Radiation dose reduction in thoracic and abdomen-pelvic CT using tube current modulation: a phantom study

Area of Science:

• Medical Imaging
• Radiological Physics
• Radiation Dosimetry

Background:

• Computed Tomography (CT) scans deliver significant radiation doses.
• Optimizing radiation dose while maintaining image quality is crucial in CT imaging.
• Tube current modulation (TCM) is a technique used to adjust radiation output during CT scans.

Purpose of the Study:

• To compare radiation doses in thoracic and abdomen-pelvic CT scans.
• To evaluate the effectiveness of tube current modulation (TCM) in reducing radiation dose.
• To assess dose reduction using effective dose (ED) and size-specific dose estimation (SSDE).

Main Methods:

• A phantom study was conducted to simulate thoracic and abdomen-pelvic CT scans.
• Radiation doses were measured with and without the use of tube current modulation (TCM).
• Absorbed doses to radiosensitive organs were measured using thermoluminescence dosimeter-100 (TLD-100).
• Effective dose (ED) and size-specific dose estimation (SSDE) were calculated.

Main Results:

• TCM significantly reduced both ED and SSDE in thoracic and abdomen-pelvic CT scans compared to protocols without TCM.
• With TCM, ED for thoracic CT was 6.50 ± 0.29 mSv and for abdomen-pelvic CT was 6.01 ± 0.20 mSv.
• Without TCM, ED increased to 20.07 ± 0.24 mSv (thoracic) and 17.30 ± 0.41 mSv (abdomen-pelvic).
• Highest absorbed doses were observed in the breast (thoracic CT) and skin (abdomen-pelvic CT), with substantial reductions when TCM was used.

Conclusions:

• Tube current modulation (TCM) is highly effective in reducing radiation dose during thoracic and abdomen-pelvic CT.
• The use of TCM leads to significant dose savings, particularly for radiosensitive organs.
• TCM is strongly recommended for routine implementation in clinical practice for thoracic and abdomen-pelvic CT examinations.