The MRI-measured arterial input function resulting from a bolus injection of Gd-DTPA in a rat model of stroke slightly underestimates that of Gd-[14C]DTPA and marginally overestimates the blood-to-brain influx rate constant determined by Patlak plots

摘要: The hypothesis that the arterial input function (AIF) of gadolinium-diethylenetriaminepentaacetic acid injected by intravenous bolus and measured change in T1-relaxation rate (ΔR1; R1 = 1/T1) superior sagittal sinus blood (AIF-I) approximates AIF 14C-labeled (reference AIF) was tested a rat stroke model (n 13). Contrary to hypothesis, initial part ΔR1-time curve underestimated, area under normalized for AIF-I about 15% lower than reference AIF. Hypothetical AIFs were derived from values averaged obtain cohort-averaged Influx constants (Ki) proton distribution volumes at zero time (Vp + Vo) estimated with Patlak plots AIF-I, hypothetical AIFs, tissue ΔR1 data. For regions interest, Kis slightly but not significantly higher those obtained In contrast, Vp Vo when calculated AIF-I. Similar estimates Ki summary, underestimated AIF; this shortcoming had little effect on plot produced significant overestimation Vo. Magn Reson Med 63:1502–1509, 2010. © 2010 Wiley-Liss, Inc.