Non-occlusive mesenteric ischaemia (NOMI) with and without reperfusion: CT features useful for diagnosis and their prognostic value

Purpose: NOMI is a dynamic condition. Its appearance at imaging may be different depending on the time in which CT examination is performed and on the presence of reperfusion event. The aim of our work has been to assess the efficacy of MDCT for the diagnosis of NOMI, with and without reperfusion event. Methods and Materials: Clinical and imaging data from 20 patients (16 males, 4 females) with a dismissal summary of NOMI were retrospectively reviewed. All patients had at least 1 abdominal MDCT examination (n=28) followed by surgery (n=8), autopsy (n=2), angiography (n=1) or endoscopy (n=9). The CT scans were evaluated for evidence of vessels, mesentery, bowel and cavity features. The mean diameter of the SMA of NOMI cases were compared with that of 30 controlled cases. Results: The average SMA diameter of NOMI cases were statistically smaller than that of controls (K-S test: D=0.75, Prob=3.7E‑08). A correlation between the reperfusion event and mesenteric fat stranding (p=0.026), bowel wall thickening (p=3.2E‑05) and high attenuation of the bowel wall on unenhanced CT images (p=2.8E‑04) was demonstrated by Fisher’s exact tests. Normal mesenteric vessels plus wall thickening was significantly correlated with lower mortality (p= 0.034). Conclusion: The evaluation of mesentery, bowel and peritoneal CT features, in addition to the vessel findings will supply additional information to recognise NOMI and in discriminating the presence of a reperfusion event.