Neurology Commons^™

Characterizing Tissue Fate After Transient Cerebral Ischemia Of Varying Duration Using Quantitative Diffusion And Perfusion Imaging, Juergen Bardutzky, Qiang Shen, Nils Henninger, Stefan Schwab, Timothy Duong, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: The purpose of this study was to investigate the effects of reperfusion on ischemic lesion evolution and pixel-by-pixel apparent diffusion coefficient-cerebral blood flow (ADC-CBF) dynamics of core and mismatch tissues after 35, 60, and 95 minutes of transient focal ischemia in rats (n=28). METHODS: Serial diffusion-, perfusion-, and T2-weighted imaging were performed up to 24 hours. The evolution of the magnetic resonance image-derived lesion volume was investigated and ADC-CBF scatterplots were performed to prospectively characterize the ADC and CBF dynamics of core and mismatch tissues with different fates. For comparison, similar analysis was performed on a historical …

Comparison Of Ischemic Lesion Evolution In Embolic Versus Mechanical Middle Cerebral Artery Occlusion In Sprague Dawley Rats Using Diffusion And Perfusion Imaging, Nils Henninger, Kenneth Sicard, Karl Schmidt, Juergen Bardutzky, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Differences among models in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental stroke research. Using diffusion and perfusion imaging, we compared the spatiotemporal evolution of ischemia in Sprague Dawley rats after permanent suture MCAO (sMCAO; n=8) and embolic MCAO (eMCAO; n=8).

METHODS: Serial measurements of quantitative cerebral blood flow (CBF) and the apparent diffusion coefficient (ADC) were performed up to 180 minutes after MCAO. ADC and CBF values within 5 different brain regions were analyzed. ADC and CBF lesion volumes were calculated by using previously …

Ischemic Lesion Volume Determination On Diffusion Weighted Images Vs. Apparent Diffusion Coefficient Maps, Bernt Bratane, Birgül Bastan, Marc Fisher, James Bouley, Nils Henninger

Nils Henninger

Though diffusion weighted imaging (DWI) is frequently used for identifying the ischemic lesion in focal cerebral ischemia, the understanding of spatiotemporal evolution patterns observed with different analysis methods remains imprecise. DWI and calculated apparent diffusion coefficient (ADC) maps were serially obtained in rat stroke models (MCAO): permanent, 90 min, and 180 min temporary MCAO. Lesion volumes were analyzed in a blinded and randomized manner by 2 investigators using (i) a previously validated ADC threshold, (ii) visual determination of hypointense regions on ADC maps, and (iii) visual determination of hyperintense regions on DWI. Lesion volumes were correlated with 24 hour 2,3,5-triphenyltetrazoliumchloride …

Differences In Ischemic Lesion Evolution In Different Rat Strains Using Diffusion And Perfusion Imaging, Juergen Bardutzky, Qiang Shen, Nils Henninger, James Bouley, Timothy Duong, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Interstrain differences in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental stroke research. We investigated, in 2 commonly used rat strains (Sprague-Dawley [SD] and Wistar-Kyoto [WK]), the spatiotemporal evolution of ischemia after permanent suture MCAO using diffusion and perfusion imaging.

METHODS: Serial measurements of quantitative cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) were performed up to 210 min after MCAO. Lesion volumes were calculated by using previously established viability thresholds and correlated with infarct volume defined by 2,3,5-triphenyltetrazolium chloride staining 24 hours after …

Long-Term Changes Of Functional Mri-Based Brain Function, Behavioral Status, And Histopathology After Transient Focal Cerebral Ischemia In Rats, Kenneth Sicard, Nils Henninger, Marc Fisher, Timothy Duong, Craig Ferris

Nils Henninger

BACKGROUND AND PURPOSE: The relation between recovery of brain function and neurological status after clinical and experimental cerebral ischemia is incompletely characterized. We assessed the evolution of ischemic injury, behavioral status, and brain activity at acute to chronic periods after transient middle cerebral artery occlusion (tMCAO) in rats. METHODS: Male Sprague-Dawley rats were subjected to 20-minute tMCAO (n=10) or sham operation (n=10). Sensorimotor behavioral testing and multimodal (diffusion, perfusion, T2, and functional) MRI, as well as postmortem hematoxylin-eosin staining, were performed before and up to 21 days after tMCAO. MRI and histological parameters were evaluated in 5 regions of interest …