SU-D-217BCD-06: Evaluation of Effective Dose during Neuro 3-D Imaging Using a C-Arm Cone-Beam CT System

Area of Science:

• Medical Physics
• Radiological Imaging
• Radiation Dosimetry

Background:

• Neuro 3D-imaging protocols are increasingly used in clinical practice.
• Accurate estimation of patient organ doses and effective dose (ED) is crucial for radiation protection.
• Cone-beam CT (CBCT) systems are common in neuro-interventional procedures.

Purpose of the Study:

• To estimate organ doses and effective dose (ED) for patients undergoing neuro 3D-imaging.
• To investigate the impact of beam collimation on ED in these procedures.
• To derive protocol-specific dose area product (DAP)-to-ED conversion factors.

Main Methods:

• Organ doses were measured using MOSFET detectors in an anthropomorphic phantom for seven neuro imaging protocols on a CBCT system.
• Measurements were conducted with both uncollimated (entire head FOV) and collimated beams.
• Effective dose (ED) was calculated using ICRP 103 tissue weighting factors, and dose area product (DAP) was recorded.

Main Results:

• For uncollimated protocols, ED ranged from 0.16 to 1.6 mSv, with DAP-to-ED conversion factors from 0.037 to 0.17 mSv/Gy/cm².
• Beam collimation reduced ED by approximately 50% and DAP-to-ED conversion factors by about 30%.
• These findings highlight the dosimetric impact of beam collimation in neuro 3D-imaging.

Conclusions:

• Effective dose (ED) was successfully measured for standard adult neuro imaging protocols using a 3D rotational angiography system.
• The study provides a straightforward method for estimating ED from console-displayed DAP values in C-arm CBCT.
• The results are valuable for optimizing radiation protection in neuro-interventional radiology.