Importance of Angle Correction in the Measurement of Blood Flow Velocity with Transcranial Doppler Sonography
Jaroslaw Krejzaa,
Zenon Mariaka and
Viken L. Babikiana
a From the Department of Radiology (J.K., Z.M.), Bialystok Medical Academy, Bialystok, Poland, and the Department of Neurology (V.L.B.), Boston University School of Medicine, MA.
View larger version (58K):
[in a new window]
|
FIG 1. Comparison between angle-corrected and uncorrected flow velocities and angiographic findings in a 54-year-old woman with MCA stenosis.
A and B, At TCCD sonography, the sample volume is placed approximately 10 mm from the internal carotid artery bifurcation and within the color image of the right MCA. The velocity spectrum is adjacent to the left of the image of the artery. The uncorrected peak systolic velocity is 149 cm/s (B).
C, Angiogram shows a lesion causing a stenosis of more than 50% (arrow) in the right MCA M1 segment. The angle-corrected peak systolic velocity is 204 cm/s.
| |
View larger version (70K):
[in a new window]
|
FIG 2. Mass effect and arterial displacement from intracerebral hemorrhage.
A, Brain CT scan in a 50-year-old man shows an intraparenchymal hematoma with a relatively limited mass effect on the basal cerebral cisterns.
B, A 3D CT reconstruction illustrates the relationships between the MCA, the temporal sonographic window (W) and direction of the ultrasound beam direction (arrow), and the lesser sphenoid wing (arrowheads). When compared with the contralateral MCA, the hematoma has displaced the ipsilateral MCA toward the skull base.
| |
