DUAL DYNAMIC CONTRAST-ENHANCED MR-IMAGING

A method was devised for obtaining dynamic contrast-enhanced T1-weight ed and relaxation rate (Delta R2) images simultaneously to evaluate r egional hemodynamics of the brain tumors. On a 1.5-T MR system, dual d ynamic contrast-enhanced images were obtained using a gradient echo (d ual echo fast held echo) pulse sequence with the keyhole technique to improve temporal and spatial resolution during a rapid bolus injection of gadopentetate dimeglumine. The dynamic T1 contrast images were obt ained from the first echo; moreover. integral Delta R2dt values were calculated from the first and the second echo images, The dynamic T1 c ontrast images provided information about characteristic enhancement p attern (vascularization and disruption of blood-brain barrier), and th e integral Delta R2dt values provided a map of regional blood pool in tumor site, peritumoral edema, and other surrounding regions of the b rain. The ability to obtain dynamic contrast-enhanced T1 contrast and Delta R2 imaging at the same time allows optimization of the advantag es of each and thereby more information about the microvascular circul ation of the brain lesions.