An Enhanced Patient-Specific Computer Model Using an Iterative Multi-Staged Algorithm

Background: A previously introduced patient-specific computer model was applied to predict outcomes of the balloon occlusion test (BOT). The goal of this work was to propose an enhanced patient-specific computer model using a new iterative multi-staged algorithm. Method: This work presents an enhanced patient-specific computer model which converts several more terminals from generic, to patient-specific, resistances and also makes the aortic pressure and the stiffness coefficient patient-specific. A new iterative multi-staged algorithm is proposed to determine the terminal resistances, the aortic pressure, and the stiffness coefficient using vessel sizes and vessel flows measured by quantitative magnetic resonance angiography (qMRA) and cuff pressure. The predictions of the BOT were also evaluated for the validation of the proposed model. Results: The predictions from the proposed model were accurate in comparison with the clinical outcomes of the two BOTs. The computed stiffness coefficients were consistent with the ages of the two patients. The correlation coefficients between the flow measurements and the computed flows using the proposed computer model at baseline for the two patients were 0.9861 and 0.9995, respectively. The computed aortic pressures were also comparable in waveform shape with the actual aortic pressure measurements obtained during the BOT using a catheter-transducer. Conclusion: The present study makes the computer model more patient-specific with a new algorithm using non-invasive data from qMRA and cuff pressure. The six more sectors have made the terminal resistances more patient-specific. The patient-specific aortic pressure has made the forcing function patient-specific. And the stiffness coefficient has made the compliance patient-specific. J Neurol Res. 2017;7(3):25-38 doi: https://doi.org/10.14740/jnr435w