Department of Radiology, New York University Langone Medical Center, 560 First Ave., TCH-HW202, New York, NY 10016, USA.
AJR Am J Roentgenol. 2011 Jan;196(1):123-9. doi: 10.2214/AJR.10.4738.
The purpose of our study was to compare the visibility of prostate cancer on trace diffusion-weighted (DW) images and the apparent diffusion coefficient (ADC) map.
In this retrospective study, 45 patients with prostate cancer underwent preoperative MRI, including DW imaging (DWI) (b values 0, 500, and 1,000 s/mm(2)). A single observer reviewed the images in conjunction with tumor maps constructed from prostatectomy. For 132 peripheral zone (PZ) tumor foci, the visibility and contrast relative to benign PZ were recorded for T2-weighted imaging, trace DWI b500 images, trace DWI b1,000 images, and ADC maps. Trace DWI b1,000 images and ADC maps were compared in terms of Gleason score, size, normalized T2 signal intensity, ADC, and normalized ADC of visible tumors.
For each image set, the percentage of visible tumor foci and contrast relative to benign PZ were as follows: T2-weighted imaging, 80.3% and 0.411; trace DWI b500, 26.5% and 0.131; trace DWI b1,000, 46.2% and 0.119; and ADC maps, 62.1% and 0.309. Forty-seven tumor foci were visible on both trace DWI b1,000 images and ADC maps, 14 only on trace DWI b1,000 images, 35 only on ADC maps, and 36 on neither image set. There was no significant difference in Gleason score, size, normalized T2 signal intensity, ADC, or normalized ADC between tumors visible only on trace DWI b1,000 images and those visible only on ADC maps.
Given a greater proportion of tumors visible on the ADC map than trace DWI and greater contrast relative to benign PZ on the ADC map, we suggest that, when performing DWI of the prostate, careful attention be given to the ADC map for tumor identification.
本研究旨在比较前列腺癌在 trace 扩散加权（DW）图像和表观扩散系数（ADC）图上的可视性。
在这项回顾性研究中，45 例前列腺癌患者接受了术前 MRI 检查，包括 DW 成像（DWI）（b 值为 0、500 和 1000 s/mm²）。一位观察者结合前列腺切除术构建的肿瘤图回顾性分析图像。对于 132 个外周带（PZ）肿瘤灶，记录 T2 加权成像、trace DWI b500 图像、trace DWI b1000 图像和 ADC 图上肿瘤的可视性和对比。比较 trace DWI b1000 图像和 ADC 图在 Gleason 评分、大小、归一化 T2 信号强度、ADC 和可见肿瘤的归一化 ADC 方面的差异。
对于每个图像集，可见肿瘤灶的百分比和与良性 PZ 的对比如下：T2 加权成像，80.3%和 0.411；trace DWI b500，26.5%和 0.131；trace DWI b1000，46.2%和 0.119；ADC 图，62.1%和 0.309。47 个肿瘤灶在 trace DWI b1000 图像和 ADC 图上均可见，14 个仅在 trace DWI b1000 图像上可见，35 个仅在 ADC 图上可见，36 个在两个图像集上均不可见。仅在 trace DWI b1000 图像上可见的肿瘤和仅在 ADC 图上可见的肿瘤在 Gleason 评分、大小、归一化 T2 信号强度、ADC 或归一化 ADC 方面无显著差异。
由于 ADC 图上可见肿瘤的比例大于 trace DWI，并且相对于良性 PZ 的对比度更大，因此我们建议在进行前列腺 DWI 时，应仔细关注 ADC 图以识别肿瘤。
