Breast disease: Dynamic spiral MR imaging

Purpose: To compare various subjective, empiric, and pharmacokinetic methods for interpreting findings at dynamic magnetic resonance (MR) imaging of the breast. Materials and methods: Dynamic spiral breast MR imaging was performed in 52 women suspected of having or with known breast disease. Gadolinium-enhanced images were obtained at 12 locations through the whole breast every 7.8 seconds for 8.5 minutes after bolus injection of contrast material. Time-signal intensity curves from regions of interest corresponding to 57 pathologically proved lesions were analyzed by means of a two-compartment pharmacokinetic model, and the diagnostic performance of various parameters was analyzed. Results: Findings included invasive carcinoma in 17 patients, isolated ductal carcinoma in situ (DCIS) in six, and benign lesions in 34. Although some overlap between carcinomas and benign diagnoses was noted for all parameters, receiver operating characteristic analysis indicated that the exchange rate constant had the greatest overall ability to discriminate benign and malignant disease. The elimination rate constant and washout were the most specific parameters. The exchange rate constant wash-in, and extrapolation point were the most sensitive parameters. DCIS was not consistently distinguished from benign disease with any method. Conclusion: Dynamic spiral breast MR imaging proved an excellent method with which to collect contrast enhancement data rapidly enough that accurate comparisons can be made between many analytic methods.