Value OF COMBINED MR PERFUSION AND MR SPECTROSCOPYIN CHARACTERIZATION OF SUSPICIOUS BREAST MASSES

Abstract

SUMMARY AND CONCLUSION M RI has been confirmed as an essential tool for examination of the breasts because of its remarkably higher sensitivity with the use of enhancement material for breast carcinoma than that of ultrasound and mammography. MRI demonstrates its virtues in the research of occult cancers, where mammography and ultrasound can neither detect nor assess the cancer extension; DCE MR imaging has very high sensitivity for breast cancer diagnosis but its specificity is rather unsatisfactory. Because of the high false positive rate at conventional mammography and the noninvasive nature of MR procedures, it is very important to search for MR diagnostic protocols for breast cancer that have high specificity but are also clinically practical. The results of the studies showed that the combined MR imaging– MR spectroscopy protocol, which consisted of DCE MR imaging, 1H MR spectroscopy, and perfusion MR imaging, had 100% specificity in the detection of breast malignancy. It therefore possesses the potential to be used as a standard screening tool following positive mammographic diagnosis, to avoid the performance of unnecessary biopsy procedures. The MR techniques used in this protocol are now available on some commercial MR imagers and can be easily implemented with standardized data acquisition parameters. This grants an advantage to larger clinical trials of this method, as the MR data can be rigorously compared among different clinical sites. The total imaging time, including all three sequences, is usually less than 40 minutes, and the procedures are tolerable for patients. The total contrast agent dose used is no more than 0.2 mmol per kilogram of body weight, which is a dose well below the limit approved by the U.S.Food and Drug Administration. Therefore, it is believed that this combined MR imaging–MR spectroscopy protocol is practical for breast cancer diagnosis in clinical settings.