title: Contrast-enhanced ultrasonography in the follow-up of cryoablation of renal tumours: a feasibility study.
abstract: OBJECTIVE
  To determine whether evaluating perfusion patterns with contrast-enhanced ultrasonography using contrast-pulse sequence imaging (CPS; a new imaging method that enables selective visualization of perfusion) is possible at different times after cryoablation of renal tumours, and to describe the characteristics of CPS in a small group of patients.
  
  
  METHODS
  The efficacy of renal cryoablation is mainly judged using imaging. Seven randomly selected patients, each at a different time after laparoscopically assisted cryoablation of a renal tumour, were investigated with CPS and a microbubble-contrast agent. The perfusion characteristics in the lesions were scored by two investigators and described, and the lesions were measured.
  
  
  RESULTS
  In the seven patients treated with cryoablation for small renal tumours, eight CPS studies were performed. Five lesions showed no enhancement and one lesion, investigated 18 months after treatment was not recognized. In one patient, no enhancement was seen after 1 month but 7 months later, there were minimal contrast signals inside the treated area. The lesions could be measured with a mean standard deviation of 1.1 mm and a mean difference between the two investigators of 0.7 mm.
  
  
  CONCLUSIONS
  Our first experiences with CPS imaging for the follow-up of renal cryoablation show that this technique can be used to characterize perfusion defects at different times after cryoablation.
authors.affiliation: Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Margot H
authors.initials: MH
authors.lastname: Wink
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Laguna
authors.forename: Brunolf W
authors.initials: BW
authors.lastname: Lagerveld
authors.forename: Jean J M C H
authors.initials: JJ
authors.lastname: de la Rosette
authors.forename: Hessel
authors.initials: H
authors.lastname: Wijkstra
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000601:surgery; D003287:Contrast Media; D003452:Cryosurgery / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D003287:Contrast Media