多高b值扩散加权成像联合T2WI对移行区前列腺癌的诊断价值

The combined value of multi-high b-value diffusion-weighted imaging and T2WI in the diagnosis of transitional zone prostate cancer

目的探讨多高b值扩散加权成像联合T2WI对移行区前列腺癌的诊断价值。方法回顾性分析2018年1月至2019年10月北部战区总医院放射诊断科行前列腺常规磁共振成像(MRI)、弥散加权成像(DWI)[常规b值DWI(SB-DWI,b=1000 s/mm^2)及多高b值DWI(MB-DWI,b值分别为2000 s/mm^2、3000 s/mm^2)]检查并行穿刺活检或手术病理证实移行区病变的70例患者临床资料。其中移行区前列腺癌(TZ-PCa)30例,移行区前列腺增生(TZ-BPH)40例。采用独立样本t检验分析TZ-PCa组与TZ-BPH组表观扩散系数(ADC)的差异;采用受试者操作特征(ROC)曲线分析3种b值下ADC值对TZ-PCa的诊断效能。检查方法分为3种:A[T2WI+SB-DWI(b=1000 s/mm^2)]、B[T2WI+SB-DWI(b=1000 s/mm^2)+MB-DWI(b=2000 s/mm^2)]、C[T2WI+SB-DWI(b=1000 s/mm^2)+MB-DWI(b=3000 s/mm^2)],采用χ2检验比较3种方法对TZ-PCa、TZ-BPH的诊断效能。并以前列腺术后病理为依据,分析3种方法对TZ-PCa诊断的敏感性及特异性。结果3种b值(1000、2000、3000 s/mm^2)下TZ-PCa组ADC分别为0.928±12.21、0.794±8.41、0.594±9.29;TZ-BPH组ADC分别为1.026±12.34、0.848±10.79、0.679±14.67。TZ-PCa组ADC明显低于TZ-BPH组(t分别为-5.142、-4.066、-3.291,均P<0.01)。3种检查方法以C方法对TZ-PCa诊断的敏感性、特异性及准确性最高(χ^2=10.825,P<0.01)。b=3000 s/mm^2时对TZ-PCa的诊断效能最高,ADC最佳临界点为0.722。结论MB-DWI(b=3000 s/mm^2)与T2WI+SBDWI(b=1000 s/mm^2)联合使用对TZ-PCa的诊断效能最高,有良好的应用前景。

Objective To evaluate the value of multi-high b-value diffusion-weighted imaging(DWI)combined with T2WI in the diagnosis of transitional zone prostate cancer.Methods Seventy patients with transitional zone lesions confirmed by routine magnetic resonance imaging(MRI),DWI[single-b-value DWI(SB-DWI,b=1000 s/mm^2)and multi-high b-value DWI(MB-DWI,b=2000 s/mm^2,3000 s/mm^2)]examinations,puncture biopsy,or surgical pathology in the Department of Radiology at the General Hospital of Northern Theater Command from January 2018 to October 2019 were analyzed retrospectively,including 30 cases of transitional zone prostate cancer(TZ-PCa)and 40 cases of benign prostatic hyperplasia(TZ-BPH).The difference in the apparent diffusion coefficient(ADC)values between the TZ-PCa group and the TZ-BPH group was analyzed by independent sample t test.The diagnostic efficiency of the ADC values for the three b values for TZ-PCa was analyzed by receiver operating characteristic(ROC)curve.Detection methods included:A,T2WI+SB-DWI(b=1000 s/mm^2);B,T2WI+SB-DWI(b=1000 s/mm^2)+MB-DWI(b=2000 s/mm^2);and C,T2WI+SB-DWI(b=1000 s/mm^2)+MB-DWI(b=3000 s/mm^2).The efficiencies of the three methods in the diagnosis of TZ-PCa and TZ-BPH were compared by the χ^2 test.The sensitivities and specificities of the three methods for the diagnosis of TZ-PCa were analyzed based on pathology after prostate surgery.Results Based on the three b values(1000,2000,3000 s/mm^2),the ADC values of the TZ-PCa group were 0.928±12.21,0.794±8.41,and 0.594±9.29,respectively.The ADC values of the TZ-BPH group were 1.026±12.34,0.848±10.79 and 0.679±14.67,respectively.The ADC values of the TZ-PCa group were significantly lower than that of the TZ-BPH group(t=-5.142,-4.066,-3.291,respectively,all P<0.01).The sensitivity,specificity,and accuracy of method C for the diagnosis of TZ-PCa were the highest(χ^2=10.825,P<0.01).When b=3000 s/mm^2,the diagnostic efficiency of TZ-PCa was the highest,and the optimal critical point of ADC was 0.722.Conclusion The combined use of MB-DWI(b=3000 s/mm^2)and T2WI+SB-DWI(b=1000 s/mm^2)has the highest diagnostic efficiency for TZ-PCa and has good application prospects.