Quantitative and Qualitative Comparison of 4D-DSA with 3D-DSA Using Computational Fluid Dynamics Simulations in Cerebral Aneurysms

摘要

BACKGROUND AND PURPOSE: 4D-DSA allows time-resolved 3D imaging of the cerebral vasculature. The aim of our study was to evaluate this method in comparison with the current criterion standard 3D-DSA by qualitative and quantitative means using computational fluid dynamics. MATERIALS AND METHODS: 3D- and 4D-DSA datasets were acquired in patients with cerebral aneurysms. Computational fluid dynamics analysis was performed for all datasets. Using computational fluid dynamics, we compared 4D-DSA with 3D-DSA in terms of both aneurysmal geometry (quantitative: maximum diameter, ostium size [OZ1/2], volume) and hemodynamic parameters (qualitative: flow stability, flow complexity, inflow concentration; quantitative: average/maximum wall shear stress, impingement zone, low-stress zone, intra-aneurysmal pressure, and flow velocity). Qualitative parameters were descriptively analyzed. Correlation coefficients (r, P value) were calculated for quantitative parameters. RESULTS: 3D- and 4D-DSA datasets of 10 cerebral aneurysms in 10 patients were postprocessed. Evaluation of aneurysmal geometry with 4D-DSA (r(maximum diameter) = 0.98, P-maximum diameter r(OZ1/OZ2) = 0.98/0.86, P-OZ1/OZ2 < .001/.002; r(volume) = 0.98, P-volume <.001) correlated highly with 3D-DSA. Evaluation of qualitative hemodynamic parameters (flow stability, flow complexity, inflow concentration) did show complete accordance, and evaluation of quantitative hemodynamic parameters (r(average/maximum wall shear stress diastole) = 0.92/0.88, P-average/maximum wall shear stress diastole < .001/.001; r(average/maximum wall shear stress systole) = 0.94/0.93, P-average/maximum wall shear stress systole < .001/.001; r(impingement zone) = 0.96, P-impingement zone < .001; r(low-stress zone) = 1.00, Plow-stress zone = .01; r(pressure diastole) = 0.84, P-pressure diastole = .002; r(pressure systole) = 0.9, P-pressure systole < .001; r(flow velocity diastole) = 0.95, P-flow velocity diastole < .001; r(flow velocity systole) = 0.93, P-flow velocity systole < .001) did show nearly complete accordance between 4D- and 3D-DSA. CONCLUSIONS: Despite a different injection protocol, 4D-DSA is a reliable basis for computational fluid dynamics analysis of the intracranial vasculature and provides equivalent visualization of aneurysm geometry compared with 3D-DSA.