Spin-echo echo-planar perfusion MR imaging in the differential diagnosis of solitary enhancing brain lesions: distinguishing solitary metastases from primary glioma

Unlike the more widely reported gradient-echo echo-planar perfusion-weighted imaging (EPI-PWI) technique, spin-echo (SE) EPI relative cerebral blood volume maps select for blood volume in microvessels <8 microm in diameter. This first report of SE-EPI PWI for distinguishing brain metastasis from high-grade glioma demonstrated 88% sensitivity and 72% specificity in 83 patients. We discuss differences in microvessel architecture between high-grade glioma and brain metastasis that may explain the surprising success of SE-EPI in this application and may deserve further investigation.