The Technique of Angiography
According to an estimate from the Center for Disease Control and Prevention, in 2009, more than $304.6 billion was spent on heart disease. It is the leading cause of death in the United States. Most heart disease takes place when the pathways to the heart called arteries get blocked. A common medical technique to get an image of these pathways is Angiography. This article looks further at this technique.
A Portuguese physician and neurologist named Dr. Egas Moniz , developed this technique in the year 1927 using energy waves called X-rays. However, it wasn’t until 1953 that the technique became safer and an established method of medical imaging. The three main components of this technique are: The Contrast Agent, the Femoral artery/vein, Catheters.
The Role of a Contrast Agent: It is a substance which increases the visibility of the blood vessels and their hollow inner passages. Any roadblocks in the blood vessels get easily detected as a result. The contrast agent works by absorbing the X-rays sent into the target region and illuminating the veins and arteries of that region. Iodine and Barium are two such contrast agents. They are used primarily because when the X-ray interacts with them, no harmful substances are formed. In recent years, MRI and ultrasonography have been used as available options for contrast agents.
The Role of the Femoral Artery/Vein: The femoral artery/vein is a large artery/vein present in the muscles of the thigh. The arteries and veins present here are of special medical significance. Though they belong to the thigh region they have direct access to the arteries and veins of the heart organ. It is here where the contrast agent is injected into the body before the arteries and veins are illuminated with X-rays.
The Role of Catheters: In medicine, a catheter is a tube that can be inserted into veins. It provides access for surgical instruments and helps in drainage or injection of fluids into blood vessels. The catheter is placed in the femoral artery of the thigh and contrast agents like iodine or barium are injected at the sight.
Later when the arteries and veins of the heart are exposed to X-rays, the contrast agents absorb the energy and illuminate it. An image of the arteries is created by the surrounding scanning machines.