Ludger Feyen, Abstract Co-Author: Nothing to Disclose

Jens Minnerup, Abstract Co-Author: Nothing to Disclose

Harald Seifarth MD, Abstract Co-Author: Nothing to Disclose

Thomas Niederstadt MD, Abstract Co-Author: Nothing to Disclose

Walter Leonhard Heindel MD, Abstract Co-Author: Nothing to Disclose

Andre Kemmling MD, Presenter: Nothing to Disclose

Significant variability in regional brain perfusion has been demonstrated using PET and SPECT but not in dynamic CT perfusion used for imaging of ischemic stroke. The purpose of this study was to present a comprehensive database of standardized human regional blood flow parameters in healthy elderly using whole brain dynamic perfusion CT.

CT-perfusion maps from brains without evidence for ischemia were consecutively acquired during a 24 months period: 930 patients admitted for acute stroke were evaluated by whole brain CT-perfusion imaging. 107 cases without any perfusion abnormality, infarction or symptoms on follow up or vascular abnormality were included. CT perfusion maps (cerebral blood- flow [CBF], -volume [CBV], time to peak [TTP]) were calculated and linearly co-registered to standard MNI-152 space (FLIRT5.5). A weighted average perfusion value in a priori brain regions defined by the anatomical probability distribution in standardized brain atlas (Harvard Oxford cortical/subcortical atlas) was calculated for each map. Perfusion differences of brain regions were tested by paired t-test (p<0.05) with Bonferroni correction.

Regional perfusion parameters in a total of 68 defined regions were examined (CBV, CBF and TTP) derived from 107 healthy brains. Empirical normal values for perfusion parameters where significantly different for cortex, subcortical grey matter and white matter. The highest cortical grey matter perfusion values were measured in the calcarine gyrus, Heschl’s gyrus and opercular cortex, the lowest in the temporal and frontal cortex. The highest subcortical grey matter perfusion values were found in the Hippocampus, Thalamus and Putamen.

Significantly different CTP derived regional blood flow parameters in cortical and subcortical grey- and white matter were demonstrated in a large series. Our findings are in accord with regional blood flow parameters measured by PET and SPECT. There is evidence that regional rather than whole brain blood flow thresholds may be a more precise measure of predicting the likelihood of infarction. The presented standardized CT-perfusion maps can be used for automated stroke evaluation to improve assessment of regional tissue at risk.

A standardized regional CT perfusion map is presented to address the need for harmonization of quantitative methods to assess brain perfusion in acute stroke imaging.

Feyen, L, Minnerup, J, Seifarth, H, Niederstadt, T, Heindel, W, Kemmling, A, Standardization of Dynamic Whole-Brain Perfusion CT: A Comprehensive Database of Regional Perfusion Parameters.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9012353.html