Robust temporal resolution of MSCT cardiac scan by rotation-time update scheme based on analysis of patient ECG database

摘要

We have analyzed 144 ECG wave-forms that were taken during cardiac CT exams to determine in retrospect the optimized timing for updating the gantry rotation-time. A score was defined, according to the number of heart beats during X-ray on, which fulfill the temporal resolution (Tr)condition, Tr < 100mSec. The temporal resolution calculation was based on dual-cycle π/2 sector segmentation, where the data required for any image is collected during two heart cycle. The results yield a significant improvement of the Tr score with the rotation-time update method relative to using a fixed minimal rotation-time of the gantry. The analysis suggest that full heart scan with better than lOOmSec temporal resolution per slice can routinely be achieved in 128 slices MSCT scanner by performing gantry rotation-time -update after patient starts its breath hold. At these conditions the required breath-hold time is expected to be less than 15 seconds.