title: Low-field versus high-field MRI in diagnosing breast disorders.
abstract: We evaluated the performance of low-field MRI in breast disorders by comparing it with high-field MRI and biopsy results. Twenty-eight consecutive patients who were able to undergo two magnetic resonance examinations on following days were examined by high-field and low-field MRI. After T1-weighted sagittal images had been obtained a dynamic 3D axial study was performed followed by the acquisition of contrast-enhanced T1-weighted sagittal images. The images were analyzed separately by two radiologists paying attention to lesion morphology and enhancement kinetics. Six patients had problems in both breasts (34 breasts studied). The results were compared with biopsy results of 27 breasts. There were 16 malignant lesions, two fibroadenomas and nine other benign lesions. The inter-magnetic-resonance-scanner kappa value was 0.77 (substantial agreement), while the interobserver kappa value was 0.86 and 0.81 at low and high field, respectively (excellent agreement). The sensitivity was 100 and 100%, the specificity was 82 and 73% and the accuracy was 93 and 89% at low and high field, respectively. The mean lesion size was 2 cm and the smallest malignant lesion was 8 mm in diameter. Low-field MRI is a promising tool for breast imaging. Larger materials and smaller lesions are needed to evaluate its true sensitivity and specificity.
authors.affiliation: Department of Diagnostic Radiology, University of Oulu, Finland. eija.paakko@oulu.fi
authors.forename: Eija
authors.initials: E
authors.lastname: Pääkkö
authors.forename: Heli
authors.initials: H
authors.lastname: Reinikainen
authors.forename: Eija-Leena
authors.initials: EL
authors.lastname: Lindholm
authors.forename: Tarja
authors.initials: T
authors.lastname: Rissanen
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000473:pathology; D018275:Carcinoma, Lobular / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media; D005189:False Positive Reactions; D005240:Feasibility Studies; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis / Q000473:pathology; D005348:Fibrocystic Breast Disease / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media