Dosimetric Study of Custom-made Pelvic Perspex Phantom using Single-Energy Mode (SECT) and Dual-Energy Mode (DECT) Computed Tomography

ABSTRACT

@#Introduction: A custom-made Perspex male pelvic phantom was developed to measure and to compare absorbed, surface and effective doses obtained from Single-Energy and Dual-Energy Computed Tomography (SECT & DECT). Methods: A customised Perspex pelvic phantom that mimicked male Asian reference size was scanned with SECT mode at 80 kV, 100 kV, 120 kV and 140 kV. In addition, the fabricated phantom was also scanned with DECT mode at 80/140 kV. Thermoluminescence dosimeters (TLD) were used to measure the charges and doses obtained from the TLD calibration curve. The absorbed dose, surface dose and effective dose obtained from SECT and DECT were measured and compared between these two modes. Results: The DECT showed 55.9 % dose reduction compared to SECT at 140 kV tube voltage. It shows that DECT can be used with radiation dose sparing, and it is in good agreement with routine CTDI phantom study. The effective dose of DECT of the abdominal imaging was within the acceptable effective dose limit of AAPM Report No. 96. This study also found that the surface dose was lower than values reported in previous studies for both modes. Conclusion: The fabricated Perspex phantom shows a great potential to be considered as an alternative phantom for the commercially existing phantom in CT dosimetry application.