Glossary

Human immunodeficiency virus – a slowly replicating retrovirus that attacks the human immune system causing destruction of its T-lymphoytes and macrophages. This is the caustive factor for acquired immunodeficiency syndrome (AIDS), a condition where there is a progressive failure of the host’s immune system.

hexamethyl propylene amine oxime

Head of bed – Typically used when describing how many degrees the head can be raised above the body when laying in bed.

Small, round inclusions within red blood cells that are remnants of DNA.  The spleen usually filters such cells out of circulation but when the spleen is absent or dysfunctional (as with Sickle Cell Disease) such inclusions can be seen when examining red blood cells under the microscope.

The state of overactive or exaggerated body reflexes.  Hyperactive reflexes.

Internal carotid artery

Indocyanine green.  A dye injected into the veins which can be seen to fluoresce.  The dye has a half-life of 3-4 minutes and is rapidly cleared by the liver.  It is used to visualize blood circulation within the brain.

Intracranial Hemorrhage.  Bleeding within the skull (in spaces surrounding the brain and within the brain itself).

Intracranial pressure. This refers to the pressure within the skull that is due to its fluids and tissue contents.  This pressure can be thought of as a head-wall against which the blood must flow to perfuse the brain and other contents within the skull.

International Commission on Radiology Units and Measurements – established in 1925 by the International Congress of Radiology to recommend the measurement of quantities of ionizing radiation and how it reacts with matter (in particular biologic matter).