Detection of ischemic penumbra using combined perfusion and T2* oxygen challenge imaging

Robertson, C. A., McCabe, C. , Lopez-Gonzalez, M. R., Deuchar, G. A., Dani, K., Holmes, W. M. , Muir, K. W. , Santosh, C. and Macrae, I. M. (2014) Detection of ischemic penumbra using combined perfusion and T2* oxygen challenge imaging. International Journal of Stroke, 10(1), pp. 42-50. (doi:10.1111/ijs.12327)

[img]
Preview
Text
96397.pdf - Published Version
Available under License Creative Commons Attribution.

1MB

Publisher's URL: http://dx.doi.org/10.1111/ijs.12327

Abstract

<b>Background</b> Acute ischemic stroke is common and disabling, but there remains a paucity of acute treatment options and available treatment (thrombolysis) is underutilized. Advanced brain imaging, designed to identify viable hypoperfused tissue (penumbra), could target treatment to a wider population. Existing magnetic resonance imaging and computed tomography-based technologies are not widely used pending validation in ongoing clinical trials. T2* oxygen challenge magnetic resonance imaging, by providing a more direct readout of tissue viability, has the potential to identify more patients likely to benefit from thrombolysis – irrespective of time from stroke onset – and patients within and beyond the 4•5 h thrombolysis treatment window who are unlikely to benefit and are at an increased risk of hemorrhage.<p></p> <b>Aims</b> This study employs serial multimodal imaging and voxel-based analysis to develop optimal data processing for T2* oxygen challenge penumbra assessment. Tissue in the ischemic hemisphere is compartmentalized into penumbra, ischemic core, or normal using T2* oxygen challenge (single threshold) or T2* oxygen challenge plus cerebral blood flow (dual threshold) data. Penumbra defined by perfusion imaging/apparent diffusion coefficient mismatch (dual threshold) is included for comparison.<p></p> <b>Methods</b> Permanent middle cerebral artery occlusion was induced in male Sprague-Dawley rats (<i>n</i> = 6) prior to serial multimodal imaging: T2* oxygen challenge, diffusion-weighted and perfusion imaging (cerebral blood flow using arterial spin labeling).<p></p> <b>Results</b> Across the different methods evaluated, T2* oxygen challenge combined with perfusion imaging most closely predicted 24 h infarct volume. Penumbra volume declined from one to four-hours post-stroke: mean ± SD, 77 ± 44 to 49 ± 37 mm<sup>3</sup> (single T2* oxygen challenge-based threshold); 55 ± 41 to 37 ± 12  mm<sup>3</sup> (dual T2* oxygen challenge/cerebral blood flow); 84 ± 64 to 42 ± 18  mm<sup>3</sup> (dual cerebral blood flow/apparent diffusion coefficient), as ischemic core grew: 155 ± 37 to 211 ± 36  mm<sup>3</sup> (single apparent diffusion coefficient threshold); 178 ± 56 to 205 ± 33  mm<sup>3</sup> (dual T2* oxygen challenge/cerebral blood flow); 139 ± 30 to 168 ± 38  mm<sup>3</sup> (dual cerebral blood flow/apparent diffusion coefficient). There was evidence of further lesion growth beyond four-hours (T2-defined edema-corrected infarct, 231 ± 19 mm<sup>3</sup>).<p></p> <b>Conclusions</b> In conclusion, T2* oxygen challenge combined with perfusion imaging has advantages over alternative magnetic resonance imaging techniques for penumbra detection by providing serial assessment of available penumbra based on tissue viability.<p></p>

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Deuchar, Dr Graeme and Macrae, Professor I Mhairi and Holmes, Dr William and Muir, Professor Keith and Lopez Gonzalez, Dr Rosario and McCabe, Dr Chris and Dani, Dr Krishna and Santosh, Dr Celestine
Authors: Robertson, C. A., McCabe, C., Lopez-Gonzalez, M. R., Deuchar, G. A., Dani, K., Holmes, W. M., Muir, K. W., Santosh, C., and Macrae, I. M.
College/School:College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:International Journal of Stroke
Publisher:Wiley
ISSN:1747-4930
ISSN (Online):1747-4949
Copyright Holders:Copyright © 2014 The Authors
First Published:First published in International Journal of Stroke
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record