不同最小b值的ADC值在肾透明细胞癌术前分级中的对比研究

目的探讨不同最小b值下的表观弥散系数（apparentdiffusioncoefficient，ADC）对肾透明细胞癌（clearcellrenalcellcarcinoma，CCRCC）术前分级的影响。方法回顾性分析32例CCRCC患者的影像学资料及病理资料。根据Fuhrman核分级法分为低级别组（FuhrmanI和Ⅱ级）和高级别组（FuhrmanⅢ和Ⅳ级）。参考常规序列，由一位放射科医师在肿瘤实质区手动勾画大小约0．35～O．45cm^2的感兴趣区，记录各b值（O，200，400，600，800和1000s／mm^2）对应的信号强度值。采用最小b值分别为0和200s／mm^2计算得到ADCO～1000和ADC200～1000。采用配对t检验比较两组b值的ADC的差异；采用两独立样本t检验分析高低级别CCRCC的ADC值的差异；ADC值与病理分级的相关性研究采用Spearman秩相关分析。结果20例为低级别组，12例为高级别组。32例CCRCC的ADC0～1000为（1．840±0．308）×10^-2mm^2／S，ADC200～1000为（1．429±0．317）×10。mm。s，两组间有统计学差异（t＝12．78，P＝0．00）。其中，低级别CCRCC的ADCO～1000值为（1．893±0．315）×10^-3mm^2／s，高级别的ADC0～1000值为（1．752±0．286）×10。mm。／s，组间无统计学差异（t＝1．272，P＝0．213）；低级别CCRCC的ADC200～1000值为（1．519±0．335）×10^-3mm^2／s，高级别的ADC200～1000值为（1．279±0．224）×10。mm。／s，组间有统计学差异（t＝2．196，P=0．036）。ADC200-1000与CCRCC病理分级呈反相关（r＝0．344，P＝0．047）。结论与ADC0～1000相比，ADC200～1000改善了ADC值在肾透明细胞癌术前分级中的价值。

The effect of ADC from different minimal b-value on grading of CCRCC preoperatively

Abstract] Objective To probe the effect of apparent diffusion coefficient （ADC） from different minimal b-value on the grading of clear cell renal cell carcinoma （CCRCC） preoperatively. Methods The imaging and pathological data of 32 cases with CCRCC was assessed retrospectively. There were low grade （Fuhrman I and Ⅱ） and high grade （Fuhrman Ⅲ and Ⅳ） confirmed by pathological test. Based on the conventional MR images, the region of interesting, ranging from 0.35 cm^2 to 0.45 cm^2 in neoplastic parenchyma, was plotted by a radiologist. The values of signal intensity on DWI at b=0, 200, 400, 600, 800 and 1000 s/mm^2 were recorded. The ADC0-1000 was calculated from images at b during 0 to 1000 s/ mm~ and ADC200- 1000 from that at b during 200 to 1000 s/ram2. The ADC0～1000 and ADC200~1000 were compared by paired t test; the differences were examined by two sample t test between high and low grades; and the correlation be- tween ADC and Fuhrman grading was tested by Spearman. Results 32 case with 32 tumors were analyzed in this study, including 20 cases of high grade and 12 cases of low grade. The ADC0～1000 was （1. 840±0. 308） ）〈 10^-3 mm^2/s and ADC200～1000 was （1. 429±0. 317） × 10 3 mm^2/s, a significant difference was found （ t = 12.78, P = 0.00）. The ADC0～1000 was （1. 893±0. 315） ）〈 10^-3 mm^2/s in low grade and （1. 752±0. 286） X 10^-3 mm^2/s in high grade, the difference can＇t be shown （ t =1. 272, P =0. 213）. The ADC200～1000 was （1. 519±0. 335） × 10 3 mm^2/s in low grade and （1. 279 ± 0.224） × 10 3 mm^2/s in high grade, the difference was found （ t = 2.196, P = 0.036）, and the negative correlation exis- ted between ADC200～1000 and grading of CCRCC （ r =-0. 344, P =0. 047）. Conclusion Compared to ADC0～1000, ADC200～1000 improved the evaluation of the grading of CCRCC preoperatively based on ADC.