We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
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-[<sup>14</sup>C]DTPA and marginally overestimates the blood-to-brain influx rate constant determined by Patlak plots
- Authors
Nagaraja, Tavarekere N.; Karki, Kishor; Ewing, James R.; Divine, George W.; Fenstermacher, Joseph D.; Patlak, Clifford S.; Knight, Robert A.
- Abstract
The hypothesis that the arterial input function (AIF) of gadolinium-diethylenetriaminepentaacetic acid injected by intravenous bolus and measured by the change in the T1-relaxation rate (Δ R1; R1 = 1/ T1) of superior sagittal sinus blood (AIF-I) approximates the AIF of 14C-labeled gadolinium-diethylenetriaminepentaacetic acid measured in arterial blood (reference AIF) was tested in a rat stroke model ( n = 13). Contrary to the hypothesis, the initial part of the Δ R1-time curve was underestimated, and the area under the normalized curve for AIF-I was about 15% lower than that for the reference AIF. Hypothetical AIFs for gadolinium-diethylenetriaminepentaacetic acid were derived from the reference AIF values and averaged to obtain a cohort-averaged AIF. Influx rate constants (Ki) and proton distribution volumes at zero time (Vp + Vo) were estimated with Patlak plots of AIF-I, hypothetical AIFs, and cohort-averaged AIFs and tissue Δ R1 data. For the regions of interest, the Kis estimated with AIF-I were slightly but not significantly higher than those obtained with hypothetical AIFs and cohort-averaged AIF. In contrast, Vp + Vo was significantly higher when calculated with AIF-I. Similar estimates of Ki and Vp + Vo were obtained with hypothetical AIFs and cohort-averaged AIF. In summary, AIF-I underestimated the reference AIF; this shortcoming had little effect on the Ki calculated by Patlak plot but produced a significant overestimation of Vp + Vo. Magn Reson Med 63:1502-1509, 2010. © 2010 Wiley-Liss, Inc.
- Publication
Magnetic Resonance in Medicine, 2010, Vol 63, Issue 6, p1502
- ISSN
0740-3194
- Publication type
Article
- DOI
10.1002/mrm.22339