title: Diffusion-weighted magnetic resonance imaging in the differentiation of angiomyolipoma with minimal fat from clear cell renal cell carcinoma.
abstract: 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.
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Tanaka
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yoshida
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujii
authors.forename: Chikako
authors.initials: C
authors.lastname: Ishii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Koga
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Saito
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Masuda
authors.forename: Satoru
authors.initials: S
authors.lastname: Kawakami
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kihara
mesh_terms: D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000175:diagnosis* / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies