Development of phantom for current modulation quality assurance test on computed tomography.

Area of Science:

• Medical Physics
• Radiological Technology
• Diagnostic Imaging

Background:

• Automatic tube current modulation (ATCM) is crucial for minimizing patient radiation dose in computed tomography (CT).
• Quality control (QC) for ATCM ensures CT systems accurately adapt radiation output to varying object sizes.
• Existing QC methods may not adequately assess ATCM performance across different attenuation levels.

Purpose of the Study:

• To develop and validate a dedicated phantom for assessing the performance of ATCM in CT scanners.
• To evaluate the capability of CT systems to modulate tube current in response to changes in object attenuation using the developed phantom.
• To ensure compliance with national and international quality assurance recommendations for CT examinations.

Main Methods:

• A novel phantom was constructed from high-density polyethylene, featuring a cylindrical shape with three distinct sizes.
• The phantom was utilized to conduct ATCM quality control tests on two different CT scanner models (Toshiba and Philips).
• Measurements focused on evaluating the CT system's adaptation of tube current as a function of the phantom's size and attenuation.

Main Results:

• The study demonstrated a clear correlation between discrete changes in phantom size and corresponding adjustments in tube current.
• CT scanners exhibited appropriate adaptation of tube current when presented with distinct shifts in object attenuation.
• The results confirm the CT system's ability to modulate radiation output effectively based on object characteristics.

Conclusions:

• The developed high-density polyethylene phantom is a suitable tool for performing ATCM quality control tests in CT.
• This phantom facilitates the verification of CT scanner performance in adapting radiation dose according to object size.
• The phantom supports adherence to quality assurance standards, enhancing patient safety during CT scans.