Radiology: Volume 256: Number 3—September 2010
Nicolas D. Prionas, MS Karen K. Lindfors, MD Shonket Ray, MS Shih-Ying Huang, BS Laurel A. Beckett, PhD Wayne L. Monsky, MD, PhD John M. Boone, PhD
Purpose: To quantify contrast material enhancement of breast le-sions scanned with dedicated breast computed tomogra-phy (CT) and to compare their conspicuity with that at unenhanced breast CT and mammography.
Materials and Methods:Approval of the institutional review board and the Radiation Use Committee and written informed consent were obtained for this HIPAA-compliant study. Between September 2006 and April 2009, 46 women (mean age, 53.2 years; age range, 35-72 years) with Breast Imaging Reporting and Data System category 4 or 5 lesions underwent unenhanced breast CT and contrast material-enhanced breast CT before biopsy. Two radiologists independently scored lesion conspicuity for contrast-enhanced breast CT versus mammography and for contrast-enhanced breast CT versus unenhanced breast CT. Mean lesion voxel inten¬sity was measured in Hounsfield units and normalized to adipose tissue intensity on manually segmented images obtained before and after administration of contrast ma¬terial. Regression models focused on conspicuity and quantified enhancement were used to estimate the effect of pathologic diagnosis (benign vs malignant), lesion type (mass vs calcifications), breast density, and interradiologist variability.
Results: Fifty-four lesions (25 benign, 29 malignant) in 46 sub-jects were analyzed. Malignant lesions were seen sig-nificantly better at contrast-enhanced breast CT than at unenhanced breast CT (P < .001) or mammography (P < .001). Malignant calcifications (malignant lesions manifested mammographically as microcalcifications only, n = 7) were seen better at contrast-enhanced breast CT than at unenhanced breast CT (P < .001) and were seen similarly at contrast-enhanced breast CT and mammogra-phy. Malignant lesions enhanced 55.9 HU ± 4.0 (standard error), whereas benign lesions enhanced 17.6 HU ± 6.1 (P < .001). Ductal carcinoma in situ (n = 5) enhanced a mean of 59.6 HU ± 2.8. Receiver operating characteristic curve analysis of lesion enhancement yielded an area un-der the receiver operating characteristic curve of 0.876.
Conclusion: Conspicuity of malignant breast lesions, including ductal carcinoma in situ, is significantly improved at contrast-enhanced breast CT. Quantifying lesion enhancement may aid in the detection and diagnosis of breast cancer.