Optimisation of radiological protocols for chest imaging using computed radiography and flat-panel X-ray detectors

Area of Science:

• Radiological Physics
• Medical Imaging Technology
• Diagnostic Radiology

Background:

• Digital radiography (DR) and computed radiography (CR) have largely replaced conventional screen-film systems.
• Existing radiological protocols optimized for screen-film are often used with digital systems without critical evaluation.
• This practice may not leverage the full capabilities of digital detectors, potentially impacting image quality and patient dose.

Purpose of the Study:

• To optimize exposure settings for chest examinations using digital radiography systems.
• To evaluate the impact of optimized settings on both image quality and patient radiation dose.
• To compare the performance of direct digital radiography (DDR) and computed radiography (CR) systems.

Main Methods:

• Analysis of images acquired with DDR and CR systems using specialized software.
• Application of a four-alternative forced-choice (4AFC) method for image quality assessment.
• Evaluation of promising protocols by two senior radiologists.

Main Results:

• Digital systems' wide dynamic range and post-processing capabilities allow for lower tube potentials.
• CR systems demonstrated superior image quality and lower patient dose at reduced energies (85 kVp, 95 kVp) compared to current protocols (125 kVp).
• DDR equipment showed better image quality and lower dose requirements than CR systems.

Conclusions:

• Lowering tube potentials in chest examinations with digital equipment generally improves the image quality-to-effective dose ratio.
• Optimized protocols are crucial for maximizing the benefits of digital radiography technology.
• Further research into digital system-specific protocol optimization is warranted.