To reduce pixel size while keeping the field of view constant, you should:

To reduce pixel size while keeping the field of view constant, you should:

• A. Increase Matrix Size
• B. Increase FOV
• C. Increase mA
• D. Increase kVp

Answer: (A)

Pixel size is determined by how the field of view is sampled by the detector’s matrix. With the field of view held constant, the pixel size equals the field of view divided by the matrix size. Therefore, to reduce pixel size you need to increase the matrix size. If you go from a 256×256 matrix to a 512×512 matrix with the same FOV, each pixel covers roughly half the area, improving spatial sampling and potentially sharpness. Exposure factors like mA or kVp affect brightness and contrast, not how finely the image is sampled. Changing the field of view would change how much anatomy is imaged, not the pixel dimensions. So the correct approach is to increase the matrix size.

Pixel size is determined by how the field of view is sampled by the detector’s matrix. With the field of view held constant, the pixel size equals the field of view divided by the matrix size. Therefore, to reduce pixel size you need to increase the matrix size. If you go from a 256×256 matrix to a 512×512 matrix with the same FOV, each pixel covers roughly half the area, improving spatial sampling and potentially sharpness. Exposure factors like mA or kVp affect brightness and contrast, not how finely the image is sampled. Changing the field of view would change how much anatomy is imaged, not the pixel dimensions. So the correct approach is to increase the matrix size.