640层容积CT双低剂量肾透明细胞癌动态灌注成像的应用

Application of Double Low Dose and Dynamic Perfusion Imaging in the Diagnosis of Renal Clear Cell Carcinoma with 640-Slice Volume CT

目的通过640层容积CT行肾透明细胞癌双低剂量(低辐射剂量、低对比剂用量)灌注成像,探讨灌注参数评估肾透明细胞癌病理分级的价值。方法回顾性分析经病理证实的53例肾透明细胞癌患者的640层容积CT双低剂量灌注图像。扫描数据经后处理所得24个数据包,采用patlak和最大斜率软件,获得等效血容量(Equivalent Blood Volume, Equiv BV)和表面渗透性(Permeability Surface,PS)和血流量(Blood Flow,BF)。采用对比剂48 mL,生理盐水30 mL,注射速度为6 m/s。根据病理分级,53例患者分为Ⅰ级8例,Ⅱ级22例,Ⅲ级15例,Ⅳ级8例。比较不同病理分级肿瘤灌注值(Equiv BV、BF、PS)的差异,运用ROC曲线评估各指标的诊断效能。结果肿瘤EquivBV、PS、BF值与病理分级呈显著负相关(P<0.05)。除Ⅰ级与Ⅱ级PS值、Ⅲ级与Ⅳ级Equiv BV值和BF值之间差异无统计学意义外,其余不同分级灌注值之间差异均存在统计学意义(P均<0.05)。Ps值对病理级别的诊断效能最高,AUC0.829,临界值37.35 (mL·100g^(-1)·min^(-1)),敏感性80.0%,特异性78.0%。结论 640层容积CT双低剂量灌注成像可作为肾透明细胞癌术前分级预测的新的定量检查手段,有较高的临床应用价值。

Objective To evaluate the value of perfusion parameters in pathological grading of Renal clear cell carcinoma with640-slice volume computer tomography double low dose perfusion imaging. Methods The 640-slice volume computer tomography double low dose perfusion imaging was retrospectively analyzed in 53 patients with pathologically proven Renal clear cell carcinoma(RCC). Scan data included 24 packets and all packets were analyzed with Patlak and the maximum slope software, the equivalent blood volume(Equiv BV) and permeability surface(PS) and blood flow(BF) were obtained. A bolus of 48 mL contrast agent( Iopamidol, 370 mgI/mL), followed by 30 mL saline at a flow rate of 6 mL/sec. According to pathological grading(Fuhrman classification), 53 patients were divided into Ⅰgrade 8 cases,Ⅱ grade 22 cases,Ⅲ grade 15 cases,Ⅳ grade8 cases. The differences of tumor perfusion values(Equiv BV, BF, PS) in different pathological grades were compared, and the ROC curve to evaluate the diagnostic efficiency was used. Results There was a significant negative correlation between tumor Equiv BV, PS, BF and pathological grading(P<0.05). Except the Ps value in grade I and Ⅱ, the Equiv BV and BF values in grade Ⅲ and IV, there were significant differences between any two grades(P<0.05). The diagnostic value of Ps was the highest for pathological grade, AUC was 0.829, the critical value was 37.35(mL·100 g-1·min-1), sensitivity was 80.0%, specificity was 78.0%. Conclusion The640-slice volume computer tomography double low dose perfusion imaging can be used as a new quantitative method for predicting the preoperative classification of Renal clear cell carcinoma, and has a high clinical value.