatic damage,and even acute mesenteric ischemia/thrombosis.Although the incidence rates reported in different centers were quite different,the digestive system was the clinical component of the COVID-19 section.Studies have shown that angiotensinconverting enzyme 2,the receptor of SARS-CoV-2,was not only expressed in the lungs,but also in the upper esophagus,small intestine,liver,and colon.The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells,dysregulation of angiotensin-converting enzyme 2,immune-mediated tissue injury,and gut dysbiosis caused by microbiota.Additionally,numerous experiences,guidelines,recommendations,and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients,inpatients,and endoscopy in the era of COVID-19.In this review,based on our previous work and relevant literature,we mainly discuss potential fecal-oral transmission,GI manifestations,abdominal imaging findings,relevant pathophysiological mechanisms,and infection control and prevention measures in the time of COVID-19.

Contrast-enhanced Ultrasound in Detecting Endoleaks with Failed Computed Tomography Angiography Diagnosis after Endovascular Abdominal Aortic Aneurysm Repair

Background： Endovascular aneurysnl repair （EVAR） is one of the first-line therapies of abdominal aortic aneurysms. Postoperative endoleak is the most common complication of EVAR. Computed tomography angiography （CTA）, which is routine for follow-up, has side effects （e.g., radiation） and also has a certain percentage of missed diagnosis. Preliminary studies on contrast-enhanced ultrasound （CEUS） have shown that the sensitivity of CEUS for detecting endoleak is no lower than that of CTA. To investigate the advantages of CEUS, we conducted CEUS examinations of post-EVAR cases in which CTA failed to detect endoleak or could not verify the type of endoleak. Methods： Post-EVAR patients, who were clinically considered to have endoleak and met the inclusion criteria were enrolled between March 2013 and November 2014. All of the patients underwent color Doppler flow imaging （CDFI） and a CEUS examination. Size, location, microbubble dispersion, and hemodynamic characteristics of leaks were recorded. Comparison between the diagnosis of CEUS and CDF1 was conducted using Fisher＇s exact test and clinical outcomes of all patients were followed up. Results： Sixteen patients were enrolled, and 12 （75%） had endoleaks with verified types by CEUS. Among 12 cases of endoleaks were positive by CEUS, 10 were CDFl-positive, and the four CEUS-negative cases were all negative by CDFI. The diagnostic values of CEUS and CDFI were statistically difl＇erent （P = 0,008）. Six patients with high-pressure endoleaks received endovascular re-intervention guided by CEUS results. One patient with type Ⅲ endoleak had open surgery when endovascular repair failed. Conclusions： C EUS is a new, safe, and effective means for detection ofendoleaks post-EVAR. This technique can be used as a supplement for routine CTA follow-up to provide more detailed information on endoleak and its category.