In terms of radiation exposure, which imaging technique usually requires the highest dose to the patient?

The imaging technique that typically requires the highest dose of radiation for the patient is the CT scan. This is primarily due to the higher levels of ionizing radiation used in computed tomography compared to other imaging modalities. In a CT scan, multiple X-ray images are taken from various angles and then processed to create cross-sectional images of the body, which necessitates a greater cumulative dose.

In contrast, standard X-rays involve a single exposure and generally use lower radiation levels. MRI and ultrasound do not utilize ionizing radiation at all, making them safer alternatives in terms of radiation exposure. MRI uses magnetic fields and radio waves, while ultrasound employs sound waves, both of which do not pose the same risks associated with radiation exposure as CT scans and X-rays. Thus, in the context of radiation dose to patients, the CT scan stands out as requiring the highest amount.