Imaging cerebral arteries tortuosity and velocities by transcranial Doppler ultrasound is a reliable assessment of brain aneurysm in mouse models

Background and Purpose: Intracranial aneurysms (IAs) are common vascular abnormalities of the brain, with a prevalence of 3.2% in the general population. In the past few decades, several pathophysiological processes leading to IA rupture were identified, including irregular IA shape, an altered hemodynamic stress within the IA and vessel wall inflammation. The use of preclinical models of IA and imaging tools are paramount to better understand the underlying disease mechanisms. Therefore, there is a need for imaging methods to monitor intracranial aneurysm formation. Methods: We used two established mouse models of IA, and we analyzed the progression of the IA by magnetic resonance imaging (MRI), transcranial Doppler (TCD), and histological studies. Results: In both models of IA, we observed by TCD a significant decrease of the blood velocities and wall shear stress of the internal carotid arteries (ICA). We also observed the formation of tortuous arteries in both models, which were correlated with the presence of an aneurysm, as confirmed by MRI and histological analysis. A high grade of tortuosity has been associated with a significant decrease of the mean blood flow velocities and a greater artery dilation. Conclusions: TCD is a robust and easy imaging method to evaluate the progression of IA. The decrease of the blood flow velocities and the tortuosity can be used as reliable readout for IA detection. ### Competing Interest Statement The authors have declared no competing interest.