title: Technical inadequacies of peripheral contrast-enhanced magnetic resonance angiography: incidence, causes and management strategies.
abstract: OBJECTIVE
  To assess the incidence, causes and effects of technical inadequacies in peripheral contrast-enhanced magnetic resonance angiography (CE-MRA) and to discuss relevant management strategies.
  
  
  METHODS
  A retrospective analysis of 249 peripheral CE-MRA examinations was performed using the radiology department's RIS/PACS (radiology information system/picture archiving and communication system) database. All failed or technically inadequate MRAs were reviewed. In cases that underwent further imaging by conventional angiography (CA), we assessed if relevant arterial disease had been masked on the MRA.
  
  
  RESULTS
  Of the 249 examinations, 215 (86.3%) were technically satisfactory while 34 (13.7%) were a combination of technical inadequacies [29 cases (11.6%)] and examination failures [five cases (2%)]. The causes of technical inadequacies were: (1) venous contamination (13 cases; 5.2%), (2) motion-induced subtraction artefact (eight cases; 3.2%), (3) stent-induced artefact (four cases; 1.6%), (4) inadequate scan coverage (two cases; 0.8%), and (5) contrast timing error (two cases; 0.8%). The causes of failed examinations were: (1) inability to tolerate lying in the scanner (three cases; 1.2%) and (2) inability to fit into the scanner (two cases; 0.8%). Fifteen (44.1%) of the 34 cases underwent further imaging by CA, and in eight of these there was significant arterial disease that was missed on the MRA.
  
  
  CONCLUSIONS
  Technical inadequacies occur in a small but significant proportion of peripheral CE-MRAs and can mask significant arterial disease. Knowledge of the potential causes of technical problems and the relevant management options is important for quality assurance and for limiting the need for an alternative investigation.
authors.affiliation: Department of Radiology, Hairmyres Hospital, East Kilbride, UK.
authors.forename: G
authors.initials: G
authors.lastname: Low
authors.forename: A
authors.initials: A
authors.lastname: Mizzi
authors.forename: K
authors.initials: K
authors.lastname: Ong
authors.forename: P F
authors.initials: PF
authors.lastname: Lau
authors.forename: J
authors.initials: J
authors.lastname: McKinstery
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries; D016477:Artifacts; D003287:Contrast Media; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015607:Stents; D014680:Veins
chemical_list: D003287:Contrast Media