Magnetic resonance imaging, or MRI, and ultrasounds are effective alternatives to a CAT scan, depending on the circumstances, according to DrGreene.com. MRIs are usually preferable to CAT scans for imaging the head, excluding cases of trauma because MRIs require a minimum of 45 minutes to complete.
DrGreene.com advocates the use of MRIs instead of CAT scans for assessing most musculoskeletal issues. MRIs are also an effective alternative to CAT scans for imaging the spine. Ultrasounds are equal in efficacy to CAT scans for capturing images of the abdomen or pelvis. However, as MRI technology improves, DrGreene.com suggests that MRIs might become the best option for imaging these regions of the body.