title: Diffusion-weighted magnetic resonance imaging in focal breast lesions: analysis of 78 cases with pathological correlation.
abstract: OBJECTIVE
  This study assessed the usefulness of magnetic resonance diffusion-weighted imaging (DWI) in distinguishing between benign and malignant breast lesions.
  
  
  METHODS
  Gadolinium-enhanced magnetic resonance imaging (MRI) and DWI with determination of the apparent diffusion coefficient (ADC) were performed on 78 women, each with a focal breast lesion at least 7 mm in diameter, which was studied by cytology or histology.
  
  
  RESULTS
  Final diagnoses were obtained by cytology in 29 cases and histology in 49 (11 percutaneous biopsies and 38 surgical specimens). There were 43 benign lesions (13 fibrocystic disease, eight fibroadenoma, seven adenosis, five normal breast tissue, four inflammatory lesions, three intramammary lymph nodes, two scleroelastosis and one fat necrosis) and 35 malignant lesions (30 invasive ductal carcinoma, two invasive lobular carcinoma, one ductal carcinoma in situ, one carcinomatous mastitis and one metastasis from neuroendocrine carcinoma). The mean ADC values were 1.677±0.151 for benign lesions and 1.298±0.129 for malignant lesions (p<0.001). With an ADC cutoff value of 1.48, DWI had 88.6% sensitivity [confidence interval (CI) 78.1%-99.1%] and 95.3% specificity (CI 88.9%-100%), with 31 true positives, four false negatives (three invasive ductal carcinoma and one carcinomatous mastitis), 41 true negatives and two false positives (one fat necrosis and one fibroadenoma). With the cutoff value set at 1.52, DWI sensitivity (35 true positive, no false negative) was 100% and specificity was 86% (CI 75.7%-96.3%) due to 37 true negatives and six false positives (an additional two fibroadenoma and two fibrocystic disease compared with those recorded with the cutoff set at 1.48). The overall accuracy of DWI considering both cutoff values (72 correct evaluations out of 78 cases) was 92.3% (CI 86.4%-98.2%).
  
  
  CONCLUSIONS
  DWI is a reliable tool for characterising focal breast lesions.
authors.affiliation: Department of Radiology, Ospedale Scaligero Veronese, Via Fontanelle, 1, 37047, S. Bonifacio, Verona, Italy. francescafornasa@libero.it
authors.forename: F
authors.initials: F
authors.lastname: Fornasa
authors.forename: L
authors.initials: L
authors.lastname: Pinali
authors.forename: A
authors.initials: A
authors.lastname: Gasparini
authors.forename: E
authors.initials: E
authors.lastname: Toniolli
authors.forename: S
authors.initials: S
authors.lastname: Montemezzi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D001941:Breast Diseases / Q000175:diagnosis* / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine