摘要
Abstract
Objective:To evaluate the utility of quantitative parameters derived from single-source dual-energy CT(DECT)for noninvasive prediction of high microsatellite instability(MSI-H)status in gastric cancer.Methods:This retrospective study enrolled 123 patients with gastric cancer who underwent preoperative contrast-enhanced DECT.All patients were stratified into MSI-H group(41 cases)and microsatellite stable/low microsatellite instability(MSS/MSI-L)group(82 cases).Spectral imaging parameters were analyzed,including virtual monochromatic image(VMI)CT values at 40-70 keV,spectral curve slope(K40-70),iodine concentration(IC),normalized iodine concentration(NIC),and effective atomic number(Zeff)in plain scan and contrast enhancement.Intergroup differences were compared using independent t-tests.Logistic regression identified independent predictors,while ROC curves and DeLong tests assessed diagnostic performance.Results:The MSI-H group exhibited significantly higher CT values at 40-60 keV,Zeff,and K40-70 in plain scan compared to the MSS/MSI-L group(all P<0.05).Conversely,lower CT values at 40-70 keV,K40-70,IC in arterial,venous and delayed phases,and NIC in venous and delayed phases were observed in the MSI-H group(all P<0.05).The AUC values of the individual parameters for predicting MSI-H status ranged from 0.612 to 0.723.Logistic regression analysis identified CT value at 40 keV in plain scan and CT value at 50 keV in venous phase as independent predictors(both P<0.05),and their combination yielded superior diagnostic accuracy(AUC=0.746)compared to individual parameters.Conclusions:Quantitative spectral parameters from single-source DECT enable preoperative discrimination of MSI-H status in gastric cancer.The synergistic combination of CT value at 40 keV in plain scan and CT value at 50 keV in venous phase demonstrates enhanced diagnostic efficacy.关键词
胃肿瘤/微卫星不稳定/体层摄影术,X线计算机/能谱成像Key words
Stomach neoplasms/Microsatellite instability/Tomography,X-ray computed/Spectral imaging
