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A comparison of images generated from diffusion‐weighted and diffusion‐tensor imaging data in hyper‐acute stroke
Author(s) -
Harris Ashley D.,
Pereira Raoul S.,
Mitchell J. Ross,
Hill Michael D.,
Sevick Robert J.,
Frayne Richard
Publication year - 2004
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20116
Subject(s) - diffusion mri , fractional anisotropy , effective diffusion coefficient , medicine , anisotropy , stroke (engine) , magnetic resonance imaging , isotropy , acute stroke , nuclear medicine , diffusion , nuclear magnetic resonance , radiology , physics , optics , tissue plasminogen activator , thermodynamics
Purpose To compare isotropic (combined diffusion‐weighted image [CMB], apparent diffusion coefficient [ADC], TRACE, exponential ADC [eADC], and isotropically‐weighted diffusion image [isoDWI]) and anisotropic (relative anisotropy [RA], fractional anisotropy [FA], and volume ratio [VR]) diffusion images collected with fast magnetic resonance (MR) diffusion‐weighted (DWI) and diffusion‐tensor (DTI) acquisition strategies (each less than one minute) in hyper‐acute stroke. Materials and Methods Twenty‐one patients suffering from ischemic stroke—imaged within six hours of symptom onset using both DWI and DTI—were analyzed. Regions of interest were placed in the ischemic lesion and in normal contralateral tissue and the percent difference in image intensity was calculated for all nine generated images. Results The average absolute percent changes for the isotropic strategies were all > 38%, with isoDWI found to have a difference of 50.7% ± 7.9% (mean ± standard error, P < 0.001). The ADC maps had the most significant difference (–42.4% ± 2.0%, P < 0.001, coefficient of variation = 0.22). No anisotropic images had significant differences. Conclusion Anisotropic maps do not consistently show changes in the first six hours of ischemic stroke; therefore, isotropic maps, such as those obtained using DWI, are more appropriate for detecting hyper‐acute stroke. Anisotropic images, however, may be useful to differentiate hyper‐acute stroke from acute and sub‐acute stroke. J. Magn. Reson. Imaging 2004;20:193–200. © 2004 Wiley‐Liss, Inc.