Comparison of enhancement characteristics between invasive lobular carcinoma and invasive ductal carcinoma

Purpose: To compare enhancement characteristics between invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) on contrast enhanced MRI of the breast and to observe the magnitude of eventual differences as these may impair the diagnostic value of breast MRI in ILC. Materials and Methods: We performed an analysis of enhancement characteristics on biphasic breast MRI in a series of 136 patients (103 IDC, 33 ILC) using an in-house developed application for pharmacokinetic modeling of contrast enhancement and a commercially available CAD application that evaluated the contrast-enhancement versus time curve. Results: Pharmacokinetic analysis showed that the most enhancing voxels in IDC had significantly higher K ^trans-values than in ILC (P < 0.01). No difference in v _e-values was noted between groups. Visual assessment of contrast-enhancement versus time curves revealed wash-out curves to be less common in ILC (48% versus 84%). However, when using the CAD-application to assess the most malignant looking curve, the difference was blotted out (76% versus 86%). Conclusion: ILC enhances slower than IDC but peak enhancement is not significantly less. The use of a CAD-application may help to determine the most malignant looking contrast-enhancement versus time curve, and hence facilitates lesion classification.