能谱CT参数对胃肠道间质瘤危险度分级的初步研究

目的：评价能谱CT参数对胃肠道间质瘤(GIST)危险度分级的价值。方法收集GIST患者41例,其中高危险度13例、中危险度12例、低危险度11例、极低危险度5例,行平扫和三期增强能谱CT扫描,分别在单能量和碘(水)基物质分离图像上定量分析CT值、能谱曲线斜率及碘(水)浓度,并分析其与不同危险度 GIST的相关性。结果①70 keVCT值：动脉期与 GIST危险度呈负相关(r=-0.173)；延迟期与GIST危险度呈正相关(r=0.552)；静脉期与GIST危险度无相关性。②能谱曲线斜率：延迟期不同危险度 GIST的能谱曲线斜率有统计学差异(χ2=6.641,P=0.036)。③标准化碘浓度(NIC)：增强三期各危险度的 NIC值均有统计学差异(F=3.646、χ2=6.046、F=57.233,P=0.035、P=0.049、P<0.001),且延迟期NIC值与GIST危险度有相关性(r=-0.564)。结论

A preliminary study of spectral CT parameters in gastrointestinal stromal tumor risk classification

Objective To evaluate the value of spectral CT in risk classification of gastrointestinal stromal tumor (GIST).Methods Forty-one patients with GIST were collected,including 1 3 in high risk,1 2 in medium risk,1 1 in low risk and 5 in very low risk. All of the patients underwent plain and triple phases contrast enhanced CT with spectral CT scanning mode.CT value of 70 keV monochromatic images,the slope of spectral curve and normalized iodine concentration (NIC)were measured and calculated.Then, data was correlated with the risk of GIST.Results ①The CT value of 70 keV monochromatic images was negative correlation in the arterial phase (r=-0.173),positive correlation in delayed phase (r=0.552),and no correlation in venous phase with the risk of GIST.②The slopes of spectral curves in delayed phase were significantly different in GISTs with the different risk (χ2= 6.641,P= 0.036).③The NIC values of GISTs with different risk were significantly different in the triple phases (F=3.646,χ2=6.046,F=57.233,P=0.035, P=0.049,P<0.001),and correlated with the risk of GIST (r=-0.564)in the delayed phase.Conclusion Quantitative paremeters of spectral CT imaging such as the CT value of 70 keV,the slopes of spectral curves and iodine concentration are valuable for the risk classification of GIST,and can be used as a preoperative reference.