title: [CT differentiation of renal angiomyolipoma and renal cell carcinoma].
abstract: OBJECTIVE
  To improve the diagnosis of atypical renal angiomyolipoma (RAML) by use of CT to differentiate RAML from renal cell carcinoma (RCC).
  
  
  METHODS
  We retrospectively analyzed the CT manifestations with dual-phase enhanced contrast study in 36 cases of RAML (with 57 lesions) and 46 cases of RCC. 25 lesions of RAML and all RCC were histologically confirmed. Maximum likehood estimator was employed to discriminate all the lesions according to a series of indexes with statistical meanings.
  
  
  RESULTS
  Nine indexes were found to be significant and evident for separating RAML from RCC, namely "single or multiple", border, lobulation, protrusion rate, interface with cortex, angle with cortex, "levering-cortex-up" sign, characters of blood vessel in lesion and calcification. The accuracy rates of discrimination analysis for RAML and RCC were 93.0% and 89.1%, separately.
  
  
  CONCLUSIONS
  The importance of 4 indexes, including protrusion rate, angle with cortex, "levering-cortex-up" sign and the traits of blood vessel, should be highlighted in the differentiation of RAML and RCC.
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.forename: Rong-bo
authors.initials: RB
authors.lastname: Liu
authors.forename: Xiang-ping
authors.initials: XP
authors.lastname: Zhou
authors.forename: Zhi-feng
authors.initials: ZF
authors.lastname: Wu
authors.forename: Chun-yan
authors.initials: CY
authors.lastname: Lu
authors.forename: Na
authors.initials: N
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000000981:diagnostic imaging*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed