title: Evolutionary magnetic resonance appearance of renal cell carcinoma after percutaneous cryoablation.
abstract: OBJECTIVE
  To determine the evolutionary MRI appearance of renal cell carcinoma (RCC) following cryoablation.
  
  
  METHODS
  For this institution review board-approved study, we recruited patients with biopsy-proven RCC and treated them with percutaneous cryoablation between November 2009 and October 2014. Two radiologists retrospectively reviewed the pre-procedural and follow-up MRI. The findings included tumour sizes, signal intensities on T1 weighted imaging (T1WI), T2 weighted imaging (T2WI), diffusion-weighted imaging, apparent diffusion coefficient (ADC) map and contrast enhancement patterns. The ADC values of the tumours before and after treatment were measured.
  
  
  RESULTS
  A total of 26 patients were enrolled. The ablated tumours exhibited predominantly high signals on T1WI at 1-9-month follow-up (47.1% strong hyperintense at 3 months) and subsequently returned to being isointense. In T2WI, the signals of the ablated tumours were highly variable during the first 3 months and became strikingly hypointense after 6 months (58.3% strong hypointense at 6 months). Diffusion restriction was prominent during the first 3 months (lowest ADC: 0.62 ± 0.29 × 10(-3) mm(2) s(-1) at 1 month). Contrast enhancement persisted up to 6 months after the procedure. The residual enhancement gradually increased in the dynamic scan and was most prominent in the delay phase.
  
  
  CONCLUSIONS
  The MRI of the cryoablated renal tumour follows a typical evolutionary pattern.
  
  
  CONCLUSIONS
  Familiarity of practitioners with the normal post-cryoablation change of RCC on MRI can enable the early detection and prevention of tumour recurrence.
authors.affiliation: 1 Department of Radiology, Taipei Veterans General Hospital, Taipei City, Taiwan.|2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.
authors.forename: Han-Jui
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: 2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.|3 Department of Urology, Taipei Veterans General Hospital, Taipei City, Taiwan.
authors.forename: Hsiao-Jen
authors.initials: HJ
authors.lastname: Chung
authors.affiliation: 1 Department of Radiology, Taipei Veterans General Hospital, Taipei City, Taiwan.|2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.
authors.forename: Hsin-Kai
authors.initials: HK
authors.lastname: Wang
authors.affiliation: 1 Department of Radiology, Taipei Veterans General Hospital, Taipei City, Taiwan.|2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.
authors.forename: Shu-Huei
authors.initials: SH
authors.lastname: Shen
authors.affiliation: 2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.|3 Department of Urology, Taipei Veterans General Hospital, Taipei City, Taiwan.
authors.forename: Yen-Hwa
authors.initials: YH
authors.lastname: Chang
authors.affiliation: 1 Department of Radiology, Taipei Veterans General Hospital, Taipei City, Taiwan.|2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.
authors.forename: Chun-Ku
authors.initials: CK
authors.lastname: Chen
authors.affiliation: 2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.|4 Department of Radiology, Yonghe Cardinal Tien Hospital, New Taipei City, Taiwan.
authors.forename: Hsiao-Ping
authors.initials: HP
authors.lastname: Chou
authors.affiliation: 1 Department of Radiology, Taipei Veterans General Hospital, Taipei City, Taiwan.|2 National Yang-Ming University School of Medicine, Taipei City, Taiwan.
authors.forename: Yi-You
authors.initials: YY
authors.lastname: Chiou
mesh_terms: D055011:Ablation Techniques / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015641:Radiography, Interventional / Q000379:methods; D012189:Retrospective Studies; D047368:Tumor Burden