To evaluate the contrast enhancement and the optimal enhancement timing for contrast-enhanced cone-beam breast computed tomography (CE-CBBCT) in differentiating benign and malignant breast lesions.
Twenty-one subjects were enrolled under an Institutional Review Board approved study protocol, and had CE-CBBCT before biopsy and treatment. All subjects were female. They were between 36 and 68 years old with a median age of 52.2. The subjects received diagnostic mammography or ultrasound within two weeks and were categorized as BIRADS 4 or 5.The CE-CBBCT exam included one pre-contrast scan and two post-contrast scans (initiated at 40 seconds and 120 seconds from the start of injecting contrast material). Statistical analyses were performed in SPSS.
Twenty-four lesions（5 benign，19 malignant）in the 21 subjects were proved by pathology. Malignant lesions were enhanced by 34.7 HU±22.5 at 40 seconds and 74.5 HU±26.8 at 120 seconds ( P <0.001); Benign lesions were enhanced by 18.0 HU±9.5 at 40 seconds and 33.8 HU±11.0 at 120 seconds(P <0.05). Normal breast tissue was enhanced by 8.7 HU±7.7 and 12.9 HU±7.2, respectively at 40s and 120s (P<0 .001). Among the 21 subjects, mammography identified 10 subjects with mass, and 11 with asymmetry or architectural distortion. CE-CBBCT identified 17 subjects with mass and 4 with ductal and segmental enhancement. Lesion margins were more conspicuous on CE-CBBCT than mammography (p<0.05). All subjects were identified on CE-CBBCT. Eleven subjects with multiple lesions were not seen on mammography. 9 of them had lesions with diameters less than 1.5mm. The smallest lesion was 0.6mm.
Conclusions:Both benign and malignant lesions had more enhancements at 120s than 40s after the contrast injection. Malignant lesions had more enhancement compared to benign lesions. CE-CBBCT may improve the conspicuity of breast lesions, detect minimal disease in the case of multiple lesions, improve the early detection and diagnosis of breast cancer.