Test‐retest reproducibility of quantitative CBF measurements using FAIR perfusion MRI and acetazolamide challenge

Abstract

The reproducibility of quantitative cerebral blood flow (CBF) measurements using MRI with arterial spin labeling and acetazolamide challenge was assessed in 12 normal subjects, each undergoing the identical experimental procedure on two separate days. CBF was measured on a 1.5T scanner using a flowsensitive alternating inversion recovery (FAIR) pulse sequence, performed both at baseline and 12 min after intravenous administration of acetazolamide. T 1 was measured in conjunction with the FAIR scan in order to calculate quantitative CBF. The CBF maps were segmented to separate gray matter (GM) from white matter (WM) for region-of-interest (ROI) analyses. Postacetazolamide CBF values (ml/100 g/min, mean ؎ SD) of 87.5 ؎ 12.5 (GM) and 46.1 ؎ 10.8 (WM) represented percent increases of 37.7% ؎ 24.4% (GM) and 40.1% ؎ 24.4% (WM). Day-to-day differences in baseline CBF were ؊1.7 ؎ 6.9 (GM) and -1.4 ؎ 4.7 (WM) or, relative to the mean CBF over both days for each subject, -2.5% ؎ 11.7% (GM) and ؊3.8% ؎ 13.6% (WM) Dayto-day differences in absolute post-ACZ CBF increase were ؊2.5 ؎ 6.8 (GM) and 2.7 ؎ 9.4 (WM) or, relative to the mean CBF increase over both days for each subject, -4.7% ؎ 13.3% (GM) and 9.1%

Age‐related cerebral perfusion changes in the parietal and temporal lobes measured by pulsed arterial spin labeling

“…Based on the coefficient of variation which was 7.9 % in the global GM ROI, we conclude that the reproducibility of our measurements lies well in the range reported for other pulsed (28)(29)(30) and continuous ASL (31)(32)(33)(34) methods. A recent multi center study at 3T including 28 sites (29) using a PASL method termed QUASAR (35,36) reported values for SD w in GM between 3.01 and 8.12 ml/100 g/min, which suggests that the reproducibility of our measurements is quite high.…”

An investigation of statistical power for continuous arterial spin labeling imaging at 1.5 T

“…Yen et al reported variance of PASL CBF at 1.5 T from GM ROI in a single slice (Yen et al, 2002). ROI size across subjects varied from 50 -80 cc, similar in size to our hippocampal and BA 4 ROIs.…”

Arterial Spin-Labeling Evaluation of Cerebrovascular Reactivity to Acetazolamide in Healthy Subjects

“…ASL MR imaging is a safe, rapid method of measuring CBF and is applicable to the assessment of CVR. [7][8][9][10][11][12] In the present study, we evaluated cerebrovascular response to ACZ by 3D pseudocontinuous ASL MR imaging. Repeated ASL imaging after ACZ injection demonstrated a CBF increase in the whole brain visually and quantitatively.…”

“…The mean CVR values reported in normal subjects range from 25-31% with the use of 133 Xe inhalation SPECT, 18,21-23 from 33.5-35% with the use of 15 O-water positron-emission tomography, 24,25 and from 37.7-54.2% with the use of ASL MR imaging. [9][10][11] Although the CVR values obtained with the use of a PLD of either 1525 ms (43.8 -46.4%, depending on the region) or 2525 ms (26.9 -32.5%) in the present study are in the range of the reported values, those obtained with a PLD of 1525 ms as well as those previously reported by use of ASL MR imaging are relatively high; thus, ASL MR imaging probably leads to overestimation of CVR. The method that provides more accurate CVR cannot be concluded because of the lack of a standard reference; however, our results indicate that the influence of the PLD on CVR estimates should be taken into consideration.…”

“…CBF and CVR can be assessed by ASL MR imaging with ACZ. [7][8][9][10][11][12] The ASL technique allows estimation of rest and post-ACZ CBFs, in addition to morphologic assessments by conventional MR imaging, in one imaging session. In the present study, we used 3D pseudocontinuous ASL imaging to evaluate CVR to ACZ in healthy volunteers.…”