Objective To investigate the CT features and different risk CT findings of intestinal stromal tumor. Methods The CT imaging data of 25 cases of intestinal stromal tumor confirmed by pathology and compared with operative and pathologic findings were retrospectively studied. Analyzing the CT features based on Histopathologieal classification of the different risk groups and using chi-square test to compare the differences. Results There were 9 cases which tumors originated from the jejunum, and 13 cases from ileum, only 3 cases from duodenum. Among them, 2 cases were submucosal type, 13 cases were intramural type, and 10 cases were subserous type. The pathologic patterns of different risk which included high-risk, intermediated-risk, low-risk, and very low-risk were 12 cases, 7 cases, 5 cases and 1 cases respectively. A typical CT manifestations of intestinal stromal tumors were a outward growth of irregular or round soft tissue mass originated in small intestine which had clear boundary and the non-homogeneous density, which corresponding to necrosis, cystic change, mucoid degeneration and sinus or cavity. Mesenteric fat invaded by tumor showed high-density lines or points shape. The Enhancement of lesion was obvious and not homogeneous which showed little change in peak of enhancement between arterial phase and venous phase. Intestinal stromal tumors took 5 cm as the boundary which including different size, shape, density, and appearance vessel-like artery shadow at arterial phase between different risk groups(low, very low-risk group and intermediated, high-risk group) were statistically different (P ＜0.05), while enhanced degree without significant difference (P ＞ 0.05). Conclusion CT findings of small intestine stromal tumor have characteristics and CT features have significant difference between different risk groups. These features of more than 5 cm in diameter, non-homogeneous density, irregular shape and chaos appearance like vascular enhancement are showed in intermediated-high-risk group.

Objective To detect changes of regional grey matter and white matter volume in patients of neuromyelitis optica (NMO) by voxel-based morphometry (VBM),and investigate its relationship with clinical variables.Methods Conventional magnetic resonance imaging (MRI) and structural threedimensional MRI were obtained from 20 NMO and 20 sex-and age-matched healthy volunteers.The comparison of grey matter and white matter volume between the two groups was analyzed by VBM tools of statistical parametric mapping (SPM) 5.Pearson correlational analysis was used to assess correlations between regional volume decrease and disease duration and expanded disability status scale (EDSS) scores in NMO patients.Results Compared with normal controls,NMO patients had grey matter atrophy in several cortical regions,such as right inferior frontal gyrus (cluster size 514),left superior temporal gyrus (282),right middle temporal gyvus (229) and right insula (211) (t =3.58-5.11,AlphaSim corrected,P ＜0.05).White matter atrophy was found in several subcortical regions in NMO patients,such as right precentral and postcentral gyrus (cluster size 457,110),left middle frontal gyrus (285),and right inferior parietal lobule (231) (t =2.90-4.25,AlphaSim corrected,P ＜ 0.05).Grey matter and white matter volume loss were not significantly correlated with clinical duration or EDSS score in NMO.Conclusion By means of VBM,regional atrophy of grey matter and white matter is found in NMO patients,which may provide evidence for brain structural abnormality in NMO.