Denville Medical - General Medicine Terms

NCV
A nerve conduction velocity test (NCV) is an electrical test that is used to determine the adequacy of the conduction of the nerve impulse. This is used to detect nerve injury. In this test, the nerve is electrically stimulated while a second electrode detects the electrical impulse 'down stream' from the first. This is usually done with surface patch electrodes (they are similar to those used for an electrocardiogram) that are placed on the skin over the nerve at various locations. One electrode stimulates the nerve with a very mild electrical impulse. The resulting electrical activity is recorded by the other electrodes. The distance between electrodes and the time it takes for electrical impulses to travel between electrodes are used to calculate the speed of impulse transmission (nerve conduction velocity). A decreased speed of transmission indicates nerve disease. A nerve conduction velocity test is often done at the same time as an electromyogram (EMG) in order to exclude or detect muscle conditions.

EMG
An electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction. Nerve conduction studies measure how well and how fast the nerves can send electrical signals. Nerves control the muscles in the body by electrical signals (impulses), and these impulses make the muscles react in specific ways. Nerve and muscle disorders cause the muscles to react in abnormal ways. Measuring the electrical activity in muscles and nerves can help find diseases that damage muscle tissue (such as muscular dystrophy) or nerves (such as amyotrophic lateral sclerosis or peripheral neuropathies). EMG and nerve conduction studies are often done together to give more complete information.

X-Ray
An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging. A bone x-ray makes images of any bone in the body, including the hand, wrist, arm, foot, ankle, knee, leg or spine. A bone x-ray is used to determine whether a bone has been fractured or if a joint is dislocated, ensure that a fracture has been properly aligned and stabilized for healing following treatment, determine whether there is a build up of fluid in the joint or around a bone, guide orthopedic surgery, such as spinal repair, joint replacement and fracture reductions, evaluate injury or damage from conditions such as infection, arthritis, abnormal bone growths or other bone diseases, such as osteoporosis, to assist in the detection and diagnosis of cancer, to locate foreign objects, and evaluate changes in bones and joints.

EKG
An electrocardiogram, also called an EKG, is a simple test that detects and records the electrical activity of the heart. It is used to detect and locate the source of heart problems. Electrical signals in the heart trigger heartbeats. These signals start at the top of the heart in an area called the right atrium. The electrical signals travel from the top of the heart to the bottom. They cause the heart muscle to contract as they travel through the heart. As the heart contracts, it pumps blood out to the rest of the body. An EKG shows how fast the heart is beating. It shows the heart’s rhythm (steady or irregular) and where in the body the heartbeat is being recorded. It also records the strength and timing of the electrical signals as they pass through each part of the heart. An EKG is sometimes called a 12-lead EKG because the electrical activity of the heart is most often recorded from 12 different places on the body at the same time.

Spirometry-Respiratory Function
Spirometry is the most basic and frequently performed test of pulmonary (lung) function. A device called a spirometer is used to measure how much air the lungs can hold and how well the respiratory system is able to move air into and out of the lungs. Because spirometry is based on a maximal forced exhalation, the accuracy of its results is highly dependent on the patient's understanding, cooperation, and best efforts. This test is used to determine the cause of shortness of breath, to rule out any kind of obstructive disease that blocks breathing, or restrictive disease that limits the expansion and capacity of the lungs. Spirometry is most often used to diagnose and monitor lung problems, such as chronic bronchitis, emphysema, pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), or asthma. Spirometry is also used to monitor how well medications for respiratory problems are working and to evaluate breathing capability prior to surgery.