Recently, image-based computational fluid dynamic simulations (CFD) have been proposed to investigate the local
hemodynamics inside human cerebral aneurysms. It is suggested that the knowledge of the computed three-dimensional
flow fields can be used to assist clinical risk assessment and treatment decision making.
However, the reliability of CFD for accurately representing the human cerebral blood flow is difficult to assess due to
the impossibility of ground truth measurements. A recently proposed virtual angiography method has been used to
indirectly validate CFD results by comparing virtually constructed and clinically acquired angiograms. However, the
validations are not yet comprehensive as they lack either from patient-specific boundary conditions (BCs) required for
CFD simulations or from quantitative comparison methods.
In this work, a simulation pipeline is built up including image-based geometry reconstruction, CFD simulations
solving the dynamics of blood flow and contrast agent (CA), and virtual angiogram generation. In contrast to previous
studies, the patient-specific blood flow rates obtained by transcranial color coded Doppler (TCCD) ultrasound are used to
impose CFD BCs. Quantitative measures are defined to thoroughly evaluate the correspondence between the clinically
acquired and virtually constructed angiograms, and thus, the reliability of CFD simulations. Exemplarily, two patient
cases are presented.
Close similarities are found in terms of spatial and temporal variations of CA distribution between acquired and
virtual angiograms. Besides, for both patient cases, discrepancies of less than 15% are found for the relative root mean
square errors (rRMSE) in time intensity curve (TIC) comparisons from selected characteristic positions.