Department of Radiology, Indiana University School of Medicine, Indianapolis, 46202, USA.
AJR Am J Roentgenol. 2010 Feb;194(2):438-45. doi: 10.2214/AJR.09.3024.
The objective of our study was to assess the value of diffusion-weighted imaging in differentiating among the various subgroups of renal masses.
This retrospective study measured the apparent diffusion coefficients (ADCs) of renal masses. Malignant lesions were confirmed with surgical pathology results. Benign cystic lesions were stable without treatment for a minimum follow-up of 24 months.
There were 20 and 22 patients, respectively, with benign lesions (three abscess, 31 cysts) and malignant lesions (17 clear cell, five papillary, one chromophobe, and two transitional cell cancers). The malignant lesions were larger than the benign lesions (mean diameter, 4.2 vs 2.6 cm, respectively; p = 0.01, Student's t test). The ADC values of the benign lesions were significantly higher than those of the malignant lesions (mean, 2.72 vs 1.88 x 10(-3) mm(2)/s; p < 0.0001). The ADCs of the 31 benign cysts were significantly higher than those of the seven cystic renal cancers (2.77 vs 2.02 x 10(-3) mm(2)/s; p < 0.001). There was no significant difference between the ADCs of clear cell cancers and non-clear cell cancers (1.85 vs 1.97 x 10(-3) mm(2)/s; p = 0.18), but an ADC of less than 1.79 x 10(-3) mm(2)/s was seen only with clear cell cancer. The ADCs of high-grade clear cell cancers (Fuhrman grades III and IV) tended to be lower than those of low-grade clear cell cancers (1.77 vs 1.95 x 10(-3) mm(2)/s; p = 0.12). Among the clear cell cancers, an ADC value of greater than 2.12 x 10(-3) mm(2)/s was seen only with low-grade histology. For differentiating benign from malignant lesions, receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.989 (95% CI, 0.919-0.996; p < 0.0001).
ADC measurements may aid in differentiating among the various subgroups of renal masses, particularly benign cystic lesions from cystic renal cell cancers.
本研究旨在评估扩散加权成像在区分肾脏肿块的不同亚组中的价值。
本回顾性研究测量了肾脏肿块的表观扩散系数（ADC）。恶性病变通过手术病理结果证实。良性囊性病变在至少 24 个月的随访中保持稳定，无需治疗。
良性病变组分别有 20 例（3 例脓肿，31 例囊肿）和 22 例恶性病变（17 例透明细胞癌，5 例乳头状癌，1 例嫌色细胞癌和 2 例移行细胞癌）。恶性病变比良性病变大（平均直径分别为 4.2cm 和 2.6cm；p=0.01，Student's t 检验）。良性病变的 ADC 值明显高于恶性病变（平均分别为 2.72×10(-3)mm(2)/s 和 1.88×10(-3)mm(2)/s；p<0.0001）。31 例良性囊肿的 ADC 值明显高于 7 例囊性肾细胞癌（2.77×10(-3)mm(2)/s 和 2.02×10(-3)mm(2)/s；p<0.001）。透明细胞癌和非透明细胞癌的 ADC 值无显著差异（1.85×10(-3)mm(2)/s 和 1.97×10(-3)mm(2)/s；p=0.18），但仅见于透明细胞癌的 ADC 值小于 1.79×10(-3)mm(2)/s。高级别透明细胞癌（Fuhrman 分级 III 和 IV）的 ADC 值趋于低于低级别透明细胞癌（1.77×10(-3)mm(2)/s 和 1.95×10(-3)mm(2)/s；p=0.12）。在透明细胞癌中，仅在低级别组织学中观察到 ADC 值大于 2.12×10(-3)mm(2)/s。对于区分良性和恶性病变，受试者工作特征（ROC）分析显示 ROC 曲线下面积为 0.989（95%CI，0.919-0.996；p<0.0001）。
ADC 测量值可辅助区分肾脏肿块的不同亚组，尤其是良性囊性病变与囊性肾细胞癌。
