gms | German Medical Science

Objective: Similar to its application with the middle cerebral artery (MCA), transcranial Doppler sonography (TCD) has also been shown to detect vasospasm of the basilar artery (BA) in patients with subarachnoid hemorrhage (SAH) with high specificity and lower sensitivity. However, TCD of the BA is challenging and requires a high level of experience. The aim of this study was to test the feasibility of the use of image guidance to perform image-guided TCD exams of the BA in SAH patients.

Methods: SAH patients who had undergone computed tomography angiography (CTA) at hospital admission were included. CTA Dicom data were taken to generate a treatment plan (Iplan software, Brainlab AG, Feldkirchen, Germany). TCD trajectories were planned through the suboccipital and temporal sonic windows to the following vascular targets: proximal and distal BA, vertebral arteries (VA), MCA, anterior and posterior cerebral arteries (ACA, PCA). The Kolibri image-guidance system with TCD software (Brainlab AG) was used to register the positions of patient’s head and Doppler probe (DWL, Singen, Germany) non-invasively. To analyze spatial precision of image-guided TCD, an intraprocedural trajectory was registered at the position of the optimal Doppler signal to determine the distance between position of optimal Doppler signal and preplanned trajectory. To examine spatial reproducibility, the distance between the intraprocedural trajectories obtained during the first exam and those during the following serial examinations was analyzed.

Results: 10 patients were included, all of who received 5 serial TCD exams. In all patients, TCD examination of all predefined supra- and infratentorial vessel segments were possible. The deviation between preplanned position and optimal Doppler signal representing spatial precision for BA (6.3±3.0 mm) was larger compared to left VA (4.1±2.2 mm), right VA (4.6±1.1 mm), and supratentorial vessels (4.8±1.9 mm). Furthermore, the deviation between the optimal Doppler signal at the first exam and the following serial exams for BA (6.9±3.5 mm), left VA (4.4±1.9 mm) and right VA (4.9±1.9 mm) were larger compared to the supratentorial vessels (3.3±1.7 mm).

Conclusion: Image-guided TCD of the BA is feasible. Although its spatial accuracy was lower when compared to the examination of supratentorial vascular targets, it is sufficient to perform precise and reproducible TCD examinations of the infatentorial vessels in the setting of vasospasm monitoring after SAH.