 |
Why is Angiograpy
Done?
X-ray angiography is performed to
specifically image and diagnose diseases of the blood vessels of the body, including the
brain and heart. Traditionally, angiography was used to diagnose pathology of these
vessels such as blockage caused by plaque build up. However in recent decades,
radiologists, cardiologists and vascular surgeons have used the x-ray angiography
procedure to guide minimally invasive surgery of the blood vessels and arteries of the
heart. In the last several years, diagnostic vascular images are often made using MR, CT
and/or ultrasound and while x-ray angiography is reserved for therapy.
Conventional x-ray angiography has a
lead role in the detection, diagnosis and treatment of heart
disease, heart attack, acute stroke and vascular disease
which can lead to stroke.
What A
Person Experiences, What to Expect During an Angiography Examination
Most conventional x-ray angiography
procedures are similar.
- Patient preparation involves removing
clothing and jewelry and wearing a patient gown. In all cases, angiography requires that intravenous contrast is administered. For
interventional or therapeutic angiography, a small incision is made in the groin or arm so
that a catheter can be inserted during the study.
- The patient is positioned on the
examination table by the technologist so that the anatomy of interest (e.g. leg artery) is
in the proper field of view between the x-ray tube and image intensifier.
 |
The doctor and technologist assure
a patient before angiography |
- The technologist and radiologist remain
at table-side during the procedure to operate the angiography system and work with the
catheters, contrast injectors and related devices. Typically the patient simply needs to
relax and stay calm during angiography. Some angiography procedures can take up to two
hours while other procedures take less than an hour.
| Angiogram of carotid artery and
arteries of the brain |
 |
- Once the procedure is finished, the
patient will be given a period of time to recover. During this period, the patient's case
is reviewed on film or monitor.
- Depending on the type of angiographic
procedure and the patient's medical condition, an inpatient recovery may be required or
the patient may be released after a short time. In some cases, more images may need to be
taken. For more information see what happens during a
diagnostic imaging examination?
Therapeutic
(Interventional) Angiographic Procedures
 |
| Conventional angiogram of
descending aorta, kidneys and renal arteries, note the narrowed renal artery seen on the
left (arrow) |
Using angiography to see inside the
body, doctors can repair blood vessels without the use of a scalpel and fully invasive
surgical methods. Advances in the design and use of catheters (small tubes that are guided
into the blood vessels through tiny incisions in the groin area or upper arm) allow
physicians to perform very complex therapeutic procedures from within the blood vessel.
Pathology of the blood vessels such as plaque build up in the arms and legs, neck and
brain, and heart can be treated using a variety of interventional angiographic surgery
(e.g. coronary angioplasty).
Replacing Coronary
Bypass with Coronary Angioplasty
Coronary bypass surgery is a common,
but invasive surgical procedure in the U.S. and is performed over 200,000 times per year
at an average cost of about $25,000. During bypass surgery, synthetic blood vessels or
vessels grafted from other parts of the body are used to create an alternative passage.
This new vessel or "bypass" functions in place of the clogged blood vessel to
feed the heart's tissue with blood, nutrients and oxygen. However, a new technique called
coronary artery angioplasty can be performed without invasive surgery. In this method,
angiography is used to guide surgical stents (small cylindrical supports) into place in
order to re-open clogged blood vessels.
How Does
Angiography Work?
Angiographic x-ray imaging has grown
into its own classification of x-ray imaging over time. The basic principal is the same as
a conventional x-ray: x-rays are generated by an x-ray tube and as
they pass through the body part being imaged, they are attenuated (weakened) at different
levels. These differences in x-ray attenuation are then measured by an Image Intensifier
and the resulting image is picked up by a TV camera. In modern angiography systems, each
frame of the analog TV signal is then con verted to a digital frame and stored by a
computer in memory and/or on hard magnetic disk. These x-ray "movies" can be
viewed in real time as the angiography is being performed, or they can be reviewed later
using recall from digital memory.
During angiography, physicians inject
streams of contrast agents or dyes into the area of interest using catheters to create
detailed images of the blood vessels in real time. During the angiographic procedure,
physicians can guide a catheter into the area of interest to remove stenoses (blockages)
of blood vessels. Patients with blockages of the major leg vessels, for instance, can have
nearly total recovery after angioplasty is performed to remove the constriction.
Updated: September 19, 2007
Return to Medical Procedures Main
Menu |
