磁共振灌注加权成像定量参数在前列腺外周带前列腺癌鉴别诊断中的价值

Quantitative assessment of vascular kinetics using perfusionweighted MRI for the differentiation of prostate cancer in the peripheral zone

目的探讨磁共振灌注成像(perfusion weighted MRI,PWI)定量参数在前列腺外周带前列腺癌鉴别诊断中的价值。材料与方法回顾性分析51例行3.0 T MR PWI扫描,T2WI表现为局灶性低信号病变,并经6针或12针系统穿刺活检病理证实的患者资料,其中前列腺癌25例,良性病变26例。前列腺癌组有6例患者采用前列腺根治切除进一步证实。两名医师在不知道病理结果和临床资料的前提下参照T2WI外周带低信号区,协商取得一致后共同在PWI病灶区放置ROI,测量病灶区PWI定量参数转运常数(Ktrans)、血管外细胞外间隙体积百分数(Ve)及速率常数(Kep)。根据病理结果,将病灶分为前列腺癌灶组和良性前列腺病灶组。采用独立样本t检验比较Ktrans、Kep、Ve在前列腺癌和良性病灶中的差异。采用ROC曲线分析PWI定量参数鉴别前列腺癌和良性改变中的价值。结果前列腺癌和良性前列腺病灶组的Ktrans、Kep、Ve分别为(0.150±0.046)V S(0.0 8 6±0.0 3 7)、(0.5 1 8±0.1 8 1)V S(0.3 2 5±0.1 4 2)、(0.2 8 8±0.1 4 7)VS(0.306±0.141),两组间Ktrans和Kep独立样本t检验结果差异有统计学意义(P<0.01),Ve之间差异无统计学意义(P=0.61)。Ktrans、Kep、Ve诊断前列腺癌和前列腺良性病变的曲线下面积分别为0.885、0.803、0.554。分别以0.108 min-1、0.38 min-1为界值点,Ktrans、Kep鉴别前列腺癌和良性前列腺病灶的敏感性及特异性分别为86.11%、80.6%和79.32%、75.9%。结论 PWI定量参数Ktrans、Kep在前列腺外周带前列腺癌鉴别诊断中具有重要价值。

Objective： To assess vascular kinetics using perfusion-weighted MRI （PWI） in the differentiation of prostate cancer in the peripheral zone. Materials and Methods： Fifty-one patients with low T2 signal nodules in the prostate peripheral zone underwent PWI-MRI at 3 T were included in these study. K^trans, Kep and Vc were compared between prostate cancer and benign nodules. Receiver operating characteristic（ROC） curve analyses were performed to determine the diagnostic accuracy of K^trans Kep and Vc. Results： The average values of K^trans Kep and Vc for prostate cancer and begin lesions were （0.150±0.046） vs （0.086±0.037）, （0.518±0.181 ） vs （0.325±0.142） and （0.288±0.147） vs （0.306±0.141）, respectively. There was statistically significant difference in K^trans, Kep between prostate cancer and begin noduless （P〈0.01）. However, there was no statistically significant difference in Vc. The sensitivity, specificity for determining the prostate cancer of K^trans, Kep were 86.11%,80.6% and 79.32%, 75.9%, respectively. Conclusions： Quantitative assessment of vascular kinetics using PWI is useful in the differentiation of prostate cancer in the peripheral zone.