1 . CT scans use X-rays to produce images inside the body while MRI (magnetic resonance imaging) uses powerful magnetic fields and radio pulses to produce detailed images of organs and other internal organs. 2 . CT scans use radiation (X-ray), and MRI scans do not. 3 . MRIs provide a greater level of detail about internal organs (soft tissues) than CT scans, such as the brain, skeletal system, reproductive system, and other organ systems. 4 . CT scans are fast, painless, and non-invasive. 5 . MRI scans are non-invasive, but they are noisy, time-consuming, and can cause claustrophobia (anxiety due to being in a confined space).