Evaluation of different techniques for CT radiation profile width measurement

Area of Science:

• Medical Physics
• Radiological Imaging
• Radiation Measurement

Background:

• Accurate measurement of computed tomography (CT) radiation profile width is crucial for quality assurance and dose assessment.
• Conventional film-based methods and newer digital technologies require validation for this specific application.

Purpose of the Study:

• To establish and validate a procedure for measuring CT radiation profile width using a Konica Minolta computed radiography (CR) system.
• To compare the accuracy of the CR method against conventional film and GAFCHROMIC XR-QA2 film measurements.

Main Methods:

• Characterized Konica Minolta CR system exposure and processing parameters to correlate imaging plate (IP) exposure with pixel values.
• Acquired CT radiation profiles using selected CR parameters for various collimator settings (5-40 mm).
• Compared CR-derived radiation profiles with those obtained from conventional film and radiochromic film.

Main Results:

• Established optimal CR exposure and processing parameters (fixed mode, S=5, G=1.81) to avoid IP saturation.
• CR measurements for full width at half maximum (FWHM) showed agreement within ±10% of conventional film results.
• Radiochromic film measurements exhibited maximum deviations of approximately 5% compared to conventional film.

Conclusions:

• The Konica Minolta CR system provides a convenient and accurate method for measuring CT radiation profile width.
• GA মাটিতেCHROMIC XR-QA2 film also offers accurate measurements when appropriate parameters are employed.
• Both CR and radiochromic film are viable alternatives to conventional film for CT radiation profile width assessment.