antigen specific immunity attributable to the production of antibody and of specific immune T lymphocytes (responsible for cell-mediated immunity), following exposure to an antigen, or passive transfer of antibody or immune lymphoid cells (adoptive immunity).
Types of X-rays and Scans. MRA (Magnetic Resonance Angiography) MRAâa type of magnetic resonance imaging (MRI) study that is obtained with the same scanning machineâuses a strong magnetic field combined with radiofrequency waves to create highly detailed images of blood vessels in the body. (MRA is most often used to examine vessels in the brain, neck, kidneys, and legs.) The resulting scans, which provide information about blood flow and the condition of blood vessel walls, may then be saved on a computer or on film and examined for abnormalities.
A CT angiography (CTA) scan is a special kind of CT exam that focuses particularly on the blood vessels, using a contrast material to make them show up clearly in the images. Common uses. CTA is used to examine blood vessels in areas including the brain, neck, chest and abdomen. Conditions that the exam can reveal include aneurysms and narrowing of the arteries. Safety. CT examinations improve health care and are an essential part of diagnosis and treatment planning.