双层探测器光谱CT有效原子序数及碘浓度定量评估胃癌分化程度

Quantitative Evaluation of the Differentiation Degree of Gastric Cancer via Effective Atomic Number and Iodine Density of Dual Layer Detector Spectral CT

目的探讨双层探测器光谱CT有效原子序数及碘浓度定量评估胃癌分化程度的价值。资料与方法回顾性收集2020年10月-2021年10月昆明医科大学第一附属医院接受双层探测器光谱CT腹部平扫及三期动态增强扫描,并经手术病理证实的43例胃癌,根据病理结果分为中高分化组16例与低分化组27例。测量胃癌病灶及同层面腹主动脉动脉期、静脉期及延迟期有效原子序数和碘浓度,计算标准化有效原子序数及标准化碘浓度。比较增强各期两组各项参数的差异,对有统计学意义的参数绘制受试者工作特征曲线,评估诊断效能及计算相应阈值。结果低分化胃癌病灶增强三期有效原子序数(8.04±0.32比7.73±0.19、8.38±0.25比8.03±0.14、8.32±0.24比8.07±0.12)、标准化有效原子序数(0.71±0.04比0.67±0.03、0.88±0.02比0.84±0.03、0.91±0.03比0.88±0.02)、碘浓度[(1.40±0.56)mg/ml比(0.76±0.32)mg/ml、(1.99±0.54)mg/ml比(1.24±0.28)mg/ml、(1.89±0.48)mg/ml比(1.42±0.37)mg/ml]及标准化碘浓度(0.13±0.06比0.06±0.03、0.40±0.09比0.26±0.08、0.52±0.14比0.37±0.13)均高于中高分化组,差异均有统计学意义(t/t′=3.513~6.058,P均<0.05)。静脉期各项参数诊断胃癌分化程度的曲线下面积较大,静脉期有效原子序数、标准化有效原子序数、碘浓度、标准化碘浓度诊断胃癌分化程度的曲线下面积分别为0.903、0.853、0.900、0.885。结论双层探测器光谱CT有效原子序数、碘浓度可为术前评估胃癌分化程度提供更多信息,具有一定的临床应用价值。

Purpose To evaluate the differentiation degree of gastric cancer quantitatively by using the effective atomic number and iodine density of dual-detector spectral CT.Materials and Methods Data of 43 patients with gastric cancer confirmed by surgery and pathology from October 2020 to October 2021 in the First Affiliated Hospital of Kunming Medical University were retrospectively collected.All patients received abdominal plain CT with double detector and three phase dynamic enhanced scan.According to the degree of pathological differentiation,they were divided into high differentiation group(16 cases)and low differentiation group(27 cases).The effective atomic number and iodine density of gastric cancer lesions in arterial,venous and delayed stages and abdominal aorta at the same level were measured,and calculated the standardized effective atomic number and standardized iodine density.The differences of parameters between the two groups in enhanced scan was compared.Receiver operating characteristic curves were drawn for statistically significant parameters to evaluate diagnostic efficacy and calculate corresponding thresholds.Results The dynamic enhanced effective atomic number(8.04±0.32 vs.7.73±0.19,8.38±0.25 vs.8.03±0.14,8.32±0.24 vs.8.07±0.12),standardized effective atomic number(0.71±0.04 vs.0.67±0.03,0.88±0.02 vs.0.84±0.03,0.91±0.03 vs.0.88±0.02),iodine density[(1.40±0.56)mg/ml vs.(0.76±0.32)mg/ml,(1.99±0.54)mg/ml vs.(1.24±0.28)mg/ml,(1.89±0.48)mg/ml vs.(1.42±0.37)mg/ml]and standardized iodine density(0.13±0.06 vs.0.06±0.03,0.40±0.09 vs.0.26±0.08,0.52±0.14 vs.0.37±0.13)in the third stage of poorly differentiated gastric cancer lesions were higher than those in the highly differentiated group,with statistically significant differences(t/t′=3.513-6.058,all P<0.05),among which the area under curve of various parameters in the venous phase for diagnosis of gastric cancer differentiation was larger.The area under curve of effective atomic number in venous phase,standardized effective atomic number in venous phase,iodine density in venous phase and standardized iodine concentration in venous phase for diagnosis of gastric cancer differentiation were 0.903,0.853,0.900 and 0.885 respectively.Conclusion The effective atomic number and iodine density of dual-detector spectral CT can provide more information for preoperative diagnosis of gastric cancer differentiation,and have certain clinical application value.