Early evolution of deficits in acute ischemic stroke: Mean transit time, relative blood volume, and relative blood flow

2002 ◽  
Vol 11 (2) ◽  
pp. 66-71 ◽  
Author(s):  
Thanh G. Phan ◽  
John Huston ◽  
Norbert G. Campeau ◽  
Robert D. Brown ◽  
Jimmy R. Fulgham ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Volume ◽  
Transit Time ◽  
Mean Transit Time ◽  
Early Evolution ◽  
Relative Blood Volume

scholarly journals The Effects of Changes in PaCO2Cerebral Blood Volume, Blood Flow, and Vascular Mean Transit Time

Stroke ◽  
1974 ◽  
Vol 5 (5) ◽  
pp. 630-639 ◽  
Author(s):  
ROBERT L. GRUBB ◽  
MARCUS E. RAICHLE ◽  
JOHN O. EICHLING ◽  
MICHEL M. TER-POGOSSIAN
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Transit Time ◽  
Mean Transit Time ◽  
Volume Blood ◽  
Volume Blood Flow

Effects of graded hypotension on cerebral blood flow, blood volume, and mean transit time in dogs

1992 ◽  
Vol 262 (6) ◽  
pp. H1908-H1914 ◽  
Author(s):  
M. Ferrari ◽  
D. A. Wilson ◽  
D. F. Hanley ◽  
R. J. Traystman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Perfusion Pressure ◽  
Blood Volume ◽  
Transit Time ◽  
Cerebral Perfusion ◽  
Pressure Range ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Mean Transit Time

This study tested the hypothesis that cerebral blood flow (CBF) is maintained by vasodilation, which manifests itself as a progressive increase in mean transit time (MTT) and cerebral blood volume (CBV) when cerebral perfusion pressure is reduced. Cerebral perfusion pressure was decreased in 10 pentobarbital-anesthetized dogs by controlled hemorrhage. Microsphere-determined CBF was autoregulated in all tested cerebral regions over the 40- to 130-mmHg cerebral perfusion pressure range but decreased by 50% at approximately 30 mmHg. MTT and CBV progressively and proportionately increased in the right parietal cerebral cortex over the 40- to 130-mmHg cerebral perfusion pressure range. Total hemoglobin content (Hb1), measured in the same area by an optical method, increased in parallel with the increases in CBV computed as the (CBF.MTT) product. At 30 mmHg cerebral perfusion pressure, CBV and Hb were still increased and MTT was disproportionately lengthened (690% of control). We conclude that within the autoregulatory range, CBF constancy is maintained by both increased CBV and MTT. Outside the autoregulatory range, substantial prolongation of the MTT occurs. When CBV is maximal, further reductions in cerebral perfusion pressure produce disproportionate increases in MTT that signal the loss of cerebral vascular dilatory hemodynamic reserve.

scholarly journals Reliable Estimation of Capillary Transit Time Distributions Using DSC-MRI

2014 ◽  
Vol 34 (9) ◽  
pp. 1511-1521 ◽  
Author(s):  
Kim Mouridsen ◽  
Mikkel Bo Hansen ◽  
Leif Østergaard ◽  
Sune Nørhøj Jespersen
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Transit Time ◽  
Neuronal Response ◽  
Mean Transit Time ◽  
Oxygen Extraction Fraction ◽  
Dynamic Susceptibility ◽  
Arterial Blood ◽  
Dsc Mri ◽  
Wide Range

The regional availability of oxygen in brain tissue is traditionally inferred from the magnitude of cerebral blood flow ( CBF) and the concentration of oxygen in arterial blood. Measurements of CBF are therefore widely used in the localization of neuronal response to stimulation and in the evaluation of patients suspected of acute ischemic stroke or flow-limiting carotid stenosis. It was recently demonstrated that capillary transit time heterogeneity ( CTH) limits maximum oxygen extraction fraction ( OEFmax) that can be achieved for a given CBF. Here we present a statistical approach for determining CTH, mean transit time ( MTT), and CBF using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). Using numerical simulations, we demonstrate that CTH, MTT, and OEFmax can be estimated with low bias and variance across a wide range of microvascular flow patterns, even at modest signal-to-noise ratios. Mean transit time estimated by singular value decomposition (SVD) deconvolution, however, is confounded by CTH. The proposed technique readily identifies malperfused tissue in acute stroke patients and appears to highlight information not detected by the standard SVD technique. We speculate that this technique permits the non-invasive detection of tissue with impaired oxygen delivery in neurologic disorders such as acute ischemic stroke and Alzheimer's disease during routine diagnostic imaging.

scholarly journals A Novel Method to Derive Separate Gray and White Matter Cerebral Blood Flow Measures from MR Imaging of Acute Ischemic Stroke Patients

2005 ◽  
Vol 25 (9) ◽  
pp. 1236-1243 ◽  
Author(s):  
Jessica E Simon ◽  
Michael S Bristow ◽  
Hong Lu ◽  
M Louis Lauzon ◽  
Robert A Brown ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
White Matter ◽  
Acute Ischemic Stroke ◽  
Spin Echo ◽  
Statistical Significance ◽  
Mean Transit Time ◽  
Inversion Recovery ◽  
Normal Brain

Perfusion-weighted imaging (PWI) measures can predict tissue outcome in acute ischemic stroke. Accuracy might be improved if differential tissue susceptibility to ischemia is considered. We present a novel voxel-by-voxel analysis to characterize cerebral blood flow (CBF) separately in gray (GM) and white matter (WM). Ten patients were scanned with inversion-recovery spin-echo EPI (IRSEPI), diffusion-weighted imaging (DWI), PWI<6 h from onset and fluid attenuated inversion-recovery (FLAIR) at 30 days. Image processing included coregistration to PWI, automatic segmentation of IRSEPI into GM, WM and CSF and semiautomatic segmentation of DWI/FLAIR to derive the acute and 30-day lesions. Five tissue compartments were defined: (1) ‘Core’ (abnormal acutely and at 30 days), (2) ‘Growth’ (or ‘infarcted penumbra', abnormal only at 30 days), (3) ‘Reversed’ (abnormal acutely but normal at 30 days), (4) ‘MTT-Delayed ‘ (tissue with delayed mean transit time but not part of the acute or 30-day lesion), and (5) ‘Normal’ brain. Cerebral blood flow in GM and WM of each compartment was obtained from quantitative maps. Gray matter and WM mean CBF in the growth region differed by 5.5 mL/100 g min ( P = 0.015). Mean CBF also differed significantly within normal and MTT-Delayed compartments. The difference in the reversed region approached statistical significance. In core, GM and WM CBF did not differ. The results suggest separate ischemic thresholds for GM and WM in stroke penumbra.

scholarly journals Brain hemorrhage after endovascular reperfusion therapy of ischemic stroke: a threshold-finding whole-brain perfusion CT study

2016 ◽  
Vol 37 (1) ◽  
pp. 153-165 ◽  
Author(s):  
Arturo Renú ◽  
Carlos Laredo ◽  
Raúl Tudela ◽  
Xabier Urra ◽  
Antonio Lopez-Rueda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Reperfusion Therapy ◽  
Perfusion Ct ◽  
Regression Analyses ◽  
Relative Cerebral Blood Volume

Endovascular reperfusion therapy is increasingly used for acute ischemic stroke treatment. The occurrence of parenchymal hemorrhage is clinically relevant and increases with reperfusion therapies. Herein we aimed to examine the optimal perfusion CT-derived parameters and the impact of the duration of brain ischemia for the prediction of parenchymal hemorrhage after endovascular therapy. A cohort of 146 consecutive patients with anterior circulation occlusions and treated with endovascular reperfusion therapy was analyzed. Recanalization was assessed at the end of reperfusion treatment, and the rate of parenchymal hemorrhage at follow-up neuroimaging. In regression analyses, cerebral blood volume and cerebral blood flow performed better than Delay Time maps for the prediction of parenchymal hemorrhage. The most informative thresholds (receiver operating curves) for relative cerebral blood volume and relative cerebral blood flow were values lower than 2.5% of normal brain. In binary regression analyses, the volume of regions with reduced relative cerebral blood volume and/or relative cerebral blood flow was significantly associated with an increased risk of parenchymal hemorrhage, as well as delayed vessel recanalization. These results highlight the relevance of the severity and duration of ischemia as drivers of blood-brain barrier disruption in acute ischemic stroke and support the role of perfusion CT for the prediction of parenchymal hemorrhage.

The association between neurological deficit in acute ischemic stroke and mean transit time

2005 ◽  
Vol 48 (2) ◽  
pp. 69-77 ◽  
Author(s):  
Peter D. Schellinger ◽  
Lawrence L. Latour ◽  
Chen-Sen Wu ◽  
Julio A. Chalela ◽  
Steven Warach
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Transit Time ◽  
Neurological Deficit ◽  
Mean Transit Time

scholarly journals Cerebral Blood Flow, Blood Volume, and Mean Transit Time Responses to Propofol and Indomethacin in Peritumor and Contralateral Brain Regions

2010 ◽  
Vol 112 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Mads Rasmussen ◽  
Niels Juul ◽  
Søren M. Christensen ◽  
Kristjana Y. Jónsdóttir ◽  
Carsten Gyldensted ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Tumors ◽  
Blood Volume ◽  
Transit Time ◽  
Gray Matter ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Brain Regions ◽  
Normal Brain

Background The regional cerebral blood flow (CBF) response to propofol and indomethacin may be abnormal in patients with brain tumors. First, the authors tested the hypothesis that during propofol anesthesia alone and combined with indomethacin, changes in CBF, cerebral blood volume (CBV), and plasma mean transit time (MTT) differ in the peritumoral tissue compared with the contralateral normal brain region. Second, the authors tested the hypothesis that CBF and CBV are reduced and MTT is prolonged, in both regions during propofol anesthesia and indomethacin administration compared with propofol alone. Methods The authors studied eight patients subjected to craniotomy under propofol-fentanyl anesthesia for supratentorial brain tumors. Magnetic resonance imaging, including perfusion- and diffusion-weighted and structural sequences, was performed (1) on the day before surgery, (2) before and (3) after administration of indomethacin in the propofol-fentanyl anesthetized patient, and (4) 2 days after surgery. Maps of CBF, CBV, and MTT were calculated. The regions of interest were peritumoral gray matter and opposite contralateral gray matter. Analysis of variance was used to analyze flow data. Results Propofol anesthesia was associated with a median 32% (range, 3-61%) and 47% (range, 17-67%) reduction in CBF in the peritumoral and contralateral regions, respectively.The interaction between intervention with propofol and indomethacin and region of interest was not significant for any flow modalities. Neither intervention nor region was significant for MTT, CBF, and CBV (P &gt; 0.05). Conclusion The CBF, CBV, and MTT responses to propofol and indomethacin are not different in the peritumoral region compared with contralateral brain tissue. Indomethacin did not further influence regional CBF, CBV, and MTT during propofol anesthesia.

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