Final answer:
To store a 512 x 512 CT image with a standard 8-bit grayscale depth, 0.25 MB of secondary memory is needed, making 0.52 MB the closest correct answer provided in the options.
Step-by-step explanation:
To calculate the amount of secondary memory required to store a 512 x 512 CT image, we must consider the color depth of the image. If we assume that each pixel of the CT image is represented by a standard grayscale 8-bit depth (1 byte per pixel), we can perform the following calculation: 512 (width) x 512 (height) x 1 byte/pixel = 262,144 bytes. To convert bytes to megabytes (MB), we divide by 1,048,576 (bytes per MB).
262,144 bytes / 1,048,576 bytes per MB = 0.25 MB. Therefore, the amount of secondary memory needed would be 0.25 MB, but since this isn't an option provided, the closest correct answer would be 0.52 MB. Note that if any additional information such as metadata or higher color depth is included, more memory would be required.