Quantitative evaluation of superior mesenteric artery calcification in hemodialysis patients undergoing aortic valve replacement

Quantifying the calcification of abdominal aorta and major side branches with deep learning

AIM

To explore the possibility of a neural network-based method for quantifying calcifications of the abdominal aorta and its branches.

MATERIALS AND METHODS

In total, 58 computed tomography (CT) angiography volumes were selected from a dataset of 609 to represent different stages of sclerosis. The ground truth segmentations of the abdominal aorta, coeliac trunk, superior mesenteric artery, renal arteries, common iliac arteries, and their calcifications were delineated manually. Two V-Net ensemble models were trained, one for segmenting arteries of interest and another for calcifications. The branches of interest were shortened algorithmically. The volumes of calcification were then evaluated from the arteries of interest.

RESULTS

The results indicate that automatic detection is possible with a high correlation to the ground truth. The scores for the ensemble calcification model were dice score of 0.69 and volumetric similarity (VS) of 0.80 and for the arteries of interest segmentations: aorta: dice 0.96, VS 0.98; aortic branches: dice 0.74, VS 0.87; and common iliac arteries: dice 0.72, VS 0.91.

CONCLUSIONS

The presented neural network model is the first to be capable of automatically segmenting, in addition to calcification, both the aorta and its branches from contrast-enhanced CT angiography. This technology shows promise in addressing limitations inherent in earlier methods that relied solely on plain CT.

Large bowel perforation due to cytomegalovirus colitis in a post-cardiac surgical patient on chronic hemodialysis

BACKGROUND

Cytomegalovirus (CMV) colitis with colonic perforation is an exceedingly rare but life-threatening condition. The most comorbid diagnosis in patients with perforated CMV colitis is human immunodeficiency virus in the setting of advanced immunosuppression associated with CD4 < 50 cells/μL.

CASE PRESENTATION

A 75-year-old female with a ≥ 30-year history of hemodialysis presented with progressive dyspnea on exertion. Transthoracic echocardiography showed moderate mitral stenosis and severe aortic stenosis. Although she was a high-risk candidate with a risk for mortality of 17.17% and morbidity and mortality both of 35.63% in The Society of Thoracic Surgeons risk calculator, we performed mitral and aortic valve replacement with both biological valves. Postoperative course was complicated with a high dose of inotropic support, cardiac tamponade requiring open drainage, and the need for a tracheostomy. Abdominal distension was observed, and enhanced computed tomography demonstrated free air and a suspected perforated sigmoid colon. Emergency laparotomy revealed a 20-cm longitudinal perforation in the sigmoid colon. A left hemicolectomy with stoma was performed. Immunostaining of a sample of her colon showed cytomegalovirus-positive cells.

CONCLUSIONS

Cardiac surgeons should consider cytomegalovirus colitis as a differential diagnosis during the course of cardiac surgery even in immunocompetent patients.