Transcranial Doppler monitoring of blood flow in the middle cerebral artery during angiography and drug perfusion.

With the new technique of transcranial Doppler sonography it is possible to record transient changes of blood flow within the major basal cerebral arteries. The injection of saline and contrast medium into the internal carotid artery is followed immediately by a marked turbulence of flow within the middle cerebral artery depending on the amount and pressure of the injected material. In addition, the flow in the middle cerebral artery is increased by the injection of saline, but reduced by the injection of contrast medium for 3 to 4 seconds and finally increased for 8 to 10 seconds. No changes are seen on the contralateral side. The recordings of blood flow within the middle cerebral artery during 1.3-bis(2-chlorethyl)nitrosurea (BCNU) perfusion of glioblastoma recurrences via a flow-directed balloon catheter showed no obvious alterations during injections into the upper part of the carotid siphon, but a marked reduction of diastolic flow during injections into the middle cerebral artery. The reduction of flow may explain some of the complications of angiography.