摘要目的 以前列腺癌根治术后整体组织病理切片（前列腺大切片）检测评估MRI弥散加权成像(DWI)在前列腺癌定位诊断中的价值。 方法 回顾性分析2009年10月至2010年6月腹腔镜下前列腺癌根治术19例患者的临床资料，术前行MRI、DWI检查。术后前列腺标本制成前列腺大切片。应用“六分区法”进行分区，由2位阅片者“盲法”阅读MRI和MRI/DWI片，对每个分区分5档诊断：①正常；②可能正常；③不确定；④可能是癌；⑤肯定是癌。2位阅片者所得结果的平均值≥4认定该区域为前列腺癌区域，与术后前列腺大切片比对。 结果 19例前列腺癌患者共114个分区，前列腺大切片证实前列腺癌区域48个(42％)，其中基底部、中部、尖部分别为15个(39％)、21个(55％)和12个(32％)，前列腺癌呈明显的多灶性分布。MRI前列腺癌定位诊断的敏感性、特异性分别为62.5％和69.7％，加用DWI后敏感性、特异性提高至79.2％和80.3％。前列腺尖部和中部肿瘤MRI诊断的敏感性为46.7％和66.7％，加用DWI后敏感性分别提高至73.3％和85.8％。 结论 加用DWI可以明显提高MRI对前列腺癌定位诊断的敏感性，特别是对于前列腺尖部和中部的肿瘤。

abstractsObjective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology.Methods We treated 36 patients using laparoscopic radical prostatectomy from Oct. 2009 to Jun. 2010. Patients who did not have an MRI/DWI examination or a surgical history of prostate and previous hormonal therapy were excluded, leaving 19 patients in our study. We analyzed the MRI and DWI collected before radical prostetectomy surgey and the post-surgery step section pathology made by the whole mount technique. The prostatic gland was divided into six sections. Two doctors read the MRI/DWI without knowing the patients' information and scored, using a 5 point scale, for each section. The tissue was graded according to the following scale: 1-definitely no cancer, 2-probably no cancer, 3-possible cancer, 4-probable cancer and 5-definite cancer. When the average score ≥4 the region was assumed to be the prostate cancer region by MRI or MRI/DWI. Results In 19 patients with 114 regions, there were 48 (42％) prostate cancer regions approved by whole-mount step section pathologically.The number of prostate cancer regions was 15 (39％), 21 (55％) and 12 (32％) in base, mid and apex parts respectively. The sensitivity and specificity of the MRI was 62.5％ and 69.7％. When considering DWI, the specificity and sensitivity was elevated to 79.1％ and 83.3％. As for the apex and mid parts, the sensitivities of MRI were a little bit low (46.7％ and 66.7％ ). But the sensitivities of localization of prostate cancer for the apex and mid of prostate were elevate to 73.3％ and 85.7％ respectively when DWI was also used. Conclusions With whole-mount step-section pathology, the combination of MRI and DWI can improve the sensitivity of MRI for localized diagnosis in prostate cancer, especially in apex and mid parts of the prostate.