CAROTID          ANGIOGRAPHY

It is used to demonstrate abnormalities and displacements of vessels to anterior and middle part of brain. It is carried our either by direct injection of contrast medium into carotid artery following needle puncture/cannulation or by catheter technique from femoral artery with tip of catheter in common carotid artery. A manual film changer which takes 3-5 films can be used. Subtraction is valuable in visualising vascular pattern

PREPARATION OF PATIENT

1. Basic skull and chest films must be obtained in advance.

2. Patient must have nothing to eat or drink for 5 hrs before the procedure.

3. All radiopaque objects, e.g., dentures and hair pins must be removed.  

CONTRAST MEDIUM AND DOSAGE

Conray 280 or angiografin,10 ml Per injection

PRELIMINARY FILM 

patient lies supine, chin is raised and foam pads placed under e shoulders and neck, which is extended. The X-ray tube is directed horizontally and centred 1 cm above external auditory meatus.

TECHNIQUE 

The injection is made by hand and radiographs are taken to how artery, capillary and venous phase. Usually the first exposure is made when there are about 2 ml of contrast medium left in syringe. The next exposure after 1-2 seconds nd third after 2 seconds again. The needle point must be shown and therefore the cassette must be pushed down into patient's shoulder and supported.

For anteroposterior view, the pads under shoulder are removed. A thin wedge-shaped pad is placed under the head. The table is then raised gently and angled slightly (5-10°) so is easier to position the patient with chin tucked in. The ube is then rotated 90° and angled 25° caudal and centred 2 nch above glabella. For oblique views head is rotated 30° way from side under examination. The tube is centred 5 cm bove mid-point of superior orbital margin of side being examined.

COMPLICATIONS

Can be in the form of:

1. Reaction to contrast medium: Either due to hyper- sensitivity (not dose related) or toxic reactions (when they are dose related). Toxic reactions are commoner in dehydrated patients with generalised ischaemic disease. The hypersensitivity reactions include (rashes), urticaria. bronchospasm, laryngeal edema, and acute anaphylaxis with cardiovascular collapse.

The toxic reactions include a feeling of warmth, cardiac arrythmias, pulmonary edema and cardiac arrest.

2. Complications at local puncture site: Include haema toma, haemorrhage, arterial spasms, thrombosis, sub- intimal dissection, perivascular extravasation of contrast medium, false aneurysm, AV fistula, nerve trauma and local sepsis.

3. Complications distal to the site of puncture: 

Besides subintimal dissection and thrombosis, these include embolization, perforation, catheter knots, guide wire fractures, bacterial endocarditis and septicemia.