A phantom approach to find the optimal technical parameters for plain chest radiography

Area of Science:

• Medical Physics
• Radiology
• Diagnostic Imaging

Background:

• Optimizing diagnostic imaging requires balancing patient radiation dose with image quality.
• Selecting appropriate X-ray beam filtration, tube potential, and antiscatter devices is crucial for this balance.

Purpose of the Study:

• To determine optimal filtration, tube potential, and antiscatter techniques for chest radiography.
• To minimize patient dose while maximizing image quality using phantom measurements.

Main Methods:

• Utilized a quasi-anthropomorphic chest phantom exposed to 18 beam qualities and 3 antiscatter devices.
• Measured entrance surface dose, organ doses, and effective dose.
• Assessed image quality using objective (contrast index, scatter fraction) and subjective indexes.

Main Results:

• Optimal technique with a 7:1 antiscatter grid: 0.1 mm Cu + 1 mm Al filtration at 100 kVp.
• Using a 25 cm air gap allowed 120 kVp, reducing entrance surface dose by over 50% compared to the grid technique.
• The air gap technique resulted in an entrance surface dose of 0.075 mGy, well below the European reference level.

Conclusions:

• A phantom-based method combining objective and subjective assessments is effective for dose-image quality optimization.
• The study identified specific technique parameters (filtration, kVp, antiscatter device) for improved chest radiography.
• Reduced patient dose is achievable without compromising diagnostic image quality.