分段读出扩散加权成像序列表观扩散系数在前列腺癌鉴别诊断中的价值

Readout segmentation of long variable echo-trains： a preliminary study regarding the diagnosis of prostate cancer

目的 探讨分段读出扩散加权成像（RESOLVE）序列ADC值鉴别前列腺癌和良性前列腺增生的价值.方法 回顾性分析经超声引导下直肠穿刺活检病理证实、行前列腺MRI检查（T1WI、T2WI及RESOLVE序列）,且MRI检查前未进行过穿刺活检、内分泌治疗或放射治疗的72例患者纳入研究.将患者分为2组：前列腺癌组23例（43个病灶）和前列腺增生组49例（64个病灶）.患者均行前列腺MR检查.由2名医师先采用双盲法独立对图像进行评估,并采用组内相关系数（ICC）值和Bland-Altman图,分析2名观察者测量ADC值的一致性.计算2名医师测量RESOLVE序列ADC值的平均值,并采用独立样本t检验比较前列腺癌组和前列腺增生组ADC值的差异.以病理结果为金标准,绘制ADC值诊断前列腺癌的ROC曲线,判断最佳诊断界值点,计算ADC值诊断前列腺癌的敏感度、特异度和准确度.结果 2名观察者测量ADC值的一致性好（ICC=0.976,P＜0.01）.前列腺癌组的ADC值为（0.74±0.12）×10-3s/mm2（95％可信区间为0.70×10-3～0.78×10-3s/mm2）,前列腺增生组的ADC值为（1.21±0.12）×10-3s/mm2（95％可信区间为1.18×10-3～1.24×10-3s/mm2）,差异有统计学意义（t=19.223,P＜0.01）.ADC值诊断前列腺癌的ROC曲线下面积为0.996,最佳诊断界值为0.946×10-3s/mm2,诊断前列腺癌的敏感度为95.3％（41/43）,特异度为98.4％（63/64）,准确度为97.2％（104/107）.结论 RESOLVE序列ADC值鉴别前列腺癌和良性前列腺增生具有一定价值.

Objective To explore the value of readout segmentation of long variable echo-trains （RESOLVE） in the differentiation of prostate cancer from benign prostatic hyperplasia （BPH）.Methods Seventy two consecutive patients with suspected prostate cancer were evaluated by 3.0 T MR examination （RESOLVE sequence included,b values=0 and 800 s/mm2） were included in our retrospective study.All the patients had ultrasound guided systemic biopsy with histopathological diagnosis.The patients were divided into group A （23 prostate cancer cases with total 43 malignant lesions） and group B （49 BPH cases with total 64 benign lesions）.Two radiologists who were blinded to the clinical data quantitatively analyzed the ADC values of suspicious lesions independently.Inter-reader agreement for ADC values was assessed with Bland and Altman test,and the intra-class correlation coefficient （ICC）.Difference of ADC values in two groups was assessed by student＇s t test.Receiver operating characteristic curve （ROC） was used to determine the best predictor and cutoff value.Results A total of 107 lesions （43 malignant and 64 benign） were identified in 72 patients.ICC was 0.976,P〈0.01.The mean ADC value of prostate cancer is lower than BPH （t=19.223,P〈0.01）,（0.74±0.12） ×10 3 and （1.21±0.12） × 10-3mm2/s respectively.Diagnostic cut-off point was 0.946× 10-3mm2/s,diagnostic sensitivity 95.3 % （41/43）,specificity 98.4% （63/64）,accuracy 97.2% （104/107）.Conclusion RESOLVE ADC value is valuable in the differential diagnosis of prostate cancer and BPH.