TY - JOUR T1 - Patient-Specific Computational Hemodynamics of Intracranial Aneurysms from 3D Rotational Angiography and CT Angiography: An In Vivo Reproducibility Study JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 581 LP - 586 DO - 10.3174/ajnr.A2306 VL - 32 IS - 3 AU - A.J. Geers AU - I. Larrabide AU - A.G. Radaelli AU - H. Bogunovic AU - M. Kim AU - H.A.F. Gratama van Andel AU - C.B. Majoie AU - E. VanBavel AU - A.F. Frangi Y1 - 2011/03/01 UR - http://www.ajnr.org/content/32/3/581.abstract N2 - BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: Ten aneurysms, imaged with 3DRA and CTA, were analyzed to assess the reproducibility of geometric and hemodynamic variables across the 2 modalities. RESULTS: 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. CONCLUSIONS: Although relatively large differences were found for all evaluated quantitative hemodynamic variables, the main flow characteristics were reproduced across imaging modalities. 3DRA3D rotational angiographyACAanterior cerebral arteryANaneurysm neck areaBAbasilar arteryCFDcomputational fluid dynamicsCTACT angiographyΔrelative difference between the 3DRA and CTA models with respect to the 3DRA modelICAinternal carotid arteryLWSSAthe portion of aneurysm wall under low WSS (<0.4 Pa) at end diastoleMnumber of cases for which the value in the CTA model was lower than in the 3DRA modelMCAmiddle cerebral arteryMCA M1MCA M1 segmentMCA M1-M2MCA M1-M2 bifurcationMWSSAmaximum WSS on the aneurysm wall at peak systoleNQAQA/QPNWSSAWSSA/WSSPN90WSSA90WSSA normalized by the mean WSS on the aneurysm at peak systoleOSIoscillatory shear indexQAflow rate into the aneurysmQPflow rate in the parent vessel just proximal to the aneurysmSEstandard errorVAvertebral arteryVAaneurysm volume90WSSA90th percentile value of the WSS on the aneurysm at peak systoleWSSwall shear stressWSSAmean WSS on the aneurysm wallWSSPmean WSS on a segment of the parent vessel just proximal to the aneurysm ER -