Value of MRI Perfusion in Discrimination between Benign and Malignant Breast Masses, EMAN ABO EL-HAMD AHMED, NAGHAM N. MAHMOUD and SAMAA M. MOHAMMED
Abstract
Objective: Lesion detection at contrast material-enhanced breast Magnetic Resonance (MR) imaging is primarily based on a lesion's vascularity relative to normal breast tissue. MR imaging may be still be advantageous because it can be used not only to characterize the lesion in question but also to evaluate the remainder of the breast, potentially leading to identification of unsuspected multifocal disease. The primary benefit of a noninvasive test such as MR imaging undertaken prior to tissue diagnosis (i.e., with core biopsy or excisional biopsy) is that it can be used to determine which lesions are likely to be benign, so that mammographic or clinical follow-up could be used in place of tissue diagnosis. When a test is used in this capacity, it must be sufficiently sensitive that the negative predictive value is very high without sacrificing specificity. Standard evaluation criteria have not been optimized for evaluating Dynamic Contrast Enhanced breast MRI (DCE-MRI). Most evaluation criteria, especially morphologic criteria and Time-Intensity Curve (TIC) type, are subjectively inter-preted. To reduce the subjectivity, quantitative analysis of the perfusion parameters may be of value in differentiation between benign and malignant breast lesions which is the aim of this study.
Material and Methods: 46 female patients (50 lesions), who underwent breast DCE-MRI. The lesions were analyzed using computer-assisted diagnosis CAD software to reproduce qualitative and quantitative kinetic data and the results corre-lated with histopathological results.
TIC of dynamic images were generated using (CAD) software. Seven parameters were calculated: Maximal contrast enhancement (ME), Maximum Relative Enhancement (MRE), Time to Peak (TTP), wash in rate, wash out rate, brevity of enhancement and Area Under the Curve (AUC).
Results: Fifty lesions were analyzed, thirty three (68.2%) of them were malignant and 17 (31.8%) were benign as proved by histopathology. Cut-off values used for differentiation between benign and malignant lesions show highest sensitivity for TTP and wash out rate about 83.3 3% and 80% respectively. The highest specificity was detected for wash out rate and MRE being 82.4% and 94.1%.
Conclusion: The routine DCE-MRI protocol can derive a qualitative assessment of kinetic curve type with high sensitivity for malignancy and reliable quantitative parameter (TTP, wash in rate and wash out rate) for better characterization of benign and malignant breast lesions with significantly higher specificity and overall diagnostic performance.