The difference between CT and color ultrasound: First of all, these are two different examination methods. CT is an image formed by scanning, imaging and processing of rays through computer, and ultrasound is an imaging principle using acoustic image waves, so the imaging principles of the two are different. Secondly, the scope of application is also different. CT has a wider scope and can basically be applied to all organs of the body, while color ultrasound cannot examine gas-containing organs and bones and joints. In view of the differences between them, it is necessary to choose different examination methods to carry out in clinical practice according to the specific conditions of patients, such as lung examination, bone and joint examination, etc. CT should be chosen to carry out the examination.