双能量CT碘值及增强值与进展期胃腺癌病理分化程度的相关性

Correlations Between the Iodine Value and CT Enhancement Value of Dual-Energy CT and the Pathological Differentiation Degree of Advanced Gastric Adenocarcinoma

目的探讨双能量CT碘值及CT增强值与进展期胃腺癌病理分化程度的相关性,并比较两者的诊断效能。方法回顾性分析经手术病理证实且术前均做双能量CT双期增强的进展期胃腺癌45例临床及影像资料,18例为中/高分化腺癌,27例低分化腺癌。测量动、静脉期癌肿的CT增强值[100 kV、140 kV、0.5混合能量(相当于120 kV)]以及碘浓度值(IC)、标准化碘值(NIC),分析以上CT参数与胃腺癌病理分化程度的相关性,将有统计学差异的参数进一步做受试者工作特征曲线(ROC)分析。结果中/高分化腺癌与低分化腺癌的肿瘤组织在动脉期100 kV的CT值为(74.51±10.70)HU、(86.22±21.88)HU(P=0.036),动脉期IC分别为(1.48±0.27)mg/ml、(2.16±0.85)mg/ml(P<0.001),动脉期NIC分别为(14.84±4.14)%、(21.15±7.54)%(P=0.002);静脉期100 kV的CT值分别为(95.20±8.99)HU、(104.04±24.70)HU(P=0.007),静脉期0.5混合能量的CT值分别为(79.47±6.61)HU、(88.13±14.44)HU(P=0.006),静脉期IC分别为(2.07±0.49)mg/ml、(3.08±0.72)mg/ml(P<0.001),静脉期NIC分别为(44.53±6.42)%、(60.12±6.32)%(P<0.001),存在统计学差异。ROC分析结果显示,动脉期100 kV CT值AUC=0.686,静脉期100 kV CT值AUC=0.739,静脉期0.5混合能量AUC=0.746,静脉期IC AUC=0.891,静脉期NIC AUC=0.948。当静脉期NIC阈值设为48%时,鉴别胃腺癌病理分化程度的效能最高,敏感度为83.33%、特异度为97.84%。结论双能量CT的碘值定量分析可评估进展期胃腺癌的病理分化程度,其相关性高于不同管电压下CT增强值的评估,其中以静脉期NIC的诊断效能最高。

Objective To explore the correlations of the iodine value and enhancement value of the dual-energy CT with pathological differentiation degree of advanced gastric adenocarcinoma,and to compare their diagnostic efficacy.Methods Clinical and Imaging data of 45 patients with pathologically proved advanced gastric adenocarcinoma were retrospectively analyzed,including 18 patients with moderate/highly differentiated adenocarcinoma and 27 patients with poorly differentiated adenocarcinoma.All the subjects underwent the dual-energy CT dual-stage enhancement scan before the surgery.The CT enhancement values in arterial and venous phase(100 kV,140 kV,0.5 mixed-energy(relative to 120 kV)),iodine concentration value(IC)and normalized iodine value(NIC)of the carcinoma in each subject were measured,and their correlations with the degree of pathological differentiation were evaluated.For the values with statistical significance,receiver operating characteristic curve(ROC)analysis was further performed to explore their diagnostic efficiency.Results There were significant differences between the moderate/highly and the poorly differentiated adenocarcinoma in CT enhancement values of 100 kV arterial phase(74.51±10.70 HU vs 86.22±21.88 HU,P=0.036),IC of the arterial phase(1.48±0.27 mg/ml vs 2.16±0.85 mg/ml,P<0.001),NIC of the arterial phase((4.84±4.14)%vs(21.15±7.54)%,P=0.002),CT enhancement values of 100 kV venous phase(95.20±8.99 HU vs 104.04±24.70 HU,P=0.007),CT enhancement values of 0.5 mixed-energy venous phase(79.47±6.61 HU vs 88.13±14.44 HU,P=0.006),IC of the venous phase(2.07±0.49 mg/ml vs 3.08±0.72 mg/ml,P<0.001),and NIC of the venous phase((44.53±6.42)%vs(60.12±6.32)%,P<0.001).ROC curve analysis shows 100 kV arterial phase(AUC=0.686),100 kV venous phase(AUC=0.739),0.5 mixed-energy venous phase(AUC=0.746),IC venous phase(AUC=0.891),and NIC venous phase(AUC=0.948).And it was most effective to distinguish the pathological differentiation degree of gastric adenocarcinoma when the threshold of the NIC venous phase was set to 48%,with a sensitivity of 83.33%and a specificity of 97.84%.Conclusion The quantitative analysis of IC of dual-energy CT can predict the pathological differentiation degree of advanced gastric adenocarcinoma,with a higher correlation than the CT enhancement values under different tube voltages.And the diagnostic efficiency of NIC of the venous phase is the best.