Department of Urology, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
Int J Urol. 2011 Oct;18(10):727-30. doi: 10.1111/j.1442-2042.2011.02824.x. Epub 2011 Aug 4.
The aim of the present study was to evaluate diffusion-weighted (DW) magnetic resonance imaging (MRI) in differentiating between minimal fat angiomyolipoma (MFAML) and clear cell renal cell carcinoma (CCRCC). Forty-one solid renal tumors without visible macroscopic fat on unenhanced computed tomography images were evaluated by MRI, including DW-MRI, and were diagnosed pathologically as CCRCC (n = 36) or MFAML (n = 5). To evaluate the heterogeneity of diffusion in each tumor, the signals of the tumors on DW-MRI were analyzed subjectively and the apparent diffusion coefficient (ADC) values and histograms assessed objectively. Thirty-three of 36 CCRCC (92%) exhibited a heterogeneous signal on DW-MRI and several peaks in the ADC value histogram, whereas four of five MFAML exhibited a homogeneous signal on DW-MRI and a single prominent peak in the histogram. The standard deviations of the ADC values were significantly smaller for MFAML than for CCRCC (P = 0.0015). In conclusion, DW-MRI can be considered a useful and noninvasive addition to the preoperative differentiation of CCRCC and MFAML.
本研究旨在评估扩散加权（DW）磁共振成像（MRI）在鉴别最小脂肪性血管平滑肌脂肪瘤（MFAML）和透明细胞肾细胞癌（CCRCC）中的作用。41 个实性肾脏肿瘤在未增强 CT 图像上未见明显肉眼脂肪，通过 MRI（包括 DW-MRI）进行评估，并经病理诊断为 CCRCC（n = 36）或 MFAML（n = 5）。为了评估每个肿瘤中扩散的异质性，对 DW-MRI 上肿瘤的信号进行了主观分析，并对表观扩散系数（ADC）值和直方图进行了客观评估。36 例 CCRCC 中有 33 例（92%）在 DW-MRI 上表现出不均匀信号和 ADC 值直方图中的多个峰，而 5 例 MFAML 中有 4 例在 DW-MRI 上表现出均匀信号和直方图中的单个突出峰。MFAML 的 ADC 值标准差明显小于 CCRCC（P = 0.0015）。总之，DW-MRI 可作为术前鉴别 CCRCC 和 MFAML 的一种有用且无创的附加方法。
