Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques--frequency- or power-based Doppler and contrast enhancement.
The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30% of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml SHU 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7% higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20% higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9%) could not be shown using TCCD.
Department of Neurology, Ernst Moritz Arndt University of Greifswald, Germany. griewing@neurologie.uni-greifswald.de
B
B
Griewing
U
U
Schminke
L
L
Motsch
F
F
Brassel
C
C
Kessler
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial
D003287:Contrast Media