Functional methods of clinical medical images

X-ray examination of bone joints mainly uses photos, not fluoroscopy. It is only used to find foreign bodies, locate gunshot wounds and repair traumatic fractures and dislocations.

Attention should be paid to the following points when taking pictures: ① Any part, including the long bones of limbs, joints and spine, should be taken in a positive lateral position. Some parts should also use oblique position, tangent position and axial position. ② Surrounding soft tissues should be included. Photographs of long bones of limbs should include an adjacent joint. For example, when taking spinal photography, the lumbar vertebrae should include the lower thoracic vertebrae for counting; ③ Bilateral symmetrical bone and joint, if the lesion is on one side and the symptoms and signs are light, or the upper side of X-ray film has changed, but it is not obvious enough, the contralateral side should be photographed and compared under the same technical conditions. (1) Tomography In the part where the structure of bone and joint itself is complex or overlaps with other structures, tomography can make the structure display clearly. It can also show the focus of osteopathy more clearly.

(2) Zoom-in photography uses a micro-focus X-ray tube. Through direct magnification of X-ray images, we can observe the fine structure and subtle changes of bones. It is usually used to examine local trabecular structures and small joints. (1) arthrography The articular space is composed of articular cartilage and a small amount of synovial fluid, and there is an anatomical articular space between the opposite articular cartilage, which is obviously compared with the bones that make them up. Therefore, the narrowing and widening of joint space, the destruction and hardening of bony articular surface can be clearly shown on plain films. The cartilage disc, joint capsule, synovium and ligament in the joint are all soft tissues with the same density, and there is no contrast on plain film. These soft tissue injuries and lesions need to be observed by injecting contrast agent into the joint cavity to form artificial radiography, that is, arthrography.

Arthrography usually uses gas as contrast agent or injects organic iodine solution into joint cavity. It is also possible to inject organic iodine solution and gas at the same time for double comparison.

(2) Angiography Angiography is mostly used for limb arteries. It is mainly used for the diagnosis of vascular diseases and the differentiation of benign and malignant tumors. For the latter, the diagnosis was made according to the vascular morphological changes of the tumor, the blood flow of the tumor and the displacement of the adjacent blood vessels.