Computational Fluid Dynamics Analysis of Contrast Agent Distribution in Acute Large Artery Occlusive Stroke: A Preliminary Proof-of-Concept Study

Background: Acute ischemic stroke (AIS) resulting from carotid artery occlusion (CAO) represents a significant clinical challenge because conventional imaging modalities often lead to inaccuracies in occlusion length assessment, potentially compromising therapeutic decision-making. We aimed to analyze the distribution patterns of contrast agents using computational fluid dynamics (CFD) simulations in AIS caused by CAO and to mitigate errors in estimating occlusion length. Methods: Data from four patients with AIS caused by CAO were analyzed. CFD simulations were conducted using postoperative computed tomography angiography (CTA) data to model contrast agent flow, and the results were compared with those of preoperative CTA and intraoperative digital subtraction angiography (DSA). Results: CTA/DSA demonstrated a flame sign at the ICA origin in Patients 1–3. Patients 1 and 2 had carotid dissection, whereas Patient 3 had a C4-segment embolic occlusion. In Patient 3, DSA showed C1-origin vortices, a horizontal contrast–blood interface, and no distal C1 opacification, features distinct from those in Patients 1 and 2. CFD simulations using the post-recanalization CTA model replicated this contrast distribution, including the vortices and interface; proximal C1 vortex ranges, velocities, pressures, and wall shear stress were comparable, but the mass-weighted average velocity varied over time. Conclusions: CFD simulations recreated contrast agent distribution during C4 segment occlusion, revealing a high-pressure dead space in the distal C1 segment. This study generated preliminary evidence for understanding contrast agent distribution in CAOs, offering valuable insights for clinical imaging assessments.