Final answer:
Digitally subtracted images may require remaking due to noise, motion artifacts, and underexposure, with retaking or digital manipulation needed for correct diagnosis.
Step-by-step explanation:
Digitally subtracted images may need to be masked due to noise artifacts, motion artifacts, and underexposure, which means the correct answer is all of the above. Noise artifacts can emerge from electronic interference or inherent fluctuations in the imaging system, while motion artifacts are the result of the patient moving during image acquisition. As for underexposure, it occurs when too little light reaches the camera's sensor, leading to dark, indistinguishable images. To correct these images, retaking or digital manipulation might be necessary, to ensure the resulting images convey accurate and useful diagnostic information without misleading distortions.