Dear flow netters
On this ever
evolving and revolving issue of angle correction, I would refer everyone
to a pdf, available on the ICAVL
Look at page 3,
There are many
reasons for this never ending discussion. Not everyone works in an accredited laboratory, nor is
everyone credentialed and we all have varied backgrounds education and
ultrasound experience level. (But as I am the eternal optimist, I can dream of
the day when all labs are accredited and all sonographers
credentialed). I also realize that not
every sonographer gets as excited about ultrasound physics as some of us do and
in fact, some never think about physics again after they pass their
Not all schools are teaching the same
curriculum so we wind up with lots of folks doing things certain ways based on
anecdotal evidence or just because they were told to do things a certain way by
their teachers/trainers who all have
the same varied backgrounds.
So who is the authority ? The physics of
ultrasound and the Doppler equation are great resources to figure this thing
out. ( If you get weak
knees thinking about physics there are lots of folks who will be glad to
help you) Also, look at your cosine tables to see how much info you
are calculating (and losing) by only using 60 degrees. If you study this issue, you will realize that
60 degrees is not the optimal angle for interrogating all
I strongly believe
that one of the absolute responsibilities of being a professional sonographer is
to "not" accept everything we are told on a "just because" we were told basis.
It is our duty to study and learn and think for ourselves.
In my mind, the best
authority here is the organization who will accredit your
You can read
the ICAVL standards document and
draw your own conclusions.
I will leave
you with this thought.
If I ever had
to defend my position on angle correction in a court of law,,,,, I would
certainly like to be able to hold up a document, developed over many years by
respected professionals in my field and say I base my angle correction decisions
based on these standards.
I have never
seen published data that says all velocity based Doppler data should be obtained
at 60 degree angles, no exceptions. Until I do,,,, I believe page 3, section
Donald T. Milburn, NACT RDCS, RVT, FSDMS