PT  - JOURNAL ARTICLE
AU  - Horn, Peter
AU  - Vajkoczy, Peter
AU  - Thomé, Claudius
AU  - Muench, Elke
AU  - Schilling, Lothar
AU  - Schmiedek, Peter
TI  - Xenon-Induced Flow Activation in Patients with Cerebral Insult Who Undergo Xenon-Enhanced CT Blood Flow Studies
DP  - 2001 Sep 01
TA  - American Journal of Neuroradiology
PG  - 1543--1549
VI  - 22
IP  - 8
4099  - http://www.ajnr.org/content/22/8/1543.short
4100  - http://www.ajnr.org/content/22/8/1543.full
SO  - Am. J. Neuroradiol.2001 Sep 01; 22
AB  - BACKGROUND AND PURPOSE: Stable xenon–enhanced CT (sXe/CT) has gained wide acceptance in the assessment of regional cerebral blood flow (rCBF) in patients with intracranial abnormalities. The aim of this study was to test whether the contrast medium (ie, sXe) itself directly induces relevant changes in rCBF, thereby distorting any valid determination of cerebral perfusion by using sXe/CT.METHODS: To characterize the degree and temporal dynamics of sXe-induced flow activation, a thermal diffusion (TD)-based microprobe was placed subcortically into the frontal lobe on either hemisphere to assess rCBF (TD-rCBF) continuously in 23 patients (mean age, 55 ± 18 years) with severe intracranial insult who were undergoing sXe/CT.RESULTS: In 35, the sXe/CT studies TD-rCBF rose from 25 ± 17 mL/100 g per minute (range, 5–42 mL/100 g per minute) before sXe administration to 28 ± 21 mL/100 g per minute (range, 6–46 mL/100 g per minute) after arterial sXe saturation was reached. Analysis of the flow activation curve showed a logarithmic shape with an increase in TD-rCBF between 3% and 7% within the first 76 seconds of sXe wash-in (12% after 190 seconds) and showed no further augmentation until the end of the blood flow study.CONCLUSION: The observed sXe-induced rCBF activation, which showed significant inter- and intraindividual variability, might lead to overestimation of rCBF in patients with severe intracranial insult. The obtained flow activation curve provides essential information that may allow subsequent refinement of the methodology, aiming to further minimize the influence of sXe-induced rCBF activation on rCBF calculations when using sXe/CT technology.