title: Radiographer technique: Does it contribute to the question of clip migration?
abstract: BACKGROUND
  Marker clips are commonly deployed at the site of a percutaneous breast biopsy. Studies have shown that displacement of the clip from the site of deployment is not uncommon. The objective of this study was to determine how much 'migration' could be seen with fixed structures within the breast tissue across three consecutive annual screening examinations, and therefore attempt to quantify how much of the reported clip migration could be due to radiographer technique.
  
  
  METHODS
  Large, easily identified benign calcifications were measured by two investigators across three consecutive cycles of screening mammography. The position of the calcifications on the two standard mammographic views was measured in two planes. Other variables recorded included breast size and density, compression force used, and location of the benign calcifications within the breast.
  
  
  RESULTS
  In 38% of cases, benign breast calcifications showed a mimicked movement of >15 mm in at least one plane. This was greatest in large breasts, those where fibroglandular tissue occupied less than 50% of the breast volume, and in the upper outer quadrant of the breast where mimicked movement >10 mm was noted in up to 90% of the larger breasts.
  
  
  CONCLUSIONS
  Fixed immobile objects in the breast can appear to move a distance of >15 mm in up to 30% of cases. Clinically, some of what has previously been called marker 'migration' may be spurious and accounted for by differences in radiographic positioning techniques.
authors.affiliation: Imaging Services Department, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Carolyn R
authors.initials: CR
authors.lastname: Madeley
authors.affiliation: Imaging Services Department, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Meredith Anita
authors.initials: MA
authors.lastname: Kessell
authors.affiliation: SEA Pty Ltd., Perth, Western Australia, Australia.
authors.forename: Chris J D
authors.initials: CJ
authors.lastname: Madeley
authors.affiliation: Imaging Services Department, Royal Perth Hospital, Perth, Western Australia, Australia.|University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Donna Blanche
authors.initials: DB
authors.lastname: Taylor
authors.affiliation: Imaging Services Department, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Elizabeth Jane
authors.initials: EJ
authors.lastname: Wylie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001941:Breast Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002983:Clinical Competence / Q000706:statistics & numerical data; D004867:Equipment Design; D005260:Female; D057918:Fiducial Markers / Q000009:adverse effects* / Q000706:statistics & numerical data; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008327:Mammography / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D015588:Observer Variation; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data; D015995:Prevalence; D011871:Radiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014904:Western Australia / Q000453:epidemiology
keywords: breast imaging; clip migration; mammography