The hemodynamics of intracranial aneurysm by transcranial Doppler arteriography
Tsujimoto, S.; Takeshima, T.; Sakai, T.; Yokoyama, K.; Okumura, Y.; Nagata, K.; Sawai, F.
No Shinkei Geka. Neurological Surgery 20(5): 541-546
1992
ISSN/ISBN: 0301-2603 PMID: 1598129 Document Number: 393235
The use of an ultrasonic transcranial Doppler arteriography (TCDA) technique for noninvasive diagnosis of cerebral aneurysm is described. Twenty one patients with intracranial aneurysm previously diagnosed by conventional angiography were evaluated with Trans-Scan (EME). Mapping image was used as a guide to identify parent artery and aneurysm. In four patients, we could not record aneurysmal blood flow because of their poor or non existent acoustic window. Good images were recorded in 17 patients. The location of aneurysms were A-com (1 case), Distal ACA (2 cases), IC (7 cases), MCA (3 cases), Basilar (1 case) and IC fusiform (3 cases). Two types of Doppler spectra were obtained from the aneurysmal blood flow. One was characterized by a high density zone along the base line and the other was characterized by a homogeneous high density zone. In both types, Doppler sound was characterized by low frequency sound. The low frequency sound reflects the turbulent flow in the aneurysm. The pattern of Doppler spectra obtained from ordinary arteries was characterized by a high density zone along the descending limb of the envelope. Doppler sound is characterized by high frequency sound. A homogeneous spectral pattern was obtained in both aneurysms and ordinary arteries. But it was possible to differentiate them by Doppler sound. Consequently to be able to bear Doppler sound is very important. We were able to detect fourteen of seventeen aneurysms (A-com 1/1, Distal ACA 1/2, IC 7/7, MCA 2/3, Basilar 1/1, and IC fusiform 2/3). The rate of detection was 82 percent. Aneurysm size ranged from 5 mm .times. 4 mm to 16 mm .times. 18 mm. The maximum diameter of the smallest aneurysms we could detect was 5 mm in 4 cases. We expect TCDA, to become a good means, for a noninvasive examination to detect intracranial aneurysms.