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.
MR angiography uses MRI technology and, in some cases, does not require the use of contrast. 1  CTA is a type of exam that uses CT technology to look at blood vessels. 2  A CT scanner rotates to take X-ray images from different angles all around your body. 3  CT provides clearer, more detailed pictures than traditional X-rays. CTA is typically used to examine blood vessels in the brain, neck, abdomen and chest. We use the latest technology, including 64-slice CT scanners. A radiologist with special training in CT and the vascular system will interpret your exam.