Fig. 1.

56-years old woman 6 days after subarachnoid hemorrhage due to rupture of aneurysm of the posterior cerebral communicating artery. a Digital subtraction angiography shows severe vasospasm of distal M1 segment of the middle cerebral and A1 segment of the anterior cerebral artery. b Transcranial color coded duplex sonography shows the spastic M1 segment in blue (aliasing artifact), which enables for the operator to place the sample volume precisely at the place of the highest velocity acceleration and correct for the angle of insonation, which is substantial—43°. Mean flow velocity is 393 cm/s after correction for the angle. The finding corresponds to patient’s hemiplegia