Title
Pixel-by-pixel spatiotemporal progression of focal ischemia derived using quantitative perfusion and diffusion imaging
UMMS Affiliation
Department of Neurology; Department of Radiology; Graduate School of Biomedical Sciences
Publication Date
2003-12
Document Type
Article
Subjects
Acute Disease; Animals; Brain Ischemia; *Cerebrovascular Circulation; Diffusion; Diffusion Magnetic Resonance Imaging; Image Processing, Computer-Assisted; Male; Perfusion; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Stroke
Disciplines
Nervous System Diseases | Neurology | Radiology
Abstract
Pixel-by-pixel spatiotemporal progression of focal ischemia (permanent occlusion) in rats was investigated using quantitative perfusion and diffusion magnetic resonance imaging every 30 minutes for 3 hours. The normal left-hemisphere apparent diffusion coefficient (ADC) was 0.76 +/- 0.03 x 10(-3) mm(2)/s and CBF was 0.7 +/- 0.3 mL x g(-1) x min(-1) (mean +/- SD, n=5). The ADC and CBF viability thresholds yielding the lesion volumes (LV) at 3 hours that best approximated the 2,3,5-triphenyltetrazolium chloride (TTC) infarct volumes (200 +/- 30 mm(3)) at 24 hours were 0.53 +/- 0.02 x 10(-3) mm(2)/s (30% +/- 2% reduction) and 0.30 +/- 0.09 mL x g(-1) x min(-1) (57% +/- 11% reduction), respectively. Temporal evolution of the ADC- and CBF-defined LV showed a significant "perfusion-diffusion mismatch" up to 2 hours (P < 0.05, n = 11), a potential therapeutic window. Based on the viability thresholds, three pixel clusters were identified on the CBF-ADC scatterplots: (1) a "normal" cluster with normal CBF and ADC, (2) an "ischemic core" cluster with markedly reduced CBF and ADC, and (3) a "mismatch" cluster with reduced CBF but slightly reduced ADC. These clusters were color-coded and mapped onto the image and CBF-ADC spaces. Lesions grew peripheral and medial to the initial ADC abnormality. In contrast to the CBF distribution, the ADC distribution in the ischemic hemisphere was bimodal; the relatively time-invariant bimodal-ADC minima were 0.57 +/- 0.02 x 10(-3) mm(2)/s (corresponding CBF 0.35 +/- 0.04 mL x g(-1) x min(-1)), surprisingly similar to the TTC-derived thresholds. Together, these results illustrate an analysis approach to systemically track the pixel-by-pixel spatiotemporal progression of acute ischemic brain injury.
DOI of Published Version
10.1097/01.WCB.0000100064.36077.03
Source
J Cereb Blood Flow Metab. 2003 Dec;23(12):1479-88. Link to article on publisher's site
Journal/Book/Conference Title
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
Related Resources
PubMed ID
14663344
Repository Citation
Shen Q, Meng X, Fisher M, Sotak CH, Duong TQ. (2003). Pixel-by-pixel spatiotemporal progression of focal ischemia derived using quantitative perfusion and diffusion imaging. Neurology Publications. https://doi.org/10.1097/01.WCB.0000100064.36077.03. Retrieved from https://escholarship.umassmed.edu/neuro_pp/108