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Skills and interest
Medical ultrasound
Is performing ultrasound
scanning in general practice irrelevant and not safe enough? Because of
its noninvasive and comparatively accessible nature, ultrasound is a useful
adjunct investigation for some clinical problems in general practice.
The advantages
of medical ultrasound are many:
| 1. |
It is safe and
non-invasive. There is lack of ionizing radiation and no need for
contrast material. |
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| 2. |
It is portable
and convenient to use. |
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| 3. |
It can be done
in multiple planes, thus increasing the diagnostic accuracy. |
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| 4. |
Cystic and solid
lesions can be differentiated. It is highly accurate in diagnosing
simple cysts. |
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| 5. |
Measurements
can be done, e.g. to measure kidney sizes, bile duct diameter. |
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| 6. |
It has high sensitivity
and accuracy for detecting gallstones and intrahepatic and extrahepatic
duct dilatation. |
One of the areas where
ultrasound is widely used is in upper abdominal problems. Some of the
indications for upper abdominal ultrasound are:
Ultrasound is the
primary and mostly definitive investigation of gall bladder disease despite
recent improvements in other noninvasive imaging modalities.
Oral cholecystography
and intravenous cholecystography are no longer performed. CAT scan is
not helpful and MRI is expensive and not readily available.
Ultrasound has very
high diagnostic accuracy for gallstones.
Ultrasound is the
best initial imaging procedure and is accurate in diagnosing biliary dilatation
which suggest obstructive jaundice, and in localizing the level of obstruction.
In problems such as
acute cholecystitis, ultrasound shows thickened gall bladder wall and
often presence of gallstones, and the RUQ pain can be elicited by gently
pressing the gall bladder with the ultrasound transducer (positive ultrasound
Murphy's sign).
One important thing
to notice is that ultrasound scanning is operator dependent. It
depends on the operator's clinical knowledge, technical skill and knowledge
of the equipment being used. When there is any query about the diagnosis,
the client should be referred to specialist for further investigation/management.
Common diseases
of the abdomen encountered in general practice are gallstones, gall bladder
polyps (potential of malignant change if >1cm), fatty liver (generalized
or focal), liver haemangioma, liver and renal cysts, renal stones. Less
common ones are hepatomegaly, cirrhosis, enlarged or atrophied kidneys
Local course
that may interest you is the Diploma in Medical Ultrasound jointly organized
by SPACE, HKU and Hong Kong College of Family Physicians. Basic principles
of ultrasound are taught, and practice on use of ultrasound on abdomen
is supervised by experienced radiologists.
Details of the course
are printed in the College News in Vol.24 No. 7, July 2002 of the "The
Hong Kong Practitioner"
Some overseas courses
in Australia and USA, etc. can also be found in the following website
(click 'Links' and find "Australian Institute of Ultrasound"):
http://www.aiu.edu.au/
References
| 1. |
Lecture Notes,
Diploma in Medical Ultrasound (jointly organized by SPACE, HKU and
HKCFP). |
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| 2 |
Janes A Bates.
Abdominal Ultrasound: How, Why and When. 1999. Churchill Livingstone. |
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