Glossary

Anti-nuclear antibody

Absolute Neutrophil Count – The number of neutrophils or polymorphonuclear white blood cells (AKA PMN’s, polys, granulocytes, segmented neutrophils or segs) present in the blood. These are a type of white blood cell that fights against infection.

The picture of a blood vessel. In typical usage it refers to a radiographic image of a blood vessel that has been filled with a contrast element that is radiopague or radiodense on x-ray imaging.

Anterior-posterior.  This abbreviation typically is used to define a direction, such as a direction of a x-ray beam in an image (e.g., AP chest x-ray is an image where the patient stands facing a xray beam source with the film being placed behind them.

Atrial Septal Defect. A hole in the septum or wall that separates the right from left atria or upper chambers of the heart.

Acute ischemic stroke.  A stroke due to blockage of blood supply to an region of the body such as a part of the brain.

Atypical teratoid rhabdoid tumor – A rare, fast growing tumor arising in the central nervous system of young children. Roughly 50% will occur in the brainstem or cerebellum.

A group of movement disorders that affect muscle control resulting in poor coordination,  balance and altered speech pattern.

A specific type of involuntary, abnormal muscle contraction characterized by a slow, complicated, writhing pattern 0f movement.

Advanced Trauma Life Support.  Guidelines developed by the Committee on Trauma of the American College of Surgeons for managing trauma in the acute setting.