1
|
Li CX, Zhang X. Evaluation of prolonged administration of isoflurane on cerebral blood flow and default mode network in macaque monkeys anesthetized with different maintenance doses. Neurosci Lett 2018; 662:402-408. [PMID: 29055725 PMCID: PMC5722273 DOI: 10.1016/j.neulet.2017.10.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 09/27/2017] [Accepted: 10/17/2017] [Indexed: 12/30/2022]
Abstract
OBJECT Isoflurane is a commonly used volatile anesthetic agent in clinical anesthesia and biomedical research. Prior study suggested the cerebral blood flow (CBF) and default mode network (DMN) could be changed after prolonged administration of isoflurane. The normal maintenance doses of isoflurane may vary from light (∼0.75%) to deep (∼1.5 or 2%) anesthesia. However, it is not clear how the duration effects are affected by the altered doses. The present study is aimed to examine if the duration effects are affected when isoflurane concentration is altered within normal maintenance doses. MATERIALS AND METHODS Adult rhesus monkeys (n=5, 8-12 years old, 8-10kg) were anesthetized and maintained at isoflurane levels 0.89±0.03%, 1.05±0.12%, or 1.19±0.08%. CBF and DMN of monkeys were examined using arterial spin-labeling perfusion and resting state functional MRI techniques. RESULTS the functional connectivity (FC) in the dominant DMN (posterior cingulate cortex (PCC) to anterior cingulated cortex (ACC) or media prefrontal cortex (MPFC)) decreased substantially and similarly during 4-h administration of isoflurane at any given maintenance dosage. CBF changes varied with isoflurane dosage. At the low dose (∼0.89%), CBF decreased in most brain regions. In contrast, no obvious changes was seen in those regions (except for the subcortex) when higher doses of isoflurane were applied. CONCLUSION FC in DMN was reduced substantially during prolonged administration of isoflurane. The FC reduction was not varying significantly with maintenance doses of isoflurane but the duration effect on CBF was dose-dependent. Such duration effects of isoflurane administration on DMN and CBF should be considered in the interpretation of the outcome in related neuroimaging studies of anesthetized subjects.
Collapse
Affiliation(s)
- Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, United States
| | - Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, United States; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, United States.
| |
Collapse
|
2
|
Zhang X, Li CX. Arterial spin labeling perfusion magnetic resonance imaging of non-human primates. Quant Imaging Med Surg 2016; 6:573-581. [PMID: 27942478 DOI: 10.21037/qims.2016.10.05] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Non-human primates (NHPs) resemble most aspects of humans in brain physiology and anatomy and are excellent animal models for translational research in neuroscience, biomedical research and pharmaceutical development. Cerebral blood flow (CBF) offers essential physiological information of the brain to examine the abnormal functionality in NHP models with cerebral vascular diseases and neurological disorders or dementia. Arterial spin labeling (ASL) perfusion MRI techniques allow for high temporal and spatial CBF measurement and are intensively used in studies of animals and humans. In this article, current high-resolution ASL perfusion MRI techniques for quantitative evaluation of brain physiology and function in NHPs are described and their applications and limitation are discussed as well.
Collapse
Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA;; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
| |
Collapse
|
3
|
Is the Susceptibility Vessel Sign on 3-Tesla Magnetic Resonance T2*-Weighted Imaging a Useful Tool to Predict Recanalization in Intravenous Tissue Plasminogen Activator? Clin Neuroradiol 2014; 26:317-23. [PMID: 25516146 DOI: 10.1007/s00062-014-0363-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
The aim of this study was to investigate the independent factors associated with the absence of recanalization approximately 24 h after intravenous administration of tissue-type plasminogen activator (IV TPA). The previous studies have been conducted using 1.5-Tesla (T) magnetic resonance imaging (MRI). We studied whether the characteristics of 3-T MRI findings were useful to predict outcome and recanalization after IV tPA. Patients with internal carotid artery (ICA) or middle cerebral artery (MCA) (horizontal portion, M1; Sylvian portion, M2) occlusion and treated by IV tPA were enrolled. We studied whether the presence of susceptibility vessel sign (SVS) at M1 and low clot burden score on T2*-weighted imaging (T2*-CBS) on 3-T MRI were associated with the absence of recanalization. A total of 49 patients were enrolled (27 men; mean age, 73.9 years). MR angiography obtained approximately 24 h after IV tPA revealed recanalization in 21 (42.9 %) patients. Independent factors associated with the absence of recanalization included ICA or proximal M1 occlusion (odds ratio, 69.6; 95 % confidence interval, 5.05-958.8, p = 0.002). In this study, an independent factor associated with the absence of recanalization may be proximal occlusion of the cerebral arteries rather than SVS in the MCA or low T2*-CBS on 3-T MRI.
Collapse
|
4
|
Krongold M, Almekhlafi MA, Demchuk AM, Coutts SB, Frayne R, Eilaghi A. Final infarct volume estimation on 1-week follow-up MR imaging is feasible and is dependent on recanalization status. NEUROIMAGE-CLINICAL 2014; 7:1-6. [PMID: 25429356 PMCID: PMC4238048 DOI: 10.1016/j.nicl.2014.10.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/10/2014] [Accepted: 10/29/2014] [Indexed: 11/01/2022]
Abstract
PURPOSE We aim to characterize infarct volume evolution within the first month post-ischemic stroke and to determine the effect of recanalization status on early infarct volume estimation. METHODS Ischemic stroke patients recruited for the MONITOR and VISION studies were retrospectively screened and patients who had infarcts on diffusion-weighted imaging (DWI) at baseline and had at least two follow-up MR scans (n = 56) were included. Pre-defined target imaging time points, obtained on a 3-T MR scanner, were 12 hours (h), 24 h, 7 days, and ≥30 days post-stroke. Infarct tissue was manually traced blinded to the images at the other time points. Infarct expansion index was calculated by dividing infarct volume at each follow-up time point by the baseline DWI infarct volume. Recanalization was assessed within 24 h post-stroke. Correlation and statistical comparison analysis were done using the Spearman, Mann-Whitney, and Kruskal-Wallis tests. RESULTS Follow-up infarct volumes were positively correlated with the baseline infarct volume (ρ > 0.81; p < 0.001) where the strongest correlation existed between baseline and 7-day post-stroke infarct volumes (ρ = 0.92; p < 0.001). The strongest correlation among the follow-up imaging was found between infarct volumes 7-day post-stroke and ≥30-day time points (ρ = 0.93; p < 0.001). Linear regression showed a close-to unity slope between 7-day and final infarct volumes (slope = 1.043; p < 0.001). Infarct expansion was higher in the non-recanalized group than the recanalized group at the 7-day (p = 0.001) and ≥30-day (p = 0.038) time points. CONCLUSIONS Final infarct volume can be approximated as early as 7 days post-stroke. Final infarct volume approximation is significantly associated with recanalization status.
Collapse
Affiliation(s)
- Mark Krongold
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
| | - Mohammed A Almekhlafi
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; King Abdulaziz University, Jeddah, Saudi Arabia
| | - Andrew M Demchuk
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; Calgary Stroke Program, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Shelagh B Coutts
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; Calgary Stroke Program, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Richard Frayne
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
| | - Armin Eilaghi
- Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada ; Seaman Family Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Alberta, Canada ; Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
5
|
Murai Y, Mizunari T, Takagi R, Amano Y, Mizumura S, Komaba Y, Okubo S, Kobayashi S, Teramoto A. Analysis of ischemic cerebral lesions using 3.0-T diffusion-weighted imaging and magnetic resonance angiography after revascularization surgery for ischemic disease. Clin Neurol Neurosurg 2013. [DOI: 10.1016/j.clineuro.2012.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
6
|
Deconvolution with simple extrapolation for improved cerebral blood flow measurement in dynamic susceptibility contrast magnetic resonance imaging during acute ischemic stroke. Magn Reson Imaging 2011; 29:620-9. [PMID: 21546188 DOI: 10.1016/j.mri.2011.02.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Revised: 02/02/2011] [Accepted: 02/20/2011] [Indexed: 11/21/2022]
Abstract
Magnetic resonance (MR) perfusion imaging is a clinical technique for measuring brain blood flow parameters during stroke and other ischemic events. Ischemia in brain tissue can be difficult to accurately measure or visualize when using MR-derived cerebral blood flow (CBF) maps. The deconvolution techniques used to estimate flow can introduce a mean transit time-dependent bias following application of noise stabilization techniques. The underestimation of the CBF values, greatest in normal tissues, causes a decrease in the image contrast observed in CBF maps between normally perfused and ischemic tissues; resulting in ischemic areas becoming less conspicuous. Through application of the proposed simple extrapolation technique, CBF biases are reduced when missing high-frequency signal components in the MR data removed during deconvolution noise stabilization are restored. The extrapolation approach was compared with other methods and showed a statistically significant increase in image contrast in CBF maps between normal and ischemic tissues for white matter (P<.05) and performed better than most other methods for gray matter. Receiver operator characteristic curve analysis demonstrated that extrapolated CBF maps better-detected penumbral regions. Extrapolated CBF maps provided more accurate CBF estimates in simulations, suggesting that the approach may provide a better prediction of outcome in the absence of treatment.
Collapse
|
7
|
DeVetten G, Coutts SB, Hill MD, Goyal M, Eesa M, O'Brien B, Demchuk AM, Kirton A. Acute corticospinal tract Wallerian degeneration is associated with stroke outcome. Stroke 2010; 41:751-6. [PMID: 20203322 DOI: 10.1161/strokeaha.109.573287] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND PURPOSE In children with stroke, poor motor outcome is associated with early Wallerian degeneration of the corticospinal tract that is seen on diffusion-weighted MRI. In this study we test the hypothesis that early diffusion changes also occur in the corticospinal tract (CST) of adults after stroke and that these lesions are associated with poor outcome. METHODS In this retrospective study, we assessed images from a serial MRI study of adults with acute middle cerebral/internal carotid artery stroke. MRI-negative TIA patients served as controls. Custom software measured signal along the CST on different sequences, including the apparent diffusion coefficient (ADC). Visual detection of abnormal signal by blinded neuroradiologists was also evaluated. We then determined associations between CST signal changes and 3-month motor outcome (NIHSS score). RESULTS Thirty-eight patients (20 stroke/18 control) were included. ADC measures were much more accurate than other MRI sequences for detection of degeneration in the CST. The ADC decreased in a time-dependent fashion in the CST of patients with poor motor outcome but not in those with good outcome. Changes in ADC were maximal at 7 days. Neuroradiologists could visually detect these changes with accuracy comparable to the software method. CONCLUSION CST ADC decreases after acute stroke in patients with poor motor outcome and may represent early Wallerian degeneration. Recognition of this imaging marker may improve early outcome prediction and patient selection for rehabilitation and neuroprotection trials.
Collapse
Affiliation(s)
- Giselle DeVetten
- Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Alberta, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Bristow MS, Poulin BW, Simon JE, Hill MD, Kosior JC, Coutts SB, Frayne R, Mitchell JR, Demchuk AM. Identifying lesion growth with MR imaging in acute ischemic stroke. J Magn Reson Imaging 2008; 28:837-46. [DOI: 10.1002/jmri.21507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|