The patient lies on the table as the table
is moved slowly into the Scanner gantry (Donut). The Gantry
houses the rotating xray tube and xray receptors.
The original scanners in 1978 took 2 minutes
per slice and had very rough images. The new scanners
today can do a series of 30 images in a few seconds and
have much sharper images.
Contrast Material: For Abdominal CAT Scans,
the patient is given a cup of dilute barium or Gastrograffin
the night before and also 1 hour before the Scan to delineate
the small and large bowel.
The
Scan may be done twice. First before and secondly after
intravenous iodinated contrast (Same iodinated IV contrast
used for IVP test see above). The iodinated contrast enhanced
the vascular structures and improved interpretation of
the CAT Scan images.
Possible
Risks and Complications: The IV contrast is usually injected
with a motor driven power injector and so extravasation
from the vein which causes irritation in the skin may
sometimes happen. There is also a risk of allergy to the
iodinated contrast material resulting in hives, itching,
wheezing, shock etc. Again pretreatment with Benadryl
and Predisone usually eliminates reaction in allergic
patients.
CAT SCAN showing lesions in the Spleen
