CT Interpretation What is a CTA computed tomography (CT) scan is
an imaging method that uses x-rays to createpictures of
cross-sectionsof the body.With plain X-ray, you get a single shot
of X-ray beams and you get a single image. With CT, you get a
couple of hundred X-rays and the computer puts them all together to
give you a set of images.Risk As with any medical procedure, there
are risks and benefits. The main risk is radiation. This
predisposes to cancer.If you have a 4-month old child, you would
have to have a very good reason to do a CT scan. As they are
growing, there's lots of mitosis going on and a much higher chance
that you do damage to a gene and pre-dispose somebody towards
cancer.An 80 year-old female with a background of MI, severe COPD
and end-stage lung cancer is very amenable to CT. Even if she
develops a neoplasm, it is unlikely to kill her.InterpretationBlack
is airWhite is bone, contrast or metalGrey is everything
elseEssentially, if they have given contrast, it will appear as
bright white on the scan. Metal, like hip replacements, appear
white as well. Soft tissues tend to appear grey, empyema appears
grey, fat appears grey, colon appears grey etc
Note: YOU ARE LOOKING FROM THE BOTTOM! When you see a CT scan,
imagine you are at the end of the bed. The front is at the top, the
back is at the bottom, the patient's left is on the right and the
patient's right is on the left. Got it?
ContrastCT scans may be done with or without contrast." Contrast
refers to a substance taken by mouth or injected into an
intravenous (IV) line that causes the particular organ or tissue
under study to be seen more clearly.This is contraindicated in
renal failure (acute or chronic) - if you have an eGFR
