Dependence of noise on array width and depth in digital radiography

Area of Science:

• Medical Imaging
• Digital Radiography
• Image Processing

Background:

• Digital radiography is crucial for medical diagnostics.
• Understanding image noise is essential for accurate interpretation.
• Storage array size impacts image quality and noise performance.

Purpose of the Study:

• To quantify image noise levels in digital radiographs.
• To evaluate the effect of different storage array sizes on noise.
• To determine the influence of digitization levels on noise.

Main Methods:

• Measurements of image noise were performed using digital radiographs.
• Utilized storage arrays of sizes 256(2), 256(2)-zoom, 512(2), and 1024(2).
• Varied the number of bits per pixel to assess its impact on noise.

Main Results:

• Noise levels were comparable between 256(2)-zoom and 512(2) arrays.
• A 256(2) array showed 25% lower noise compared to a 512(2) array.
• A 1024(2) array exhibited 15% higher noise than a 512(2) array.
• Noise increased only when pre-digitization noise was below approximately 0.5 gray levels.

Conclusions:

• Storage array size significantly influences image noise in digital radiographs.
• The 512(2) array offers a good balance between noise and performance.
• Pre-digitization noise levels below 0.5 gray levels are critical for accurate noise assessment.