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Free keywords:
Arterial input function; Deconvolution; Dynamic susceptibility contrast MRI; perfusion
Abstract:
For longitudinal studies in patients suffering from cerebrovascular
diseases the poor reproducibility of perfusion measurements via
dynamic susceptibility-weighted contrast-enhanced MRI (DSC-
MRI) is a relevant concern. We evaluate a novel algorithm capable
of overcoming limitations in DSC-MRI caused by partial volume
and saturation issues in the arterial input function (AIF) by a blood
flow stimulation-study. In 21 subjects, perfusion parameters be-
fore and after administration of blood flow stimulating
L
-arginine
were calculated utilizing a block-circulant singular value decom-
position (cSVD). A total of two different raters and three different
rater conditions were employed to select AIFs: Besides 1) an AIF
selection by an experienced rater, a beginner rater applied a
steady state-oriented strategy, returning; 2) raw; and 3) corrected
AIFs. Highly significant changes in regional cerebral blood flow
(rCBF) by 9.0% (
P
<
0.01) could only be found when the AIF
correction was performed. To further test for improved reproduc-
ibility, in a subgroup of seven subjects the baseline measurement
was repeated 6 weeks after the first examination. In this group as
well, using the correction algorithm decreased the SD of the dif-
ference between the two baseline measurements by 42%.
