Breast imaging: is the sonographic descriptor of orientation valid for magnetic resonance imaging?
OBJECTIVE
To evaluate if the Breast Imaging Reporting and Data System (BI-RADS) ultrasound descriptor of orientation can be used in magnetic resonance imaging (MRI).


METHODS
We conducted a retrospective study to evaluate breast mass lesions identified by MRI from 2008 to 2010 who had ultrasound (US) and histopathologic confirmation. Lesions were measured in the craniocaudal (CC), anteroposterior (AP), and transverse (T) axes and classified as having a nonparallel orientation, longest axis perpendicular to Cooper's ligaments, or in a parallel orientation when the longest axis is parallel to Cooper's ligaments. The MR image data were correlated with the US orientation according to BI-RADS and histopathological diagnosis.


RESULTS
We evaluated 71 lesions in 64 patients. On MRI, 27 lesions (38.0%) were nonparallel (8 benign and 19 malignant), and 44 lesions (62.0%) were parallel (33 benign and 11 malignant). There was significant agreement between the lesion orientation on US and MRI (kappa value = 0.901). The positive predictive values (PPV) for parallel orientation malignancy on MR and US imaging were 70.4% and 73.1%, respectively.


CONCLUSIONS
A descriptor of orientation for breast lesions can be used on MRI with PPV for malignant lesions similar to US.
Internal Medicine Department, Imaging and Medical Physics Center, Hospital Clinicas, Ribeirao Preto School of Medicine, University of Sao Paulo, Brazil. tatianemendes@yahoo.com.br
Tatiane M G
TM
Oliveira
Tatiana Kelly
TK
Brasileiro Sant'Anna
Fernando M
FM
Mauad
Jorge
J
Elias
Valdair F
VF
Muglia
D000465:Algorithms; D001943:Breast Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D056888:Patient Positioning / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods*