title: Peripheral bolus-chase MR angiography: analysis of risk factors for nondiagnostic image quality of the calf vessels--a combined retrospective and prospective study.
abstract: OBJECTIVE
  The objective of our study was to evaluate the influence of endogenous and exogenous risk factors on the rate of nondiagnostic examinations of the calves in peripheral bolus-chase MR angiography (MRA).
  
  
  METHODS
  Peripheral bolus-chase MRA runoff studies in 177 patients with peripheral arterial occlusive disease (PAOD) were retrospectively assessed with regard to the rate of nondiagnostic image quality due to substantial venous overlay in the calf arteries requiring repeated MRA examinations. Logistic regression was used to analyze the rate of nondiagnostic MRA examinations as a function of several endogenous and exogenous risk factors and of the stage of PAOD. To probe the retrospective data, 22 consecutive patients were prospectively included and underwent a standard peripheral MRA examination if the probability of a nondiagnostic examination was less than 50% based on the results of logistic regression; otherwise, a hybrid MRA examination was ordered.
  
  
  RESULTS
  Nondiagnostic image quality of the calf arteries was found in 53 patients (30%). The incidence increased with each stage of PAOD up to 39% for stage IV. For each increase in the stage of PAOD, the probability of nondiagnostic image quality increased by a factor of 1.5561 (p = 0.0024). With an increasing number of risk factors, a significantly (p = 0.0074) higher rate of nondiagnostic images was found.
  
  
  CONCLUSIONS
  Based on the retrospective statistical analysis of PAOD stages and risk factors, selected patients can be triaged to undergo a specific hybrid MRA technique and thus circumvent the occurrence of nondiagnostic images and the need for repeated MRA examinations.
authors: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty of Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
authors: Dietmar J
authors: DJ
authors: Dinter
authors: K Wolfgang
authors: KW
authors: Neff
authors: Giovanni
authors: G
authors: Visciani
authors: Ricarda
authors: R
authors: Lachmann
authors: Christel
authors: C
authors: Weiss
authors: Stefan O
authors: SO
authors: Schoenberg
authors: Henrik J
authors: HJ
authors: Michaely
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D003287:Contrast Media; D005260:Female; D005858:Germany; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000706:statistics & numerical data*; D008297:Male; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013848:Thigh / Q000098:blood supply* / Q000473:pathology*
chemical_list: D003287:Contrast Media