EFFECTIVE DOSE AND EFFECT OF DOSE MODULATION FOR LOCALIZER RADIOGRAPHS USING APPLIED AND ALTERNATIVE SETTINGS ON...

Area of Science:

• Medical Imaging
• Radiological Physics
• Radiation Dosimetry

Background:

• Thorax localizer radiographs are crucial for computed tomography (CT) procedures.
• Optimizing radiation dose from these scout images is essential for patient safety.
• Understanding dose modulation capabilities is key to reducing patient exposure.

Purpose of the Study:

• To estimate the effective dose of Toshiba/Canon thorax localizer radiographs across various parameter settings.
• To evaluate the dose modulation capabilities of these localizer radiographs.
• To compare dose reduction potential between different CT scanner models.

Main Methods:

• Acquisition of localizer radiographs using anthropomorphic chest phantoms with varying body mass indices.
• Utilized diverse kilovoltage (kV) and milliampere (mA) settings.
• Computed effective dose using Monte Carlo-based software on two CT scanner models (Aquilion Prime and One Genesis).

Main Results:

• Effective dose estimations were performed for different phantom sizes and scanner parameters.
• Dose modulation was largely unaffected across most parameter settings, except at the lowest values for the larger phantom.
• The Aquilion Prime system showed an effective dose of 0.40/0.56 mSv (male/female) with default parameters.
• Localizer radiograph dose reduction exceeding 90% was achievable without compromising modulation.
• The One Genesis system demonstrated an additional 30-50% dose reduction due to enhanced beam filtration.

Conclusions:

• Thorax localizer radiograph doses can be substantially reduced (>90%) while maintaining effective dose modulation.
• Advanced CT systems like the One Genesis offer further dose reduction benefits through improved filtration.
• Optimized parameter selection and system design are critical for minimizing radiation exposure in CT imaging.