Patient-specific dose estimation considering subject thickness with an RGB-D camera: A phantom study

Area of Science:

• Medical Imaging
• Radiological Physics
• Biomedical Engineering

Background:

• Patient-specific radiation dose management is crucial for balancing diagnostic image quality and radiation safety.
• Current methods for dose estimation often lack accuracy for patients with non-standard body sizes.
• Non-invasive measurement of patient thickness is vital for tailoring radiation dose, specifically entrance surface dose (ESD).

Purpose of the Study:

• To evaluate the feasibility and accuracy of using an RGB-D camera for real-time patient thickness measurement.
• To assess the capability of RGB-D camera measurements for patient-specific ESD estimation in abdominal radiography.

Main Methods:

• An abdominal phantom with varying thicknesses (20-40 cm) was used.
• An RGB-D camera was mounted on a radiography unit to capture depth data at multiple positions.
• Thickness measurements were compared to caliper measurements, and ESD was calculated using both methods.

Main Results:

• RGB-D camera measurements showed high accuracy, with deviations up to ±0.3 cm at the detector center.
• Off-center measurements had slightly larger errors (up to ±1.2 cm), with minimal positional variability.
• ESD estimates using RGB-D data demonstrated minimal differences (within ±0.7%) compared to caliper-based estimates.

Conclusions:

• RGB-D camera-based thickness measurement is a feasible and accurate technique for non-invasive, patient-specific ESD estimation.
• This technology supports pre-imaging dose assessment and personalized dose control in radiographic practices.
• The method has the potential to improve safety and consistency in abdominal radiography.