title: The potential role of modern US in the follow-up of patients with retroperitoneal fibrosis.
abstract: OBJECTIVE
  We aimed to evaluate a standardized ultrasonography (US) algorithm for the visualization of pathologic para-aortic tissue in retroperitoneal fibrosis (RPF).
  
  
  METHODS
  Thirty-five patients with lumbar RPF of typical extent, as determined by abdominal magnetic resonance imaging, were included. Examinations were conducted using standardized abdominal US with axial sections obtained at the levels of the renal arteries, aortic bifurcation, and both common iliac arteries. Imaging of each section was acquired with fundamental B-mode (US) and tissue harmonic imaging, respectively. In addition, we examined RPF visualized using extended field-of-view US.
  
  
  RESULTS
  Tissue harmonic imaging adequately visualized RPF of typical extent in 33 patients (94.2%). Excellent and good visualization with mild artifacts were achieved in 25 (71.4%) and six (17.1%) patients, respectively. When RPF spread along the iliac arteries, excellent visualization was achieved in 38.7% for the left side and 34.5% for the right side. There were significantly fewer diagnostic examinations for the right iliac (27.6%) than for the left one (9.7%) (P = 0.016). Overall, harmonic imaging achieved significantly better visualization than fundamental B-Mode (P < 0.001).
  
  
  CONCLUSIONS
  We described the first systematic evaluation of RPF visualization by modern US techniques. The best imaging quality was found in the typical RPF location, at the level of the aortic bifurcation. These results advocate for the presented US algorithm as an efficient follow-up alternative to cross-sectional imaging in RPF patients.
authors.affiliation: From the Departments of Diagnostic and Interventional Radiology (L.K. e-mail: lars.kamper@helios-kliniken.de, H.E., P.H., W.P.), and Urology (A.S.B., S.R.), HELIOS Medical Center Wuppertal, University Hospital Witten/Herdecke, Wuppertal, Germany; the Dean`s Office (M.H.), Department of Medical Education, Heinrich-Heine University Medical Faculty, Duesseldorf, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Kamper
authors.forename: Alexander Sascha
authors.initials: AS
authors.lastname: Brandt
authors.forename: Hendrik
authors.initials: H
authors.lastname: Ekamp
authors.forename: Matthias
authors.initials: M
authors.lastname: Hofer
authors.forename: Stephan
authors.initials: S
authors.lastname: Roth
authors.forename: Patrick
authors.initials: P
authors.lastname: Haage
authors.forename: Werner
authors.initials: W
authors.lastname: Piroth
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012185:Retroperitoneal Fibrosis / Q000000981:diagnostic imaging*; D014463:Ultrasonography