title: Contrast-enhanced sonography of postbiopsy arteriovenous fistulas in kidney grafts.
abstract: OBJECTIVE
  To assess the usefulness of contrast-enhanced ultrasonography (CE-US) in the visualization of a kidney graft following a biopsy that was complicated by an arteriovenous fistula (AVF).
  
  
  METHODS
  Four postrenal transplant patients who had developed AVFs following graft biopsy were examined using standard US and CE-US. Additionally, follow-up examinations were conducted using CE-US, at 4-6 weeks and 10-12 weeks following fistula closure.
  
  
  RESULTS
  The fistulas were detected using color Doppler US, Power Doppler US, and B-flow technique. Reduced parenchymal flow was only detected in one case using standard flow visualization techniques. CE-US allowed for the visualization of regions of disturbed parenchymal perfusion that were not visible in the standard examinations. At follow-up, B-mode ultrasound and standard flow examinations appeared normal. However, all contrast-enhanced images showed clearly demarcated residual regions of reduced parenchymal perfusion, in areas where the fistulas had been previously present.
  
  
  CONCLUSIONS
  A posttraumatic AVF reduces parenchymal perfusion in the affected region. CE-US examination may help in monitoring fistulas during the active phase and following spontaneous closure.
authors.affiliation: Department of Radiology and Diagnostic Imaging, Medical University of Lodz, Lodz, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Grzelak
authors.forename: M
authors.initials: M
authors.lastname: Sapieha
authors.forename: I
authors.initials: I
authors.lastname: Kurnatowska
authors.forename: M
authors.initials: M
authors.lastname: Nowicki
authors.forename: J
authors.initials: J
authors.lastname: Strzelczyk
authors.forename: L
authors.initials: L
authors.lastname: Stefańczyk
mesh_terms: D000328:Adult; D001164:Arteriovenous Fistula / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D001707:Biopsy, Needle / Q000009:adverse effects* / Q000379:methods; D003287:Contrast Media; D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D007089:Image Enhancement; D016030:Kidney Transplantation / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000009:adverse effects / Q000379:methods; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000473:pathology; D012082:Renal Veins / Q000000981:diagnostic imaging / Q000473:pathology; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color
chemical_list: D003287:Contrast Media