Detection of intracranial aneurysms with unenhanced and echo contrast enhanced transcranial power Doppler

Objective-To assess transcranial power Doppler and the effect of an intrave nous ultrasonic contrast agent for detecting intracranial aneurysms in pati ents admitted with a subarachnoid haemorrhage Methods-203 patients with subarachnoid haemorrhage were examined with the o perator blind to the results of the admission CT and subsequent digital sub traction angiogram (DSA). In 98 cases patients were imaged using unenhanced transcranial power Doppler, and in 105 cases, patients were imaged both us ing unenhanced and echo contrast enhanced (Levovist, Schering AG) transcran ial power Doppler. Results-DSA detected 168 intracranial aneurysms in 128 patients (24 patient s had multiple lesions) and 75 patients had an aneurysm negative DSA. There was agreement between DSA and transcranial power Doppler in 87 intracrania l aneurysms of which 20 were only detected after infusion of contrast agent . Without contrast infusion, transcranial power Doppler showed a sensitivit y of 40% and specificity of 91%. A significant increase in detection was no ted when using a contrast agent (X-2=9.49, p<0.001). With a contrast study the sensitivity increased to 55% with a specificity of 83%. Intracranial an eurysm detection by transcranial power Doppler was significantly dependent on position using a contrast infusion (X-2=15.87, p<0.05). A positive corre lation was also found between the size of intracranial aneurysms measured b y transcranial power Doppler and DSA (r=0.55, p<0.05). The transcranial pow er Doppler sensitivity and specificity increased with larger aneurysms and reached 100% for intracranial aneurysms greater than 12 mm diameter. Detect ion by transcranial power Doppler was also dependent on morphology (X-2=14. 46, p<0.001). Conclusions-The detection of intracranial aneurysm by transcranial power Do ppler is dependent on aneurysm location, size, and morphology and is enhanc ed with the use of an intravenous contrast agent.