bone, joint, and muscle disorders
Tests for Musculoskeletal Disorders
Imaging Tests
Various types of imaging tests can help doctors diagnose musculoskeletal disorders. X-Rays are typically done first. They are most valuable for detecting abnormalities in bone and are taken to evaluate painful, deformed, or suspected abnormal areas of bone. Often, x-rays can help to diagnose To help determine whether the joint has been damaged by injury, a doctor may use an ordinary (non-stress) x-ray or one taken with the joint under stress caused by certain positions (stress x-ray). is an x-ray procedure in which a radiopaque dye is injected into a joint space to outline the structures, such as ligaments inside the joint. Arthrography can be used to view torn ligaments and fragmented cartilage in the joint. However, Computed tomography (CT) and magnetic resonance imaging (MRI) (MRI) is now generally used in preference to arthrography. Bone scanning (a type of Radionuclide Scanning ) is an imaging procedure that is occasionally used to diagnose a fracture, particularly if other tests, such as plain x-rays and computed tomography (CT) or magnetic resonance imaging (MRI), do not reveal the fracture. Bone scanning involves use of a radioactive substance (technetium-99m–labeled pyrophosphate) that is absorbed by any healing bone. The procedure can also be done when a bone infection or a tumor that has spread from a cancer elsewhere in the body is suspected. Although a bone scan may show a problem in the bone, it may not show whether the problem is a fracture, tumor, or infection. The radioactive substance is given by vein (intravenously) and is detected by a bone-scanning device, which creates an image of the bone that can be viewed on a computer screen. Computed Tomography (CT) (CT) and MRI is especially valuable for imaging muscles, ligaments, and tendons. MRI can be used if the cause of pain is thought to be a severe soft-tissue problem (for example, rupture of a major ligament or tendon or damage to important structures inside the knee joint). CT is useful if MRI is not recommended or unavailable. CT exposes people to ionizing radiation (see Risks of Radiation in Medical Imaging ). CT best images bone. However, MRI is better than CT for imaging some bone abnormalities, such as small fractures of the hip and pelvis. The amount of time a person spends undergoing CT is much less than for MRI. MRI is more expensive than CT and, with the exception of when the open-sided units are used, many people feel claustrophobic inside the MRI unit. The most accurate way to evaluate bone density, which is necessary when screening for or diagnosing osteopenia or Bone density testing , is with dual-energy x-ray absorptiometry (DXA). DXA is also used to predict a person's risk of fracture and can be useful for monitoring the response to treatment as well. This test is quick and painless and involves very little radiation. In this test, x-rays are used to examine bone density at the lower spine, hip, wrist, or entire body. Measurements of bone density are very accurate at these sites. When screening people for Bone density testing , doctors prefer taking measurements of the lower spine and hip. To help differentiate osteoporosis (the most common cause of an abnormal DXA scan result) from other bone disorders, doctors may need to consider the person's symptoms, medical conditions, drug use, and certain blood or urine test results as well as the DXA results. Ultrasonography is being used more and more frequently to identify abnormalities and inflammation in and around joints and tears or inflammation of tendons. Ultrasonography is also used as a guide when a needle needs to be put into a joint (for example, to inject drugs or to remove joint fluid). As an alternative to 