Abstract
PURPOSE
To determine whether whole-brain acetazolamide-induced changes in regional cerebral blood volume (rCBV) can be assessed on a conventional gradient 1.5-T MR system using 3-D dynamic susceptibility contrast-enhanced MR imaging.
METHODS
A 3-D frequency-shifted (FS) burst technique was used to assess the intravascular first pass of contrast agent. Changes in rCBV were calculated in 40 volunteers before and after acetazolamide (n = 30) or saline (n = 10) injection using customized analysis software on an independent workstation. A single-section gradient-echo technique with better spatial resolution was used in one additional volunteer to examine the effect of partial volume averaging on calculation of absolute rCBV.
RESULTS
A statistically significant increase in rCBV (gray matter = 23%, white master = 32.5%) was noted after acetazolamide compared with saline. Baseline fractional CBVs were 22% +/- 3% for gray matter and 12% +/- 2% for white matter. Partial volume averaging was probably responsible for a systematic but linear overestimation of absolute rCBV.
CONCLUSION
Acetazolamide-induced changes in rCBV can be assessed using 3-D dynamic susceptibility contrast-enhanced MR imaging with FS-burst on a conventional gradient 1.5-T MR system. Values obtained with this technique overestimate absolute rCBV but are systematically biased and can be used for intersubject and intrasubject ratio comparisons.
Full Text
The Full Text of this article is available as a PDF (649.2 KB).