Radiation Dose Measurement in Head and Neck and Chest CT Examinations Using Multi-Detector CT

Area of Science:

• Medical Physics
• Radiology
• Radiation Dosimetry

Background:

• Computed tomography (CT) utilization is increasing, raising concerns about associated cancer risks.
• Accurate assessment of radiation doses in CT examinations is critical for patient safety.
• This study addresses the need for precise radiation dose evaluation in CT procedures.

Purpose of the Study:

• To evaluate mean radiation doses in the thyroid, lungs, and heart using multi-slice CT.
• To compare radiation dose measurements obtained from thermo-luminescent dosimeters (TLDs) and dose monitoring software.
• To assess the accuracy of different dosimetry methods in CT examinations.

Main Methods:

• Thirty patients underwent head, neck, and chest CT scans.
• Thermo-luminescent dosimeters (TLDs) were used to measure skin dose to the thyroid, lungs, and heart.
• Mean absorbed doses, effective doses, and CTDIvol were collected and compared.

Main Results:

• The thyroid received the highest mean absorbed dose (34.95 mGy) during head and neck CT protocols.
• TLD measurements indicated significantly higher radiation doses compared to CTDIvol, particularly for the thyroid during head and neck exams (~358.83% difference).
• Higher correction counts (CC) were observed with TLDs in head and neck scans (mean CC: 1435.05) versus chest scans (mean CC: 851.29).

Conclusions:

• Dose monitoring software, CTDIvol, and experimental measurements are crucial for evaluating CT imaging protocols.
• TLD-based dosimetry provides more accurate radiation dose values than CTDIvol.
• Implementing robust dose monitoring is essential for optimizing CT imaging practices and minimizing patient radiation exposure.