Image quality of the temporal bone window examined by transcranial Doppler sonography and correlation with postmortem computed tomography measurements.
OBJECTIVE
The major limitation of native transcranial colour-coded duplex sonography (TCCS) in older stroke patients is the relatively frequent occurrence of an insufficient temporal window. Our goal was to investigate the relationship between the in vivo Doppler ultrasound image quality of the temporal bone, and computed tomography (CT)-determined thickness, density, and homogeneity of cadaver temporal bone.


METHODS
Thirty-three moribund neurological patients who eventually died were examined by TCCS using the transtemporal approach. The sonographer categorized the quality of the TCCS image (excellent, intermediate, and poor). During autopsy, a rectangular sample of the temporal squama was removed, which corresponded to the area of the in vivo acoustic window. The thickness of the whole temporal bone, cortical, and cancellous (= diploe) bone as well as the density and homogeneity were determined by high-resolution CT.


RESULTS
Thirty-seven temporal bones were obtained. The quality of the acoustic window was classified as excellent in 13, intermediate in 6 and poor in 18 cases. A significant correlation between the complete bone thickness, as well as between the absolute thickness of the diploe and the quality of the acoustic window was found: the thinner the bone/diploe, the better the colour Doppler signal. The thickness of the cortical plates and the homogeneity of the bones were identical in the three image quality categories.


CONCLUSIONS
The transtemporal TCCS image quality depends mainly on the thickness of the cancellous component of the temporal bone.
Kollár
József
J
Department of Radiology, Medical and Health Science Centre, Faculty of Medicine, University of Debrecen, Hungary. KJO@radiologia.doe.hu
Schulte-Altedorneburg
Gernot
G
Sikula
Judit
J
Fülesdi
Béla
B
Ringelstein
E Bernd
EB
Mehta
Vineet
V
Csiba
László
L
Droste
Dirk W
DW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial