Effect of tube current modulation for dose estimation using a simulation tool on body CT examination

Area of Science:

• Medical Imaging
• Radiological Physics
• Radiation Dosimetry

Background:

• Accurate dose estimation in computed tomography (CT) is crucial for patient safety.
• Tube current modulation (TCM) is a technique used to optimize radiation dose in CT examinations.
• Understanding the impact of TCM on organ dose is essential for precise risk assessment.

Purpose of the Study:

• To evaluate the impact of tube current modulation on dose estimation in body CT.
• To compare longitudinal variations in tube current values between iterative reconstruction (IR) and filtered back-projection (FBP) algorithms.
• To assess the differences in organ and effective doses using average versus modulated tube current values.

Main Methods:

• Simulation tool used for dose estimation in 100 body CT patients.
• Longitudinal tube current values recorded around 10 organ regions.
• Organ and effective doses simulated using average and modulated tube current values.

Main Results:

• Organ doses for bladder (20% higher) and breast (25% lower) showed significant differences with modulated TCM compared to average values.
• Differences in estimated effective doses were minimal (mean 0.7 mSv).
• Longitudinal tube current variations were comparable between IR and FBP algorithms.

Conclusions:

• Tube current modulation significantly impacts specific organ dose estimations in body CT.
• The choice between IR and FBP algorithms has minimal effect on longitudinal tube current variations.
• Accurate dose assessment requires considering TCM effects on individual organs.