The Horizontal Angle of the Middle Cerebral Artery from the Middle TCD Temporal Window

Abstract

Transcranial Doppler (TCD)is a common test used for cerebrovascular diseases. Typically, TCDs are done blindly, with no angle correction for any of the intracranial arteries. The authors measured the angle of the middle cerebral artery (MCA), as seen from the middle temporal sono-graphic window, on computed tomography (CT) scans of the brain. The head CT scans of 100 random adult patients were studied. The angles were measured once on each side by two blinded readers, with 200 measurements per reader, for a total of 400 measured angles. The mean angle of the MCA, as seen from the middle temporal window, is 33.9 degrees. There was no statistical difference between readers. When interrogating the MCA with TCD via the middle temporal sonographic window, it seems appropriate to use a 30-degree angle correction. More research needs to be done to determine the clinical utility of this finding.

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