title: Breast cancer detection using double reading of unenhanced MRI including T1-weighted, T2-weighted STIR, and diffusion-weighted imaging: a proof of concept study.
abstract: OBJECTIVE
  The purpose of this study was to investigate the diagnostic performance of unenhanced MRI in detecting breast cancer and to assess the impact of double reading.
  
  
  METHODS
  A total of 116 breasts of 67 women who were 36-89 years old were studied at 1.5 T using an unenhanced protocol including axial T1-weighted gradient-echo, T2-weighted STIR, and echo-planar diffusion-weighted imaging (DWI). Two blinded readers (R1 and R2) independently evaluated unenhanced images using the BIRADS scale. A combination of pathology and negative follow-up served as the reference standard. McNemar and kappa statistics were used.
  
  
  RESULTS
  Per-breast cancer prevalence was 37 of 116 (32%): 30 of 37 (81%) invasive ductal carcinoma, five of 37 (13%) ductal carcinoma in situ, and two of 37 (6%) invasive lobular carcinoma. Per-breast sensitivity of unenhanced MRI was 29 of 37 (78%) for R1, 28 of 37 (76%) for R2, and 29 of 37 (78%) for double reading. Specificity was 71 of 79 (90%) for both R1 and R2 and 69 of 79 (87%) for double reading. Double reading did not provide a significant increase in sensitivity. Interobserver agreement was almost perfect (Cohen κ = 0.873).
  
  
  CONCLUSIONS
  An unenhanced breast MRI protocol composed of T1-weighted gradient echo, T2-weighted STIR, and echo-planar DWI enabled breast cancer detection with sensitivity of 76-78% and specificity of 90% without a gain in sensitivity from double reading.
authors.affiliation: 1 Unit of Radiology, IRCCS Policlinico San Donato, Milan, Italy.
authors.forename: Rubina M
authors.initials: RM
authors.lastname: Trimboli
authors.forename: Nicola
authors.initials: N
authors.lastname: Verardi
authors.forename: Francesco
authors.initials: F
authors.lastname: Cartia
authors.forename: Luca A
authors.initials: LA
authors.lastname: Carbonaro
authors.forename: Francesco
authors.initials: F
authors.lastname: Sardanelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001943:Breast Neoplasms / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method
chemical_list: D003287:Contrast Media
keywords: MRI; breast cancer; diffusion-weighted imaging (DWI); double reading; sensitivity; specificity