Transcranial Doppler ultrasonography: influence on scheduling of angiography and delayed surgery for ruptured intracranial aneurysms.

The role of transcranial Doppler ultrasound (TCD) was studied retrospectively in relation to the management of 73 patients with a subarachnoid hemorrhage due to a ruptured intracranial aneurysms. TCD velocity measurements provided very valuable data to assist scheduling of angiography and delayed surgery. Angiography and surgery were planned significantly sooner in the TCD examined group of patients with TCD velocities indicative for the absence of vasospasm than in the group of patients who did not have TCD examinations. The cerebral circulatory resistance index (R), calculated as: (maximum systolic velocity--end diastolic velocity)/maximum systolic velocity, and changes in R did not predict a change in clinical grade or outcome.