Gianvincenzo Sparacia MD, Presenter: Nothing to Disclose

Alberto Iaia MD, Abstract Co-Author: Nothing to Disclose

Assadi Bahareh MD, Abstract Co-Author: Nothing to Disclose

Roberto Lagalla, Abstract Co-Author: Nothing to Disclose

To asses diffusion-weighted imaging (DWI) / multiphasic perfusion computed tomography (CTP) mismatch in hyperacute stroke.

Ten patients (mean age 63.3 years) with nonlacunar ischemic stroke were imaged with DWI and CTP within 6 hours of symptom onset. Follow up T2-weighted MR imaging after 1 week was obtained in 5 out of 10 patients. CTP images were acquired at the basal ganglia over 40 secs, during injection of 90ml of Optiray 320, injected at 9 ml/sec with a 9 sec delay. Z-axis coverage was 20 mm. The volume of region with mean-transit-time (MTT) threshold delay of 6.5 seconds at CTP was measured; this volume was compared with the acute DWI lesion volume in 10 patients and with final infarct size on T2-weigted images in 5 patients. Statistical analysis was performed by using a 1-way ANOVA test to assess differences in CTP-DWI volume in 10 patients and in CTP, DWI and T2-weighted imaging volume in 5 patients. A correlation analysis to assess the association between the volume of the regions with CTP MTT delays of >= 6.5s and 1) the volume of lesions on DWI images in 10 patients and 2) on T2-weighted imaging in 5 patients was performed.

In all patients the acute DWI lesion was surrounded by regions with abnormal CTP MTT delays (CTP MTT>DWI volume lesion, P =6.5 s was larger than the DWI lesion volume (P < .001), which indicated that a CTP MTT delay of 6.5 seconds might be the threshold for functional impairment of brain tissue.

Patients with severe CTP/DWI mismatch (MTT delays of >=6.5 s) are at high risk of lesion enlargement.

Sparacia, G, Iaia, A, Bahareh, A, Lagalla, R, Diffusion-weighted Imaging/Multiphasic Perfusion Computed Tomography Mismatch in Hyperacute Stroke.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4416797.html