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This information is provided by
Provet for educational purposes only.
You should seek the advice of your
veterinarian if your pet is ill as only he or she can correctly advise on the
diagnosis and recommend the treatment that is most appropriate for your pet. Radiographic
films are widely used in the veterinary profession as an aid to diagnosis, but
a disciplined approach to reading them is rarely applied outside referral
centres and practices with a member of staff holding a post-graduate
qualification in the subject. It
has been estimated that 80% of errors in radiology are due to a failure by the
film reader to observe a visible lesion. For example, in trauma cases
clinicians relatively easily recognize and document the obvious bone lesions,
but they may fail to identify and record associated soft-tissue lesions. There
are certain procedures that can be used to help to avoid errors in film
reading :
- Always take radiographs of the
anatomical site being investigated in at least two projections (at 90o
to each other)
- Make sure that the radiographs
that you have taken are of diagnostic quality. Change the
radiographic exposure and repeat them if necessary to get good films
- If you are not sure about your
findings - compare the image(s) with known normal and abnormals - in your
own reference library of images, or in a reputable textbook.
- If you are examining a single limb
and you are not sure whether a finding is abnormal or not, take a similar
radiograph of the other limb for comparison.
- Remember that the XRay film is a photographic image and try to interpret
it in two stages :
- Describe what you can see on the image - radiographic description
- Interpret your photographic description - radiological
interpretation
- Always look at everything on the
image
- Develop a routine approach to
reading films and stick to it. For example - abdominal radiographs can be
interpreted in several ways :
- an organ system approach - eg
start with the alimentary tract, then the urogenital tract and so on;
or
- a sector approach - eg divide
the abdomen into 6 sectors and examine the lower cranial compartment
first, then the upper cranial compartment, then the lower mid-abdomen
, and so on.
- a radiographic-density
approach - identify and describe the most radiodense (white) areas
(usually bone) on the image, then work through shades of grey until
you get to the most radiolucent (black) areas (usually gas)
- Don't let your eyes rush to an
obvious lesion (e.g. a fractured bone) - force yourself to interpret the
whole radiographic image in a systematic way...you are much less likely to
miss something, and you are most likely to recognize some secondary lesion
of importance.
- For each identifiable anatomical
structure ask the following questions :
- Has it normal/abnormal
radiodensity ?
- Is it in a normal/abnormal
location in the body ?
- Does it have a normal
anatomical relationship with neighbouring structures?
- Has it a normal/abnormal
contour (outline) - e.g. rough/smooth ?
- Does it have a normal/abnormal
shape
- Is it normal/abnormal in size
(increased/decreased) ?
- Is there any other abnormal
radiographic finding. e.g. is an expected finding absent?
- Describe and document all abnormal
findings in detail.
- Sometimes the hardest thing to do
is to say that a radiographic feature is NORMAL.
- Try to read radiographic films
without referring to the case history. In veterinary film reading sessions
there have been many instances when a radiographer has picked up a
radiographic finding by reading a film blind, and this has subsequently
redirected the primary clinicians investigations towards an accurate
diagnosis.
Practice Tip 1
Form your own radiographic library of
normal and abnormal films to compare with radiographic films from difficult
cases.
Practice Tip 2
Try to get all the clinicians in your
practice together for 30mins-1 hour at least once a week to re-read the
radiographic films that the practice have taken. Encourage each other to
question the diagnosis and to identify missed radiographic findings.
Last updated : October 2013
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