Validation of computational fluid dynamics in CT-based airway models with SPECT/CT

Area of Science:

• Medical Imaging
• Computational Fluid Dynamics
• Respiratory Medicine

Background:

• Interpatient variability in airway geometry significantly impacts respiratory function.
• Accurate assessment of airflow distribution is crucial for understanding respiratory diseases.
• Functional imaging techniques like SPECT/CT offer insights into ventilation patterns.

Purpose of the Study:

• To compare airflow distribution results from numerical flow simulations with those from SPECT/CT.
• To emphasize the necessity of correct boundary conditions in numerical methods for CFD.
• To account for significant interpatient variability in airway geometry.

Main Methods:

• Six patients with mild asthma underwent CT and SPECT/CT scans.
• CT data were utilized for segmentation and computational fluid dynamics (CFD) simulations.
• Airflow distribution was compared between SPECT/CT, CT-based lobar expansion, and CFD simulations.

Main Results:

• CFD and CT demonstrated good agreement with SPECT/CT for airflow distribution (<3% difference).
• Both SPECT/CT and CFD successfully detected heterogeneity in ventilation patterns.
• Hot spot detection was consistent across SPECT/CT and CFD methods.

Conclusions:

• Patient-specific CFD simulations with appropriate boundary conditions provide information comparable to functional imaging (SPECT/CT).
• Numerical simulations are valuable tools for understanding airflow dynamics in diverse airway geometries.
• This validates the use of CFD as a complementary tool to SPECT/CT in respiratory research.