Role of MR Spectroscopy in Characterization of Breast Masses

Abstract

Introduction: Dynamic contrast enhanced magnetic resonance imaging “MRI” is not 100 percent accurate in distinguishing benign from malignant lesions, resulting in a large number of breast biopsy procedures recommended on the basis of imaging findings. Proton magnetic resonance spectroscopy “¹H MRS” can provide chemical information about a lesion by measuring the levels of choline compounds, which are markers of an active tumor. In most cases, the results indicate whether the lesion is cancerous without need for biopsy. In addition to being used in breast cancer diagnosis, in vivo ¹H MRS has also been used to monitor breast cancer response to chemotherapy as well as in differentiating between scar tissue and recurrent cancer after breast-conserving therapy. Aim of the work: To evaluate the diagnostic performance of magnetic resonance spectroscopy “MRS” in characterization of breast masses with histopathologic findings or follow up used as the reference standard. Methods: The studied group included 50 female patients referred for MRI breast for workup of a suspicious clinical, mammographic, or sonographic abnormality. ¹H MRS was added to the routine study. Results of the contrast enhanced bilateral breast MRI and ¹H MRS of the 50 patients were all reported and compared with the histo-pathological results of surgery or biopsy and with the results of follow up of lesions that were not surgically removed or biopsied. Results: there was a highly significant relation between ¹H MRS and histopathological. Follow Up results with p value = 0.005. The sensitivity, specificity, positive and negative predictive values of ¹H MRS for characterization of suspicious breast lesions in patients included in the study, were 90%, 93.3%, 90%, and 93.3% respectively. Conclusion: ¹H MRS is a short non-invasive scan that can be inserted easily into standard clinical breast MRI protocols as a potential adjunct that can be added routinely to conventional breast MRI. Detection of choline peak with estimation of the choline signal to noise ratio “SNR” can accurately differentiate benign from malignant breast lesions with high sensitivity and specificity especially when its results are combined with the results of the standard dynamic MRI scan.