Transcranial Doppler sonography (TCD) is widely used in neurointensive care. Image guidance (IG) could simplify secure vessel identification and reduce interinvestigator and intrainvestigator variability. The present study was purposed to investigate the precision and reproducibility of image-guided TCD.
The Kolibri IG system (Brainlab AG, Feldkirchen, Germany) was used to track a hand-held Doppler probe of a DWL Multi-Dop® T digital device (Compumedics Germany GmbH, Singen, Germany). The patient’s head was registered noninvasively to the IG system. Distance between predefined vascular target and optimal Doppler signal was evaluated to assess spatial accuracy of image-guided TCD. To investigate reproducibility, spatial accuracy of trajectories acquired during an initial examination using the IG system was analyzed in serial examinations. Furthermore, stability of noninvasive registration of the patient’s head to the IG system was analyzed. Data are presented as mean±SD for descriptive statistics. Twelve patients were included.
Using IG, a Doppler signal was recorded immediately in all cases for middle cerebral artery (MCA) (29 examinations), in 81% for carotid-T (27 examinations), and in 90% for basilar tip (29 examinations). The optimal Doppler signal was found within 2.64±1.15 mm (94 preplanned targets). At serial examinations, a spatial deviation of 2.75±1.20 mm was found (56 trajectories acquired in 19 serial examinations). Examination time did not influence accuracy of noninvasive patient registration.
Data suggest that image-guided TCD allows for accurate examinations with high intraprocedural and high interprocedural reproducibility. It facilitates identification of specific vessel segments and generation of standardized examination protocols for serial examinations.
*Department of Neurosurgery, Georg-August-University of Goettingen, Goettingen
†Department of Neurosurgery, Johannes-Gutenberg-University of Mainz, Mainz
‡Compumedics Germany GmbH, Singen
§Brainlab AG, Feldkirchen, Germany
C.G. and A.N. contributed equally.
F.C.V. and I.T. are employees of Brainlab AG (Feldkirchen, Germany), which developed and sells the navigation system used in this study. A.B. is an employee of Compumedics Germany GmbH (Singen, Germany), which developed and sells the DWL Doppler device used in this study. TCD hardware and TCD software were provided by the respective companies. Brainlab AG provided funds to the University of Goettingen for temporary employment of a research fellow at the neurosurgical department. Apart from the above-mentioned employee status, the remaining authors have no personal financial or institutional interest in any of the drugs, materials, or devices described in this article.
Reprints: Alf Giese, MD, Department of Neurosurgery, Johannes-Gutenberg-University, Langenbeckstr. 1, Mainz 55131, Germany (e-mail: email@example.com).
Received January 26, 2012
Accepted July 23, 2012