COMPARISON OF CBCT AND CT IN TERMS OF DOSE VALUE OF ORGANS AT RISK IN PARANASAL SINUS IMAGING

Area of Science:

• Radiological Physics
• Medical Imaging Technology
• Radiation Dosimetry

Background:

• Radiation dose to organs at risk (OARs) is a critical consideration in medical imaging.
• Computed tomography (CT) and cone beam computed tomography (CBCT) are widely used for head and neck imaging, but their dose profiles differ.
• Understanding dose distribution in OARs surrounding the paranasal sinuses is essential for patient safety.

Purpose of the Study:

• To compare the irradiated dose to OARs around the paranasal sinuses between CBCT and multi-spiral CT.
• To evaluate the influence of organ position relative to the imaging field on radiation dose.
• To determine the optimal imaging modality for minimizing radiation exposure in paranasal sinus examinations.

Main Methods:

• Utilized an Alderson-Rando phantom with thermoluminescence dosemeters for irradiation.
• Performed irradiations using three routine CBCT protocols and one multi-spiral CT protocol.
• Assessed radiation doses for organs both inside and outside the imaging field for each modality.

Main Results:

• Multi-spiral CT generally resulted in higher measured doses for most investigated organs compared to CBCT.
• The low-resolution mode of CBCT exhibited the lowest radiation dose.
• No significant differences in dose were found for out-of-field organs across CBCT modes, but significant differences existed between CT and CBCT for all OARs.

Conclusions:

• CBCT is recommended over multi-spiral CT for paranasal sinus imaging due to its significantly lower radiation dose.
• Comparable image quality between the two modalities supports the use of CBCT for dose reduction.
• Further investigation into dose optimization strategies within CBCT protocols is warranted.