Image guidance to improve reliability and data integrity of transcranial Doppler sonography.
BACKGROUND
Principles and accuracy of image-guided transcranial Doppler (IG TCD) sonography have been published recently. However, it remains open whether combination of image guidance and TCD offers an additional clinical advantage. This study scores the accuracy of conventional TCD examinations and investigates the potential improvement of TCD data integrity and reliability regarding the additional use of IG.


METHODS
Conventional TCD was performed by a group of experienced investigators, who were blinded to images of a navigation system tracking the Doppler probe, whereas an independent observer documented the TCD findings, acquired by the investigators, due to saving spatial data of the TCD sample volume using IG for subsequent analysis. In a second set of experiments, image guidance was available to investigators without any previous TCD experience.


RESULTS
The analysis of 3D data of vessels (n=173) labeled by experienced investigators in conventional TCD, revealed a rate of 37% misinterpreted Doppler signals regarding the target vessel. Correctness of labeling was comparable between the different vascular segments. The rate of correct labeling was higher for right- (69%) than for left-sided vessels (57%). In comparison, by using IG, TCD investigators without any previous TCD experience achieved a significantly lower rate of 10% (n=39) mislabeled vessels.


CONCLUSIONS
Our data suggest, that misinterpretation of the vascular source of the Doppler signal is a common source of errors in conventional TCD. Visualization of the vascular anatomy by image guidance offers improved accuracy and reliability of TCD results and may positively influence the learning curve for inexperienced investigators.
Department of Neurosurgery, University Medical Center, Johannes Gutenberg-University of Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany.
Axel
A
Neulen
Christian
C
Greke
Esther
E
Prokesch
Jochem
J
König
Daniel
D
Wertheimer
Alf
A
Giese
D000368:Aged; D002533:Cerebral Angiography; D003625:Data Collection / Q000592:standards; D004108:Dilatation, Pathologic / Q000209:etiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000601:surgery; D015912:Thrombolytic Therapy; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging
Acoustic window; Bone window; ICU; Image guidance; Neurointensive care; Neuronavigation; Neurovascular diseases; Sonothrombolysis; TCD; Transcranial Doppler sonography; Ultrasound; Vasospasm