title: The effects of applying breast compression in dynamic contrast material-enhanced MR imaging.
abstract: OBJECTIVE
  To evaluate the effects of breast compression on breast cancer masses, contrast material enhancement of glandular tissue, and quality of magnetic resonance (MR) images in the identification and characterization of breast lesions.
  
  
  METHODS
  This was a HIPAA-compliant, institutional review board-approved retrospective study, with waiver of informed consent. Images from 300 MR imaging examinations in 149 women (mean age ± standard deviation, 51.5 years ± 10.9; age range, 22-76 years) were evaluated. The women underwent diagnostic MR imaging (no compression) and MR-guided biopsy (with compression) between June 2008 and February 2013. Breast compression was expressed as a percentage relative to the noncompressed breast. Percentage enhancement difference was calculated between noncompressed- and compressed-breast images obtained in early and delayed contrast-enhanced phases. Breast density, lesion type (mass vs non-masslike enhancement [NMLE]), lesion size, percentage compression, and kinetic curve type were evaluated. Linear regression, receiver operating characteristic (ROC) curve analysis, and κ test were performed.
  
  
  RESULTS
  Mean percentage compression was 31.3% ± 9.2 (range, 5.8%-53.2%). Percentage enhancement was higher in noncompressed- versus compressed-breast studies in early (146% ± 66 vs 107% ± 42, respectively; P < .001) and delayed (158% ± 68 vs 107% ± 42, respectively; P = .1) phases. Among breast lesions, 12% (seven of 59) were significantly smaller when compressed, which led to underestimation of TNM classification (P < .001). Breast masses (n = 35) showed significantly higher early percentage enhancement (157% ± 71) than lesions with NMLE (n = 15, 120% ± 40; P = .02) and a percentage enhancement difference (47.5% ± 64 vs 17% ± 28, respectively; P = .023). Kinetic curve performance for identifying invasive cancer decreased after compression (area under ROC curve = 0.53 vs 0.71, respectively; P = .02). Breast compression resulted in complete loss of enhancement of nine of 210 lesions (4%).
  
  
  CONCLUSIONS
  Breast compression during biopsy affected breast lesion detection, lesion size, and dynamic contrast-enhanced MR imaging interpretation and performance. Limiting the application of breast compression is recommended, except when clinically necessary.
authors.affiliation: From The Russell H. Morgan Department of Radiology and Radiological Sciences (R.H.E.K., K.J.M., I.R.K., D.A.B., M.A.J.) and Sidney Kimmel Comprehensive Cancer Center (M.A.J.), The Johns Hopkins University School of Medicine, 600 N Wolfe St, MRI 110 Central Radiology, Baltimore, MD 21287; Department of Diagnostic Radiology, Suez Canal University Faculty of Medicine, Ismailia, Egypt (R.H.E.K.); and Department of Radiology and Imaging Sciences, National Institutes of Health, Bethesda, Md (D.A.B.).
authors.forename: Riham H
authors.initials: RH
authors.lastname: El Khouli
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Macura
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Michael A
authors.initials: MA
authors.lastname: Jacobs
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019245:Compressive Strength; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds; D011312:Pressure; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine