CT perfusion for simultaneous imaging of lung ventilation and perfusion (VQ)

We created a CT perfusion (CTP) method to measure lung ventilation and blood flow simultaneously, improving upon traditional V/Q scans. In anesthetized pigs (n=8), CTP scans captured density changes reflecting both air movement (ventilation) and blood flow (perfusion). Using advanced math (Johnson-Wilson-Lee model), we separated these signals: blood flow was calculated by tracking contrast dye movement, while ventilation was derived from residual air volume changes during breathing cycles. The technique generated complete 3D maps of both functions. When analyzing lung regions vertically, we observed expected gravity-dependent patterns (more blood flow/air in lower zones), matching known physiology. Breathing rates measured by our method precisely matched the ventilator settings, confirming accuracy. This single-scan approach could eventually replace separate ventilation/perfusion tests in clinics. Future work will compare results against gold-standard xenon CT and PET scans to validate the method for human use.