前列腺局限性病变良恶性鉴别诊断:弥散加权成像图与表观弥散系数值比较

Differential diagnosis of localized prostate cancer:comparing diffusion weighted imaging with apparent diffusion coefficients

背景与目的:局限性前列腺癌检出日益增多,未突破包膜的癌灶与炎性反应增生等良性病变的鉴别对早期诊断及治疗具有重要意义。本研究旨在比较3.0T磁共振弥散加权成像(diffusion weighted imaging,DWI)和表观弥散系数(apparent diffusion coefficient,ADC)在前列腺局限性病变良恶性鉴别诊断中的价值。方法:经穿刺或手术病理证实的局限性前列腺癌患者69例,其中外周带(peripheral zone,PZ)和中央腺体(central gland,CG)病变分别43和26例,慢性炎性反应33例和良性增生37例,测量并比较病灶的ADC值(b=0,1 000 s/mm2)、DWI图像上信噪比(signal noise ratio,SNR)和半定量分级,应用受试者工作曲线评价诊断效能。结果:PZ中45处癌灶、36处炎性反应;CG中27处癌灶、42处增生。ADC值鉴别PZ、CG良恶性病变的灵敏度和特异度分别为88.9%和86.1%、81.5%和73.8%,其诊断效能高于半定量DWI分级和SNR(P<0.05)。结论:ADC值诊断前列腺局限性病变的效能优于DWI图像,可作为一项良好的鉴别诊断指标。

Background and purpose： Since the detection of localized prostate cancer is increasing, it＇s important to distinguish from benign lesions like prostatitis. This study aimed to compare diffusion weighted imaging with apparent diffusion coefficients in differential diagnosis of localized prostate cancer on 3.0T MR. Methods： Sixty- nine cases with localized prostate cancer proved by pathology, 43 in perpheral zone （PZ） and 26 in central gland （CG）, 33 with prostatitis, and 37 with benign prostatic hyperplasia （BPH） were analyzed. The signal noise ratio （SNR） and apparent diffusion coefficient （ADC） value of lesions were measured, and a semiquantitative grading of DW image was performed. The diagnostic accuracy of both methods was evaluated by ROC. Results： 45 cancer foci and 36 prostatitis lesions in PZ, 27 cancer loci and 42 BPH lesions in CG were included. The sensitivity and specificity for ADC value to distinguish cancer from begin lesions in PZ and CG were 88.9% and 86.1%, 81.5% and 73.8% respectively. The diagnostic accuracy of ADC value was higher than DWI semiquantitative grading and SNR （P〈0.05）. Conclusion： ADC value yielded a higher accuracy in differential diagnosis of localized prostate cancer on 3.0T MR, thus it＇s recommended as a maior index for diagnosis.