Patient-Specific Computational Hemodynamics of Intracranial Aneurysms from 3D Rotational Angiography and CT Angiography: An In Vivo Reproducibility Study

• Published in: American journal of neuroradiology : AJNR 2011-03, Vol.32 (3), p.581-586
• Main Authors: GEERS, A. J, LARRABIDE, I, RADAELLI, A. G, BOGUNOVIC, H, KIM, M, GRATAMA VAN ANDEL, H. A. F, MAJOIE, C. B, VANBAVEL, E, FRANGI, A. F
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aneurismes cerebrals; Angiografia - Tècniques digitals; Biological and medical sciences; Blood Flow Velocity; Cerebral Angiography - methods; Cerebrovascular Circulation; Computer Simulation; Female; Fundamental and applied biological sciences. Psychology; Hemodinàmica; Human; Humans; Interventional; Intracranial Aneurysm - diagnostic imaging; Intracranial Aneurysm - physiopathology; Investigative techniques, diagnostic techniques (general aspects); Learning. Memory; Male; Medical sciences; Memory; Middle Aged; Models, Cardiovascular; Nervous system; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Radiographic Image Interpretation, Computer-Assisted - methods; Reproducibility of Results; Rotation; Sensitivity and Specificity; Tomography, X-Ray Computed - methods
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.a2306

Patient-specific simulations of the hemodynamics in intracranial aneurysms can be constructed by using image-based vascular models and CFD techniques. This work evaluates the impact of the choice of imaging technique on these simulations. Ten aneurysms, imaged with 3DRA and CTA, were analyzed to assess the reproducibility of geometric and hemodynamic variables across the 2 modalities. Compared with 3DRA models, we found that CTA models often had larger aneurysm necks (P = .05) and that most of the smallest vessels (between 0.7 and 1.0 mm in diameter) could not be reconstructed successfully with CTA. With respect to the values measured in the 3DRA models, the flow rate differed by 14.1 ± 2.8% (mean ± SE) just proximal to the aneurysm and 33.9 ± 7.6% at the aneurysm neck. The mean WSS on the aneurysm differed by 44.2 ± 6.0%. Even when normalized to the parent vessel WSS, a difference of 31.4 ± 9.9% remained, with the normalized WSS in most cases being larger in the CTA model (P = .04). Despite these substantial differences, excellent agreement (κ ≥ 0.9) was found for qualitative variables that describe the flow field, such as the structure of the flow pattern and the flow complexity. Although relatively large differences were found for all evaluated quantitative hemodynamic variables, the main flow characteristics were reproduced across imaging modalities.