Utility of multislice computed tomography with a 64-data acquisition system for four-dimensional volumetric analysis...

To evaluate 64-data acquisition system (DAS) MSCT (Light Speed VCT, GE) at 0.625 mm slice thickness, 0.35 s/rotation, tube 120 kV at 400 mA, ECG-gated for 4-D volumetric analysis, we used pulsating phantoms to measure end-diastolic (EDV) and end-systolic (ESV) volume and ejection fraction (EF) to assess reconstruction methods especially for higher pulsation rates.

A pulsating device (AZ-631N, Anzai Medical) with contrast material (300 mgI/dl) diluted 10x with saline was moved at 40-110 to-and-fro movements/min. ECG-gated MSCT was performed x5 per pulsation rate. The EDV and ESV were measured using workstation (Virtual Place Advance Plus, Aze).

The mean EDV and ESV were 98, 97, 97 96, 95, 94, and 101% and 145, 143, 142, 144, 145, 149, 156 and 160%, respectively, compared to the static state. EF was 80, 81, 81, 80, 79, 77, 73, and 76% at 40-110 pulsations/min, when reconstructed by the segmented method, but was improved to 82, 83, 85, and 84% at 80-110 beat/min when reconstructed by the burst method. The latter is therefore more appropriate for higher rates.

This 64-DAS MSCT can measure EDV even at high beat rates (up to 110 beats per minute) compared to the static state. Because ESV tended to be overestimated by approximately 140-160% compared with the static state, EF tended to be underestimated by approximately 73-81% compared with the static state. However, at higher beat rates of >70 beat/min, an appropriate reconstruction method (the burst method) may further improve the accuracy of EF measurement.