If the matrix size is doubled (FOV constant), pixel size will:

If the matrix size is doubled (FOV constant), pixel size will:

• A. Decrease
• B. Increase
• C. Remain the Same
• D. Vary

Answer: (A)

When the field of view stays the same and you double the matrix size, you’re increasing the number of samples across the image while keeping the same physical area. That means each pixel covers a smaller portion of the image, so the pixel size (pixel pitch) becomes smaller. In other words, doubling the sampling density divides the same FOV into more, smaller pixels, reducing the size of each pixel. This change tends to improve spatial resolution because you’re sampling the image more finely. The other options don’t fit because increasing pixel size would require fewer samples across the same FOV, keeping the matrix smaller; keeping the pixel size the same would require no change in sampling; and changing arbitrarily (vary) isn’t consistent with a fixed FOV when the matrix is doubled.

When the field of view stays the same and you double the matrix size, you’re increasing the number of samples across the image while keeping the same physical area. That means each pixel covers a smaller portion of the image, so the pixel size (pixel pitch) becomes smaller. In other words, doubling the sampling density divides the same FOV into more, smaller pixels, reducing the size of each pixel. This change tends to improve spatial resolution because you’re sampling the image more finely. The other options don’t fit because increasing pixel size would require fewer samples across the same FOV, keeping the matrix smaller; keeping the pixel size the same would require no change in sampling; and changing arbitrarily (vary) isn’t consistent with a fixed FOV when the matrix is doubled.