Quantitative gadopentetate-enhanced MRI of breast tumors: Testing of different analytic methods

This study assessed several proposed imaging strategies and analytic method s based on gadopentetate-enhanced MRI to differentiate benign from malignan t breast tumors in a blinded experimental animal study. Steady-state dynami c MRI and first-pass imaging, performed with either T-1- or T-2*- weighted sequences, were compared. Semiquantitative and quantitative analysis method s, based on empirical measures of the data or physiological models, were su bsequently applied to the imaging datasets. Comparative measures provided p athologic distinction of benign from malignant tumors, tumor grading, and h istologic determination of microvascular density. Of the eight tested metho ds, only one, an estimate of first:pass perfusion using T-2*-weighted imagi ng, showed an almost significant (P = 0.05) difference between benign and m alignant tumors and correlated almost significantly (r = .3, P = 0.06) with the tumor grade. Ail other tests, performed either with steady-state imagi ng or with T-1-weighted first-pass imaging, failed to differentiate benign from malignant tumors. In addition, they yielded poor correlations with tum or grade and microvascular density. (C) 2000 Wiley-Liss, Inc.