Operator Dose Measurements and Image Quality Assessment in Computed Tomography Fluoroscopy Using Bismuth Sheet

Area of Science:

• Medical Imaging
• Radiological Physics

Background:

• Computed tomography fluoroscopy (CTF) involves radiation exposure to operators.
• Dose reduction strategies are crucial for improving safety in interventional radiology.

Purpose of the Study:

• To evaluate the effectiveness of bismuth sheets in reducing operator radiation dose during CTF.
• To assess the impact of bismuth sheets on CTF image quality, including contrast and contrast-to-noise ratio (CNR).

Main Methods:

• 1-mm thick bismuth sheets were utilized to reduce frontal X-ray exposure.
• Operator dose rates were measured using a torso phantom in patient positions (center and off-center) during CTF.
• Image quality was assessed using a phantom simulating liver parenchyma and low attenuation lesions, comparing contrast and CNR with and without bismuth sheets.

Main Results:

• Bismuth sheets significantly reduced operator dose rates, with exposure reductions of 42.3% at the center and 34.5% off-center.
• No significant degradation in image contrast or CNR was observed.
• CT values of liver parenchyma and low attenuation lesions increased with bismuth sheets.

Conclusions:

• Bismuth sheets are an effective method for reducing operator radiation exposure during CTF.
• The use of bismuth sheets does not compromise the diagnostic image quality of CTF examinations.