Radiologists’ performance in the diagnosis of acute intestinal ischemia, using MDCT and specific CT findings, using a variety of CT protocols

Abstract

The aim of this study was to evaluate the performance of radiologists in the diagnosis of acute intestinal ischemia using specific multi-detector CT findings. The abdominal CT scans of 90 patients were retrospectively reviewed by three radiologists: an abdominal imaging specialist, an experienced general radiologist, and a senior resident. Forty-seven patients had surgically proven intestinal ischemia and comprised the case group, while 43 patients had no evidence of intestinal ischemia at surgery and comprised the control group. Images were reviewed in a random and blinded fashion. Radiologists' performance in diagnosing bowel ischemia from other bowel pathologies was evaluated. The sensitivity, specificity, and accuracy for diagnosing bowel ischemia were 89%, 67%, and 79% for the abdominal imager; 83%, 67%, and 76% for the general radiologist; and 66%, 83%, and 74% for the senior resident, respectively. The calculated kappa value for inter-observer agreement regarding the presence of bowel ischemia was 0.79. CT findings that significantly distinguished bowel ischemia from other bowel pathologies were decreased or absent bowel wall enhancement, filling defect in the superior mesenteric artery, small bowel pneumatosis, and gas in the portal veins or superior mesenteric vein. For most of these signs, there was good inter-observer agreement. Radiologists' performance in diagnosing bowel ischemia is good, but lower than previously reported since a significant amount of cases are evaluated using a suboptimal CT technique. Radiologists' experience and expertise have an important impact on their performance.

Intestinal Ischemia: US-CT findings correlations

“…In Europe US is frequently performed as primary diagnostic technique for patients with non-specific acute abdominal pain or for patients complaining for intestinal disorders to optimize the use of other imaging techniques [17] or to monitor a pathologic condition that does not require immediate surgery [16]. Sonographic evaluation offers a safe, noninvasive alternative to contrast examinations and, in the clinical suspicion of intestinal infarction, the doppler US could represent a useful modality for the evaluation of severe stenosis in the mesenteric arteries [25-29] and for the evaluation of characteristic intestinal wall changes: in fact relationship between bowel wall changes and the severity of ischemia has been suggested [17].…”

“…Sonographic evaluation offers a safe, noninvasive alternative to contrast examinations and, in the clinical suspicion of intestinal infarction, the doppler US could represent a useful modality for the evaluation of severe stenosis in the mesenteric arteries [25-29] and for the evaluation of characteristic intestinal wall changes: in fact relationship between bowel wall changes and the severity of ischemia has been suggested [17]. It should be noted that the assessment potential of this technique is limited if the patient is obese or has an excessive amount of air in the intestinal loops, furthermore, incompliance of patients may limit the accuracy of this imaging modality [30-33]…”

Clinical significance of pneumatosis intestinalis – correlation of MDCT-findings with treatment and outcome

“…The other assessed bowel wall MDCT findings were pathological wall thickening (>3 mm, provided that bowel loops were not collapsed), pathological contrast enhancement of the bowel mucosa and decrease of the physiological, subtle contrast enhancement of the bowel mucosa [10, 26]. The small bowel was considered dilated, whenever the lumen measured >3 cm in diameter.…”

Multidetector CT findings in patients with mesenteric ischaemia following cardiopulmonary bypass surgery

“…This, combined with an ageing patient population with associated increased comorbidities and risk factors, may lead to a rise in the incidence of ischaemic bowel in patients following CPB surgery [3]. Furthermore, definitive radiological diagnosis is known to be difficult in such patients [7]. The most common CT findings lack specificity, whereas the more specific findings are rarely present [8], thus knowledge of such CT findings and their diagnostic value would be beneficial.…”

“…There have been several studies with a small number of patients looking at the multidetector CT features of patients presenting with mesenteric ischaemia [7,9,[13][14][15], but to our knowledge, apart from a small case series [16], there are no studies specifically investigating the CT signs of bowel ischaemia in a post-cardiac surgery cohort. Thus, the aim of our study was to investigate the CT findings following pathologically proven mesenteric ischaemia/infarction in a retrospective group of patients postcardiac bypass surgery and compare this with the known features of acute mesenteric ischaemia.…”