Xiang Liu MD, Presenter: Nothing to Disclose

Wei Tian MD, Abstract Co-Author: Nothing to Disclose

Per-Lennart Alwe Westesson MD, Abstract Co-Author: Nothing to Disclose

To evaluate and compare the diffusion tensor imaging(DTI) diffusion weighted imaging(DWI) manifestation of Wallerian degeneration(WD) by ischemic stroke.

16 volunteers and 44 scans of 29 patients, which ranged 11 hours to 1 year after MCA territory ischemic stroke onset, which involved cortical spinal tract(CST), were analyzed.13 patients accepted prospective series of DWI and DTI examination in GE Signa 3T. Fractional anisotropy(FA), Anistropy index(AI) of DTI and apparent diffusion coefficient(ADC) of DWI in ROIs of cerebral peduncle were calculated and compared. 3D tractography of bilateral CST in 22 patients were created by Volume DTV 1.2.

According to the time post stroke onset, all data were divided into 5 groups. Group 1: scans in the first week after stroke onset. Group 2: from 2 week to 4 weeks. Group 3: 5-14 weeks. Group 4: after 14 weeks. Combing with DWI and regular T2WI and FLAIR images, only 32 scans were diagnosed as WD. None of these 32 scans was in group 1. But on color FA and AI maps, the area of pyramidal tract in lesion side was smaller than contralateral side.In all groups, FA and AI values of cerebral peduncle in lesion side were lower than contralateral side cerebral peduncle, P<0.01 by paired t test. In group 1, ADC values of cerebral peduncle in lesion side were lower, P<0.01. In other groups, the ADC values between both side cerebral peduncles didn’t have significant difference. On 3D tractography of CSTs, the fiber tracts in the lesion side were thinner than contralateral side.

WD in acute, subacute and chronic phases of ischemic stroke could be observed on DTI images. DTI could detect Wallerian degeneration earlier and clearer than regular MRI and DWI by characteristic of decreasing anisotropy diffusion of cortical spinal tract. 3D tract map postprocessed from DTI data is useful observing the status of bilateral pyramid tracts stereotacticly. DTI is the optimum imaging method for diagnosing Wallerian degeneration in vivo.

Liu, X, Tian, W, Westesson, P, Diffusion Weighted and Diffusion Tensor Imaging of Wallerian Degeneration after Cerebral Ischemic Stroke in 3T.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4412518.html