Intravascular Angiography

 

Intravascular Angiography

Angiography

  • Angiography or arteriography is a medical imaging technique used to visualize the inside of blood vessels and organs of the body.
  • This is traditionally done by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques called fluoroscopy.

 

  • In Greek, words
    • Angeion = "vessel“
    • Graphein = "to write" or "record

 

  • Fluoroscopy is a medical imaging technique using a constant source of x-ray to show a live presentation of the inner structures of the human anatomy.
  • Fluoroscopy is similar to radiology in the sense of using the source of x-ray and the detectors but differ in the exposure time and the representation of the obtained image.

Coronary angiography

Coronary Angiography

  • Coronary Angiography is a type of X-ray used to examine coronary arteries. The images created during an angiography are called angiograms (or angiograph).
  • A Coronary Angiogram is a special X-ray test performed to find out if the coronary arteries are clogged, where and by how much. 
  • The invasive procedure starts by making a small incision and inserting a flexible guidewire into a large vein through a catheter towards the location of plaque. 
  • The exact location of the catheter will be monitored either by dynamic pressure reading from the tip of the catheter or by the help of fluoroscopy.
  • Once in place, a dye that is visible by X-rays (contrast dye) will be injected into the bloodstream to highlight the blood flow and the borders of the arteries.
  • The fluoroscopy system takes a series of images which will show any areas of narrowing. 
  • It can show severe lesions, plaque disruption, luminal thrombosis, and calcification.

 

Coronary Angiography

Contrast media:

  • Radiocontrast agents are per definition of drugs, but lack therapeutic effects. Contrast medium is used to enhance the visibility of internal structures in X-ray-based imaging techniques such as fluoroscopy.
  • Modern intravenous contrast agents are typically based on iodine. This may be bound either in an organic (non-ionic) compound or an ionic compound. 

Iodine-based contrast media are usually classified as: 

  • Ionic 
  • Non-ionic
  • Ionic contrast media typically, but not always, have higher osmolality and more side-effects.
  • Non-ionic contrast media have lower osmolality and tend to have fewer side-effects.

Contrast media

Ideal CM(contrast media) in Angiography 

  • Water soluble 
  • Chemical and heat stable 
  • Biologically inert (no antigenic) 
  • Low viscosity 
  • Low or Iso-osmolar, excreted 
  • High osmolality
  • Selectively through the kidney 
  • Safe
  • Inexpensive

Some Example
Ideal CM(contrast media) in Angiography