Investigation of the Relationship between Body Parameters and mAs Using Non-Contact Two-Dimensional Thickness...

Area of Science:

• Radiological Physics
• Medical Imaging
• Diagnostic Radiology

Background:

• Optimizing radiation dose in digital radiography is crucial for patient safety.
• Automatic Exposure Control (AEC) systems aim to standardize image quality but require accurate parameter input.
• Understanding the relationship between patient body parameters and radiation dose is essential for AEC optimization.

Purpose of the Study:

• To investigate the correlation between patient body parameters and the radiation dose (mAs) in chest digital radiography.
• To evaluate the efficacy of a non-contact infrared sensor for measuring chest thickness.
• To identify the optimal body parameter and mathematical model for predicting mAs in AEC-controlled chest X-rays.

Main Methods:

• Utilized an anthropomorphic chest phantom to assess mAs variations with positioning under AEC.
• Enrolled 929 male subjects, recording height, weight, and Body Mass Index (BMI).
• Measured chest thickness (T) using a non-contact infrared sensor and performed chest radiography with AEC, fitting body parameters (T, BMI, T*BMI, W/H) to mAs using curve models.

Main Results:

• Phantom study revealed mAs variations up to 1.76 times between minimum and maximum.
• All human study radiographs met quality control standards with exposure indices between 100 and 212.
• The weight-to-height ratio (W/H) demonstrated the strongest correlation with mAs, with a first-order power model achieving an R-square of 0.9971.

Conclusions:

• The W/H ratio, modeled by a first-order power function, accurately predicts mAs in chest radiography using AEC.
• This predictive model can aid in optimizing radiation dose and reducing exposure in clinical settings.
• Non-contact infrared sensing provides a reliable method for chest thickness measurement in radiography.