Radiologic technologists use radiation (x-rays) to produce black-and-white images of anatomy. X-rays may be used to detect bone fractures, find foreign objects in the body, and demonstrate the relationship between bone and soft tissue.
Nuclear med techs administer trace amounts of radiopharmaceuticals to a patient to obtain functional information about organs, tissues and bone. The technologist then uses a special camera to detect gamma rays emitted by the radiopharmaceuticals and create an image of the body part under study.
Nuclear medicine pays a lot more. RTs are on the low end of the totem pole.
You can find more information here: https://www.asrt.org/content/aboutthepro…http://www.jrcnmt.org/http://www.snm.org/