title: Background 99mTc-methoxyisobutylisonitrile uptake of breast-specific gamma imaging in relation to background parenchymal enhancement in magnetic resonance imaging.
abstract: OBJECTIVE
  This study investigated factors that could affect background uptake of (99m)Tc- methoxyisobutylisonitrile (MIBI) on normal breast by breast-specific gamma imaging (BSGI). In addition, the impact of background (99m)Tc-MIBI uptake on the diagnostic performance of BSGI was further investigated.
  
  
  METHODS
  One hundred forty-five women with unilateral breast cancer who underwent BSGI, MRI, and mammography were retrospectively enrolled. Background uptake on BSGI was evaluated qualitatively and quantitatively. Patients were classified into non-dense and dense breast groups according to mammographic breast density. Background parenchymal enhancement (BPE) was rated according to BI-RADS classification. The relationship of age, menopausal status, mammographic breast density, and BPE with background (99m)Tc-MIBI uptake was analyzed.
  
  
  RESULTS
  Heterogeneous texture and high background uptake ratio on BSGI were significantly correlated with younger age (p < 0.001, respectively), premenopausal status (p < 0.001 and p = 0.003), dense breast (p < 0.001, respectively), and marked BPE (p < 0.001, respectively). On multivariate analysis, only BPE remained a significant factor for background MIBI uptake (p < 0.001).There was a significant reduction in positive predictive value (p = 0.024 and p = 0.002) as background MIBI uptake and BPE grade increased.
  
  
  CONCLUSIONS
  BPE on MRI was the most important factor for background MIBI uptake on BSGI. High background MIBI uptake or marked BPE can diminish the diagnostic performance of BSGI.
  
  
  CONCLUSIONS
  • Age, menopause, density, and background parenchymal enhancement affect background MIBI uptake. • BPE is an independent factor for background MIBI uptake on BSGI. • Marked BPE may impair BSGI interpretation.
authors.affiliation: Department of Nuclear Medicine, Ewha Womans University, 911-1 Mok-Dong, Yangchun-Ku, Seoul, 158-710, Republic of Korea.
authors.forename: Hai-Jeon
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Yemi
authors.initials: Y
authors.lastname: Kim
authors.forename: Jee Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Bom Sahn
authors.initials: BS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi