单、双指数模型DWI诊断中央叶前列腺癌及前列腺增生的价值

Diagnosis value of monoexponential and biexponential diffusion-weighted imaging for central gland prostate cancer and prostatic hyperplasia

目的 比较扩散加权成像（DWI）单指数模型ADCtotal及双指数模型ADCslow、ADCfast、f值在中央叶前列腺癌、腺体型前列腺增生、基质型前列腺增生诊断及鉴别诊断中的应用价值。方法 回顾性分析经磁共振超声融合靶向穿刺证实的中央叶前列腺癌患者23例、腺体型前列腺增生患者19例、基质型前列腺增生患者24例的临床资料。所有病例均于穿刺前行包括T2WI、T1WI及多b值DWI在内的MRI检查。DWI的b值设置为0、50、100、150、200、500、800、1 000、1 500和2 000s/mm2。根据病理结果将靶向穿刺区病灶同DWI图像进行匹配。分别测定各病理类型的ADCtotal、ADCslow、ADCfast、f值。采用Kruskal-Wallis检验进行差异性比较,受试者工作特征（ROC）曲线分析各参数诊断及鉴别诊断中央叶前列腺癌、腺体型前列腺增生、基质型前列腺增生的诊断效能。结果 中央叶前列腺癌、腺体型前列腺增生、基质型前列腺增生的ADCtotal值分别为（0.46±0.06）、（0.87±0.19）、（0.68±0.09）×10-3 mm2/s,ADCslow分别（0.39±0.13）、（0.57±0.15）、（0.49±0.13）×10-3 mm2/s,ADCfast分别为（4.8±2.5）、（3.6±0.76）、（4.5±1.8）×10-3 mm2/s,f值分别为0.43±0.10、0.68±0.09、0.58±0.08。ADCtotal、ADCslow、f值在各组之间差异有统计学意义（P=0.000、0.001和0.000）,ADCfast在各组间差异无统计学意义（P=0.489）。ADCtotal、ADCslow、f值在鉴别中央叶前列腺癌和腺体型前列腺增生时曲线下面积（AUC）分别为1、0.828、0.971,在鉴别中央叶前列腺癌和间质性前列腺增生时AUC分别为0.991、0.719、0.861,在鉴别中央叶腺体型前列腺增生和间质性前列腺增生时AUC分别为0.876、0.650、0.831。结论 在b值位于0~2 000s/mm2时单指数模型的ADCtotal较双指数模型的ADCslow和f值在诊断及鉴别诊断中央叶前列腺癌、腺体型前列腺增生、基质型前列腺增生时具有更佳的诊断效能。

Objective To compare the diagnosis values of the standard apparent diffusion coefficient（ADCtotal）that calculated from the monoexponential diffusion-weighted imaging（DWI）and the parameters（slow apparent diffusion coefficient[ADCslow],fast apparent diffusion coefficient[ADCfast]and fraction of ADC [f]）derived from the biexponential DWI for central gland（CG）prostate cancer,glandular prostatic hyperplasia（GH）and stromal prostatic hyperplasia（SH）.Methods The clinical data of 23 patients with CG prostate cancer,19 patients with GH and 24 patients with SH,who were proven by magnetic resonance/transrectal ultrasound（MR/TRUS）fusion-guided target biopsy were retrospectively analyzed.All the patients underwent MRI examination including T2 WI,T1WI and b-value DWI before biopsy.The b-values of DWI were 0,50,100,150,200,500,800,1 000,1 500 and 2 000s/mm2.The match of target biopsy area and DWI images was done based on the pathology results.Then the ADCtotal,ADCslow,ADCfastand f values were measured for all the pathological types.KruskalWallis test was used for difference comparison,and receiver operating characteristic（ROC）analysis was performed to analyze each parameter and evaluate their diagnostic efficiency for CG prostate cancer,SH and GH.Results The ADCtotal（×10-3mm2/s）values of CG prostate cancer,GH and SH were（0.46±0.06）,（0.87±0.19）and（0.68±0.09）;the ADCslow（×10-3mm2/s）values were（0.39±0.13）,（0.57±0.15）and（0.49±0.13）;the ADCfast（×10-3 mm2/s）values were（4.8±2.5）,（3.6±0.76）and（4.5±1.8）;and the f values were（0.43±0.10）,（0.68±0.09）and（0.58±0.08）,respectively.There were significant differences in ADCtotal,ADCslowand f values among different groups（P=0.000,0.001 and 0.000）,but not in ADCfastvalues（P=0.489）.The area under curve（AUC）of ADCtotal,ADCslowand f value for CG prostate cancer and GH were1,0.828,and 0.971,respectively.The AUC values of ADCtotal,ADCslowand f value for differential diagnosis of CG prostate cancer and SH were 0.991,0.719,and 0.861,respectively.The AUC values of ADCtotal,ADCslowand f value for GH and SH were 0.876,0.650,and 0.831,respectively.Conclusion When b value is 0-2 000s/mm2,the ADCtotalthat calculated from the monoexponential model for diagnosis of CG prostate cancer,GH and SH is more efficient than the ADCslow and f value that derived from biexponential model.