Magnetic resonance imaging of the breast prior to biopsy.
BACKGROUND
Breast magnetic resonance imaging (MRI) has been shown to have high sensitivity for cancer detection and is increasingly used following mammography to evaluate suspicious breast lesions.


OBJECTIVE
To determine the accuracy of breast MRI in conjunction with mammography for the detection of breast cancer in patients with suspicious mammographic or clinical findings.


METHODS
Prospective multicenter investigation of the International Breast MR Consortium conducted at 14 university hospitals in North America and Europe from June 2, 1998, through October 31, 2001, of 821 patients referred for breast biopsy for American College of Radiology category 4 or 5 mammographic assessment or suspicious clinical or ultrasound finding.


METHODS
MRI examinations performed prior to breast biopsy; MRI results were interpreted at each site, which were blinded to pathological results.


METHODS
Area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of breast MRI.


RESULTS
Among the 821 patients, there were 404 malignant index lesions, of which 63 were ductal carcinoma in situ (DCIS) and 341 were invasive carcinoma. Of the 417 nonmalignant index lesions, 366 were benign, 47 showed atypical histology, and 4 were lobular carcinoma in situ. The AUC pooled over all institutions was 0.88 (95% confidence interval [CI], 0.86-0.91). MRI correctly detected cancer in 356 of 404 cancer cases (DCIS or invasive cancer), resulting in a sensitivity of 88.1% (95% CI, 84.6%-91.1%), and correctly identified as negative for cancer 281 of 417 cases without cancer, resulting in a specificity of 67.7% (95% CI, 62.7%-71.9%). MRI performance was not significantly affected by mammographic breast density, tumor histology, or menopausal status. The positive predictive values for 356 of 492 patients was 72.4% (95% CI, 68.2%-76.3%) and of mammography for 367 of 695 patients was 52.8% (95% CI, 49.0%-56.6%) (P<.005). Dynamic MRI did not improve the AUC compared with 3-dimensional MRI alone, but the specificity of a washout pattern for 123 of 136 patients without cancer was 90.4% (95% CI, 84%-95%).


CONCLUSIONS
Breast MRI has high sensitivity but only moderate specificity independent of breast density, tumor type, and menopausal status. Although the positive predictive value of MRI is greater than mammography, MRI does not obviate the need for subsequent tissue sampling in this setting.
Bluemke
David A
DA
Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Md, USA. dbluemke@jhmi.edu
Gatsonis
Constantine A
CA
Chen
Mei Hsiu
MH
DeAngelis
Gia A
GA
DeBruhl
Nanette
N
Harms
Steven
S
Heywang-Köbrunner
Sylvia H
SH
Hylton
Nola
N
Kuhl
Christiane K
CK
Lehman
Constance
C
Pisano
Etta D
ED
Causer
Petrina
P
Schnitt
Stuart J
SJ
Smazal
Stanley F
SF
Stelling
Carol B
CB
Weatherall
Paul T
PT
Schnall
Mitchell D
MD
D000328:Adult; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity