双能CT多参数测量对胃癌Lauren分型的诊断价值

Diagnostic value of dual-energy CT with multimodal parameters in Lauren classification of gastric carcinoma

目的:探索双能CT(DECT)多模态参数术前预测胃癌Lauren分型的价值。方法:搜集有完整双能CT扫描资料并经手术病理证实的67例胃癌患者的病例资料,其中Lauren分型为弥漫型、肠型和混合型者分别为33、19和15例。通过双能CT后处理软件得到碘图,测量动、静脉期图像上病灶的CT值及其差值(△CT)、碘浓度、碘图CT值(Overlay值)。采用多重比较单因素方差分析对不同分型间各参数值的差异进行统计学分析,对有统计学意义的参数进一步绘制其受试者工作特征曲线(ROC),评价各参数的诊断效能,按约登指数最大为原则得出诊断阈值及曲线下面积(AUC)。结果:弥漫型胃癌的动、静脉期碘浓度和Overlay值及△CT值分别为(1.61±0.68)、(2.77±0.72)mg/mL及(38.94±18.66)、(66.17±18.23)和(41.21±13.17)HU;肠型胃癌的上述参数值分别为(1.06±0.58)、(1.53±0.44)mg/mL及(26.16±12.70)、(38.91±10.67)和(22.74±10.73)HU;混合型胃癌的上述参数值分别为(1.08±0.41)、(1.77±0.45)mg/mL及(26.38±10.31)、(43.37±8.03)和(28.40±9.58)HU。弥漫型胃癌的各项参数值均明显高于肠型及混合型胃癌,差异均有统计学意义(P<0.05);而肠型与混合型两组间各项参数值的差异均无统计学意义(P>0.05)。动脉期碘浓度和Overlay值、静脉期碘浓度和Overlay值及△CT值诊断弥漫型胃癌的AUC分别为0.736、0.709、0.944、0.927和0.858,诊断阈值分别为1.05 mg/mL、28.75 HU、1.95 mg/mL、36.70 HU和30.50 HU,其中以静脉期碘浓度及Overlay值的诊断效能最佳。结论:双能CT多参数测量有助于术前预测胃癌的Lauren分型,其中以静脉期碘浓度和Overlay值的诊断效能最佳。

Objective:To explore the value of multimodal parameters of dual-energy CT(DECT)in preoperative prediction of Lauren classification of gastric cancer.Methods:A total of 67 patients with gastric cancer confirmed by operation and pathology were collected.Among them,there were 33,19 and 15 cases with diffuse,intestinal and mixed Lauren type,respectively.The iodine concentration,overlay value,CT values of the lesions were measured in arterial and venous phases on DECT images.The difference of CT values between arterial and venous phases was calculated and compared with postoperative pathology results.ANOVA was used for statistical analysis.Parameters with statistical significance were used to create the receiver operating characteristic curve(ROC)so as to evaluate the diagnostic efficacy of each index,respectively.The diagnostic threshold and the area under the curve(AUC)were obtained according to the principle of maximum Youden index.Results:The iodine concentration and overlay value in arterial and venous phases and the difference of CT values between arterial and venous phases(△CT)of diffuse type gastric carcinoma were(1.61±0.68)mg/mL,(38.94±18.66)HU,(2.77±0.72)mg/mL,(66.17±18.23)HU and(41.21±13.17)HU;those five parameters of intestinal type were(1.06±0.58)mg/mL,(26.16±12.70)HU,(1.53±0.44)mg/mL,(38.91±10.67)HU and(22.74±10.73)HU;and those of mixed type were(1.08±0.41)mg/mL,(26.38±10.31)HU,(1.77±0.45)mg/mL,(43.37±8.03)HU and(28.40±9.58)HU.The values of five parametres in diffuse type group were higher than those in mixed type group and intestinal type group with statistical differences(P<0.05);but there were no statistical differences in the five parametres between the mixed type group and intestinal type group(P>0.05).The AUC of iodine concentration and overlay value in arterial phase,iodine concentration and overlay value in venous phase,and△CT for diagnosis of diffuse gastric carcinoma was 0.736,0.709,0.944,0.927 and 0.858,respectively;and the diagnostic threshold was 1.05mg/mL,28.75HU,1.95mg/mL,36.7HU and 30.5HU,respectively.Among them,iodine concentration and overlay value in venous phase demonstrated the best diagnostic efficiency.Conclusion:Dual-energy CT examimation with multi-parameter measurements is helpful for preoperative prediction of Lauren classification of gastric cancer.Iodine concentration and overlay value in venous phase demonstrate the best diagnostic efficacy.