小肠间质瘤CT表现及不同危险性征象分析

目的 探讨小肠间质瘤的CT表现特点及不同危险性CT征象.方法 回顾性观察25例经手术病理证实的小肠间质瘤CT资料,并与手术及病理所见相对照;分析依据病理组织学分级的不同危险性组别的CT征象,并对其差别进行x2检验.结果 肿瘤起源于空肠9例,回肠13例,十二指肠3例.黏膜下型2例,肌壁间型13例,浆膜下型10例.病理分型:高危12例,中危7例,低危5例,极低危1例.典型CT表现为形态不规则或类圆形软组织肿块,多外向性生长,边界清楚,密度不均匀,与病理对照为坏死囊变、黏液变性及空洞或窦道形成.肠系膜脂肪受侵呈点索状高密度.增强扫描多明显强化,动静脉期强化峰值变化不大.小肠间质瘤以5 cm为界的大小、形态是否规则、密度是否均匀、强化动脉期有无血管样影,在不同危险性组别(极低危及低危险组与中高危险组)中差异有统计学意义(P＜0.05);强化程度差异无统计学意义(P＞0.05).结论 小肠间质瘤CT表现有一定的特点;不同危险性肿瘤的某些CT征象有差异性,中高危险性多表现为直径大于5 cm、密度不均匀、形态不规则、见血管样强化.

Analysis of CT manifestations and different risk groups CT findings of small intestinal stromal tumor

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.