Three-dimensional vascular mapping of the breast by using contrast-enhanced MRI: association of unilateral increased vascularity with ipsilateral breast cancer.

PURPOSE: We aimed to retrospectively compare three-dimensional vascular maps of both breasts obtained by dynamic magnetic resonance imaging (MRI) and determine the association of one-sided vascular prominence with ipsilateral breast cancer. MATERIALS AND METHODS: MRI was performed using gadolinium in 194 cases. Two readers scored vascular density using maximum intensity projections (MIPs). Dynamic fat-saturated T1-weighted gradientecho MIPs were acquired. Two readers evaluated the MIPs, and vessels greater than 2 mm in diameter and longer than 3 cm were counted. The difference in vessel numbers detected in the two breasts determined the score. RESULTS: A total of 54 patients had malignant lesions (prevalence, 28%), including invasive ductal carcinoma (n=40), invasive mixed ductal-lobular carcinoma (n=5), invasive lobular carcinoma (n=3), ductal carcinoma in situ (n=3), mucinous carcinoma (n=1), medullary carcinoma (n=1), and leukemic metastasis (n=1). In 62 patients, there were benign lesions (fibroadenomas, fibrocysts), and four patients had inflammation (granulomatous mastitis in two patients, breast tuberculosis in two patients). There were 78 normal cases. When a difference of at least two vessels was scored as vascular asymmetry, the sensitivity, specificity, positive likelihood ratio (+LR), and negative (-LR) of unilaterally increased vascularity associated with ipsilateral malignancy were 69%, 92%, 8.72, and 0.34, respectively. When four infection and three post-operative cases with vascular asymmetry were excluded; prevalence, specificity, and +LR increased to 29%, 97%, and 22.8, respectively, with the same sensitivity and -LR. Differences in mean vascularity scores were evaluated with regard to tumor size. T1 and T2 tumors were not significantly different from each other. The mean score of T3 tumors differed significantly from T1 and T2 tumors. CONCLUSION: MRI vascular mapping is an effective method for determining breast tissue vascularization. Ipsilateral increased vascularity was commonly associated with malignant breast lesions.