title: Clinical use of renal perfusion imaging by means of harmonic sonography with a microbubble contrast agent in patients after renal transplantation: preliminary study.
abstract: OBJECTIVE
  The purpose of this research was to determine the feasibility of renal perfusion imaging by means of harmonic sonography with a microbubble contrast agent for the evaluation of renal perfusion after renal transplantation compared with technetium Tc 99m diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) scans.
  
  
  METHODS
  During a 10-month period, 100 patients with renal transplantation that included normal perfusion (n=68) and delayed perfusion including chronic rejection (n=19), acute rejection (n=9), arterial stenosis (n=2), and urinary stricture (n=2) underwent sonographic renal perfusion imaging and (99m)Tc-DTPA scans. Sonographic images were obtained every 3 seconds for a total of 3 minutes after administration of a bolus injection of 4 g of the microbubble contrast agent at a concentration of 300 mg/mL. Sonographic renal perfusion images were converted into a renal perfusion curve, and the calculated time at the peak of the curve (T(peak)) was compared with that of the (99m)Tc-DTPA scan.
  
  
  RESULTS
  The T(peak) with the (99m)Tc-DTPA scan was 14.9 seconds in the normal group and 33 seconds in the delayed perfusion group. The T(peak) on sonographic renal perfusion images was 25 seconds in the normal group and 44.8 seconds in the delayed perfusion group. Sonographic renal perfusion images showed good correlation with the (99m)Tc-DTPA scan (r=0.74; P=.0001). The cutoff value of the T(peak) on sonographic renal perfusion images was 35 seconds (sensitivity=85%; specificity=90%).
  
  
  CONCLUSIONS
  The renal perfusion images obtained by means of harmonic sonography with a microbubble contrast agent constitute an effective sonographic technique for the evaluation of renal perfusion abnormalities after renal transplantation compared with a (99m)Tc-DTPA scan.
authors.affiliation: Department of Radiology, Soonchunhyang University Hospital, 657 Hannam-Dong, Youngsan-Ku, Seoul 140-743, Korea. junghkim@hosp.sch.ac.kr
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Hyo Won
authors.initials: HW
authors.lastname: Eun
authors.forename: Hun Jae
authors.initials: HJ
authors.lastname: Lee
authors.forename: Dong Erk
authors.initials: DE
authors.lastname: Goo
authors.forename: Deuk Lin
authors.initials: DL
authors.lastname: Choi
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D012372:ROC Curve; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate
chemical_list: D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate