- Title
- Comparison of computed tomography perfusion and magnetic resonance imaging perfusion-diffusion mismatch in ischemic stroke
- Creator
- Campbell, Bruce C. V.; Christensen, Søren; Levi, Christopher R.; Desmond, Patricia M.; Donnan, Geoffrey A.; Davis, Stephen M.; Parsons, Mark W.
- Relation
- Stroke Vol. 43, Issue 10, p. 2648-2653
- Publisher Link
- http://dx.doi.org/10.1161/STROKEAHA.112.660548
- Publisher
- Lippincott Williams & Wilkins
- Resource Type
- journal article
- Date
- 2012
- Description
- Background and Purpose: Perfusion imaging has the potential to select patients most likely to respond to thrombolysis. We tested the correspondence of computed tomography perfusion (CTP)-derived mismatch with contemporaneous perfusion-diffusion magnetic resonance imaging (MRI). Methods: Acute ischemic stroke patients 3 to 6 hours after onset had CTP and perfusion-diffusion MRI within 1 hour, before thrombolysis. Relative cerebral blood flow (relCBF) and time to peak of the deconvolved tissue residue function (Tmax) were calculated. The diffusion lesion (diffusion-weighted imaging) was registered to the CTP slabs and manually outlined to its maximal visual extent. Volumetric accuracy of CT-relCBF infarct core (compared with diffusion-weighted imaging) was tested. To reduce false-positive low CBF regions, relCBF core was restricted to voxels within a relative time-to-peak (relTTP) >4 seconds for lesion region of interest. The MR-Tmax >6 seconds perfusion lesion was automatically segmented and registered to CTP. Receiver-operating characteristic analysis determined the optimal CT-Tmax threshold to match MR-Tmax >6 seconds. Agreement of these CT parameters with MR perfusion-diffusion mismatch in coregistered slabs was assessed (mismatch ratio >1.2, absolute mismatch >10 mL, infarct core <70 mL). Results: In analysis of 49 patients (mean onset to CT, 213 minutes; mean CT to MR, 31 minutes), constraining relCBF <31% within the automated relTTP perfusion lesion region of interest reduced the median magnitude of volumetric error (vs diffusion-weighted imaging) from 47.5 mL to 15.8 mL (P<0.001). The optimal CT-Tmax threshold to match MR-Tmax >6 seconds was 6.2 seconds (95% confidence interval, 5.6–7.3 seconds; sensitivity, 91%; specificity, 70%; area under the curve, 0.87). Using CT-Tmax >6 seconds “penumbra” and relTTP-constrained relCBF “core,” CT-based and MRI-based mismatch status was concordant in 90% (kappa=0.80). Conclusions: Quantitative CTP mismatch classification using relCBF and Tmax is similar to perfusion-diffusion MRI. The greater accessibility of CTP may facilitate generalizability of mismatch-based selection in clinical practice and trials.
- Subject
- acute stroke; computed tomography imaging; ischemia; magnetic resonance imaging; perfusion
- Identifier
- http://hdl.handle.net/1959.13/1306247
- Identifier
- uon:21179
- Identifier
- ISSN:0039-2499
- Language
- eng
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