胃神经鞘瘤和间质瘤的多排CT表现及对照研究

Imaging findings and a comparative study of gastric schwannomas and gastric stromal tumors on multi-slice CT

目的:探讨胃神经鞘瘤(GS)的CT表现,并与胃间质瘤(GST)进行对照分析,以提高诊断正确率。材料与方法:选取经手术病理证实的GS 19例及GST 76例,回顾性分析其临床特征及CT表现,并对两者的CT表现进行比较。CT影像资料由两名具有丰富经验的高年资放射科医师评估,评估内容包括肿瘤大小、形态、生长方式、增强模式、强化程度、肿瘤内部出血、钙化及坏死囊变。统计学分析采用单因素方差分析、LSD检验和卡方检验。结果:极低风险度GST的最大直径小于GS(P=0.04),低、中风险度间质瘤最大直径与胃肠道神经鞘瘤的最大直径没有统计学意义(P=0.98,P=0.23),高风险度间质瘤的最大直径大于GS(P=0.01)。GS(18/19)和极低(16/16)、低风险(28/34)及中风险(11/13)GST多呈圆形或卵圆形,而高风险GST(8/13)多呈分叶状或不规则形。极低风险GST腔内生长较多见(12/16)。GS(18/19)和极低危险度(15/16)GST肿瘤内部均匀强化。低(26/34)、中等(11/13)及高危险度GST(13/13)中等或明显强化较GS(9/19)多见。GS(1/18)内部的坏死囊变较低(11/34)、中等(6/13)及高危险度(11/13)间质瘤少见(P=0.01)。结论:胃肠道神经鞘瘤CT上多表现为圆形、卵圆形的肿块,增强后呈轻度均匀强化,肿瘤内部坏死囊变、钙化、出血现象较少见,与高危险度GST影像学表现差异较大,但与极低、低、中危险度GST较难区别。

Objective： To investigate CT findings of gastrointestinal schwannomas（GS） and gastric stromal tumors（GST）, and further to compare their CT features in order to differentiate GS from GST. Materials and Methods： 19 GSs and 76 GSTs proven surgically and pathologically were enrolled in this study. Two experienced radiologists retrospectively evaluated and compared the CT features including size, contour, growth pattern, pattern and degree of contrast enhancement, and the pres- ence of intralesional low attenuation area, hemorrhage and calcification. The statistical significance was evaluated by using 95% confidence interval, one-way ANOVA, LSD test and Chi-Square test. Results： As the diameter was concerned, GSs were significantly bigger than GSTs at very low risk（P=0.04）, and smaller than GSTs at high risk（P=0.01）. The contour was round or oval in most GSs（18/19）, GSTs at very low risk（16/16）, GSTs at low risk（28/34） and GSTs at intermediate risk（11/13）, but lob- ulated in GSTs at high risk（8/13）. GSTs at very low risk frequently demonstrated an endoluminal growth pattern（12/16）, while a homogeneous enhancement pattern was frequently found in GSs（18/19） and GSTs at very low risk（15/16）. Good enhancement degree was more common in GSTs at low risk（26/34）, GSTs at intermediate risk（11/13） and GSTs at high risk（13/13） than in GSs（9/19）. The intralesional low attenuation area was more common in GSTs at low risk（11/34）, GSTs at intermediate risk（6/ 13） and GSTs at high risk（11/13） than in GSs（1/18）. Conclusion： GSs frequently show a round or oval appearance with slight homogeneous enhancement pattern and rare intralesional necrosis, hemorrhage or calcification. These CT findings are common in GSTs at very low risk, low risk and intermediate risk, but distinguishable from GSTs at high risk.