3. Fluoroscopy
Fluoroscopy is an imaging technique commonly used by
physicians to obtain real-time moving images of the internal
structures of a patient through the use of a fluoroscope. In its
simplest form, a fluoroscope consists of an X-ray source and
fluorescent screen between which a patient is placed.
However, modern fluoroscopes couple the screen to an
X-ray image intensifier and CCD video camera allowing the
images to be recorded and played on a monitor.
4.
5. The word itself comes from the Greek words angeion, "vessel",
and graphein, "to write or record".
Angiography or arteriography is a medical imaging technique used
to visualize the inside, or lumen, of blood vessels and organs of
the body, with particular interest in the arteries, veins and the
heart chambers.
The film or image of the blood vessels is called an angiograph, or
more commonly, an angiogram.
The term angiography is strictly defined as based on
projectional radiography; however, the term has been applied to
newer vascular imaging techniques such as CT angiography and
MR angiography. The term isotope angiography has also been
used, although this more correctly is referred to as
isotope perfusion scanning.
6. The technique was initially developed to provide contrasted
x-ray cerebral angiography in order to diagnose several kinds
of nervous diseases, such as tumour, coronary heart disease
and arteriovenous malformations.
It enables the radiologist or cardiologist to see stenosis
(blockage or narrowing) inside the vessel which may be
inhibiting the flow of blood and causing pain.
These blockages may in future lead to heart attack.
8. A long wire called catheter is inserted inside the artery of the leg, near
the thigh crease called Groin.
This catheter is then pushed against the blood flow towards the heart
blindly.
An eye is kept on the tip of the catheter through the fluoroscopy
monitor.
Once the tip reaches the heart area, further manipulation is done to push
the tip in one of the coronary arteries.
Inside the coronary tube, after a lot of trial and error, a radioactive dye
is injected through the hole in the catheter inside the coronary tubes and
further fluoroscopy photographs are taken.
The tip of the catheter is again withdrawn, negotiated inside another
coronary tube and the same photos are taken.
If the dye seems to fill up the coronary tubes completely, the blockages
are probably not there. If the dye can not fill the tubes (as roughly seen
in the photos taken) inside, it is taken as filling defect and indirectly
interpreted as blockages.
9.
10.
11. Angioplasty has come to include all manner of vascular
interventions typically performed in a minimally invasive or
percutaneous method.
Angioplasty is the technique of mechanically widening a
narrowed or obstructed blood vessel; typically as a result of
atherosclerosis
Blockages in the arteries may be caused by hypertension,
diabetes, sedentary lifestyle, smoking,
high cholesterol levels, diets high in saturated fats, and
cardiovascular disease. Removing blockages is done with
angioplasty.
12. When there are blockages in the blood vessels of our body
then these can be very harmful to us.
These may not let the free flow of the blood.
All parts of the body may not get requisite supply of the
blood.
Angioplasty is used to tackle with this problem.
In this blockages are removed from the blood vessels so as to
maintain the blood supply to the organ.
14. An empty and collapsed balloon on a guide wire, known as
a balloon catheter, is passed into the narrowed locations.
It is then inflated to a fixed size using water pressures some
75 to 500 times normal blood pressure.
The balloon crushes the fatty deposits, so opening up the
blood vessel to improved flow, and the balloon is then
collapsed and withdrawn.
15.
16. Stents are used in the process of angioplasty so as to make the
cross-section of the blood vessel wider and thereby curing
the blockages in the vessel.
The blockages in the blood vessel may be very harmful.
Stents hold the walls of the vessel and thus not let it sag or
it’s area to shrink.
17. The materials used in coronary stents must be flexible,
supportive, capable of expansion, and biocompatible.
The ideal coronary stent surface does not cause a reaction in
the human body.
It should be quite resistant to corrosion.
Must be strong enough to bear the pressure.
Easy to manufacture.
18. Most stents are built on a stainless steel platform. But
unfortunately, stainless steel is not fully compatible with the
human body
An alternative platform materials such as gold, titanium, cobalt-
chromium alloy, and several types of polymer can also be used.
Gold is biocompatible and usually inert, as well as highly visible.
Cobalt-chromium has proven to be effective stent materials.
Tantalum is a shiny, flexible, and highly radio-opaque though is
more brittle than stainless steel, has proven to be quite resistant to
corrosion.
Certain polymers have found use as a stent materials. E.g. Silicone
19. DISAD..
If it gets stuck somewhere on the route, it is withdrawn a
little and again pushed in. Not only it scratches the whole
length of the arterial tubes of the body but it can also
puncture any corner of the tubes.
Stent surface after biodegradation can be very uneven and, as
such, can induce various cells to adhere to the surface.