Magnetic resonance angiography (MRA) and transcranial doppler (TCD) are two non-invasive techinques to assess the state cerebral vasculature. Aim of the study: to compare the information obtained by these two modes of investigation for the assessment of intracranial hemodynamics in cases of acute ischemic stroke. Material and methods: we studied 58 patients with acute ischemic stroke by MRI, MRA on admission. TCD was performed at a maximum time interval of 24 hours from MRA. Results: 69% of vessels attenuated on MRA were normal by TCD, 52.5% athersclerotic on MRA were normal by TCD, 40% stenotic on MRA showed normal flow by TCD. Also, 64.7% with different grades of occlusion on MRA showed stenosis and only 11.7% showed occlusion on TCD while 23.6% had intact flow. One ICA showing dissection by MRA and angiography was reported as stenotic by TCD. Conclusion: MRA better depicted vascular anatomy and pathology as atherosclerosis and dissection, while TCD was better in detection of the hemodynamic effect of stenosis, and collateral circulation in terms of cross filling. Recommendations: In acute ischemic stroke MRI/ MRA can be the starting investigation to determine the pathological state of blood vessels and to decide on the appropriate mode of therapy. TCD is subsequently performed to estimate vascular hemodynamics, state of collateralization, follow up the effect of therapeutic intervention. In selected cases which remain doubtful PC MRA can be performed at different chosen velocities to detect complete occlusion versus slow flow. Applying the collapsed image in MRA and reporting on stenotic segments even if less than 50% of normal calibre.-Employing transcranial colour coded duplex when available.
(Egypt J. Neurol. Psychiat. Neurosurg., 2004, 41(2): 459-478).