Cerebral perfusion in corresponding blood supply areas of transient ischemic attack patients with intracranial stenosis Seven cases of diamox-perfusion verified by magnetic resonance-perfusion-weighted imaging

BACKGROUND： Due to collateral circulation and cerebrovascular reserve, arterial stenosis and reduced cerebral blood flow may not necessarily indicate impaired cerebral peffusion. Therefore, according to degree of stenosis and clinical symptoms, interventional surgery to relieve arterial stenosis in transient ischemic attack （TIA） patients with major intracranial stenosis is imprudent. Rather, cerebral perfusion and reserve capacity are direct indicators for the assessment of degree and presence of cerebral ischemia. OBJECTIVE： To evaluate cerebral perfusion and reserve in TIA patients with major intracranial stenosis or occlusion using magnetic resonance-perfusion-weighted imaging （MR-PWl） data prior to and following diamox administration. DESIGN, TIME AND SETTING： A self-comparative, neuroimaging observation was performed at the Neurological Department and Radiological Center of the First Affiliated Hospital of Jinan University between December 2007 and April 2009. PARTICIPANTS： Seven acute TIA patients, who were admitted to the Neurological Department of the First Affiliated Hospital of Jinan University between December 2007 and April 2009, were enrolled in the present study. Magnetic resonance imaging confirmed that no acute cerebral infarction happened, nor did bleeding exist. Magnetic resonance angiography, transcranial Doppler ultrasound, and/or digital subtraction angiography confirmed the presence of major intracranial arterial stenosis. Clinical symptoms corresponded to blood supplying regions of the arterial stenosis. METHODS： Baseline MR-PWI was performed on seven patients with intracranial stenosis or occlusion. Two grams of acetazolamide （diamox） were orally administered after 2 days. A second PWl was performed after 2 hours to compare cerebral perfusion parameters prior to and following diamox administration. MAIN OUTCOME MEASURES： PWI results of cerebral perfusion prior to and following diamox administration. RESULTS： The baseline PWl from five patients indicated decreased cerebral perfusion areas. Following oral administration of diamox, cerebral perfusion significantly decreased in those areas. Moreover, new areas of decreased cerebral perfusion were observed in two out of the five patients. In one patient, no significant decrease in cerebral perfusion was found. In another patient, baseline PWl indicated decreased cerebral perfusion in the left hemisphere. However, normal perfusion was observed in both cerebral lobes following diamox administration. CONCLUSION： TIA patients with intracranial stenosis, who are diagnosed by PWI and exhibited decreased cerebral perfusion and reserve, might require further treatment such as intervention by angioptasty.

Magnetic resonance perfusion imaging evaluation in perfusion abnormalities of the cerebellum after supratentorial unilateral hyperacute cerebral infarction

Magnetic resonance imaging （MRI） data of 10 patients with hyperacute cerebral infarction （≤6 hours） were retrospectively analyzed.Six patients exhibited perfusion defects on negative enhancement integral maps,four patients exhibited perfusion differences in pseudo-color on mean time to enhance maps,and three patients exhibited perfusion differences in pseudo-color on time to minimum maps.Dynamic susceptibility contrast-enhanced perfusion weighted imaging revealed a significant increase in region negative enhancement integral in the affected hemisphere of patients with cerebral infarction.The results suggest that dynamic susceptibility contrast-enhanced perfusion weighted imaging can clearly detect perfusion abnormalities in the cerebellum after unilateral hyperacute cerebral infarction.