Spontaneous isolated dissection of the superior mesenteric artery:multi-slice computed tomographic angiography findings in seven cases

Objective:To assess the value of multi-slice computed tomographic angiography(MSCTA) in the diagnosis of spontaneous isolated dissection of superior mesenteric artery(SMA).Methods:7 patients with clinically suspected acute mesenteric ischemia underwent MSCTA.Multiplanar and three-dimensional images were obtained by imaging postprocessing techniques including volume rendering technique(VRT),multiplanar reconstruction(MPR),curved planar reformation(CPR) and maximum intensity projection(MIP) on a workstation.Image reading was performed in consensus by two experienced cardiovascular radiologists.Results:According to Yun's classification,there were one case of typeⅠ,three type Ⅱa,two type Ⅱb and one type Ⅲ.Spontaneous isolated dissection of SMA displays the same MSCTA features as aortic dissection.Intimal flaps were seen in five patients,with intimal tears at the proximal SMA.Other MSCTA findings associated with spontaneous isolated dissection of SMA were enlarged diameter of the SMA(n=2),increased attenuation of the fat around the SMA(n=2),local ileum wall thickening due to edema(n=2),dilated ascending colon(n=1) and hemorrhagic ascites(n=2).Conclusion:MSCTA allows the comprehensive evaluation of spontaneous isolated dissection of the SMA in terms of morphologic features and extent,making it the first-line imaging modality for the evaluation of spontaneous isolated dissection of the SMA.