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WHAT IS NUCLEAR MEDICINE?
Nuclear medicine is the use of radioactive isotopes, usually
attached to a 'tracer' molecule or radiopharmaceutical to allow
images to be taken of various organs in the body. Not only can we
look at the structure of an organ but also how it works! For
example, we can watch the heart beating or how blood flows to the
kidneys.
IS IT SAFE?
Nuclear Medicine has an excellent safety record. The injections
we use are extremely safe, very rarely cause untoward side effects,
and are much safer than those used in other forms of imaging.
WHAT ABOUT THE RADIATION?
While all Nuclear Medicine tests involve some exposure to
radiation, the amount is very small and quite safe. There have
never been any reported side effects from the radiation exposure in
our tests.
WILL I GLOW IN THE DARK?
No. You will feel no effects from the radiation whatsoever. You
will not glow. Your hair will not fall out. Your risk of cancer
will not be significantly increased.
If you are pregnant or breast feeding, please notify us
when making your appointment.
Specific information on each of our tests is listed below. This
includes a brief explanation of the test, how it works, how long it
will take and any preparation required.
Please note that the imaging times given are approximations
only. Every person is different and we will tailor the test to suit
your needs. We are often called upon to perform studies urgently
for hospital patients. These factors make it difficult for us to
always run exactly on time, so your understanding in this regard is
greatly appreciated. We will do our utmost to keep to your
appointment times and if you have special time constraints (eg.
picking up children from school, getting to work, etc) let us know
in advance and we will schedule the day appropriately.
SPECIFIC TESTS
There are many other Nuclear Medicine procedures performed; our
technical or clerical staff are happy to discuss with you the
specific procedure requested by your doctor and any preparation
necessary. If the staff are extremely busy, as you may be yourself,
leave a contact number and we will call you back to answer all your
queries.
Previous tests relating to your condition or area of concern are
always helpful when trying to finalise a well considered report. So
ALWAYS bring relevant
tests/results/reports/ultrasounds and x-rays, etc with you when you
come in for your test.
BONE SCANS
The most common Nuclear Medicine test requested is a bone scan.
A bone scan is a simple and safe procedure for assessing a variety
of conditions related to the skeleton. The scan involves a small
injection of a tracer, which has been specifically designed to be
absorbed into the bones. This tracer contains a small amount of
radiation which will be detected by the Nuclear Medicine
cameras.
The tracer is extremely safe with almost no chance of any
significant reaction. The amount of radiation that you will be
exposed to from a bone scan is less than you would be exposed to
from a CT scan and well within the allowable safety limits. Indeed,
you may have many bone scans over the course of a year without
exceeding the safety limits.
The actual procedure will involve a small injection, usually
into an arm vein. For most conditions, the part of the skeleton we
are most interested in will be under the camera and images will be
acquired immediately after the injection. these images will allow
assessment of soft tissue inflammation and blood flow in this
region. There will then be a delay of at least 2-3 hours to allow
the injection to be absorbed into the skeleton. During this time
there are no restrictions and you can eat and drink freely. Indeed,
we encourage you to drink plentiful amounts of clear fluids over
this time period. There is no need to refrain from emptying your
bladder.
When you return later, images will be taken of the area of
interest, or the whole skeleton if that has been requested by your
doctor. On occasion, additional three dimensional views of the
skeleton may also be required. This whole process will take between
30 and 90 minutes, depending upon exactly what images are
required.
The report is usually available later that day.
Preparation: Drink 1 litre of fluid between
your injection time and the time the images are taken, unless on
fluid restriction. Empty your bladder as required. If the area of
interest is the feet, wear loose fitting shoes with warm socks.
Bring any relevant x-rays and other procedures relating to the area
of concern.
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
GALLIUM
SCANS
Gallium scans are performed in three main situations:
1. For assessment of certain tumours, eg lymphoma -a tumour of
the lymph glands
2. Where there is a concern of infection
3. In certain lung conditions
Gallium is a metal that has the property of being accumulated at
sites of infection or inflammation or by certain tumours. Hence it
can be used to identify sites of the body affected by these
processes. Its uptake is quite slow; therefore pictures are taken
2-3 days after injection.
Tumour Studies:
These are almost always for patients with certain types of
lymphoma. The study is initially to identify the extent of their
disease, and then to monitor treatment. The patient is injected
with gallium and images are acquired 3 days later. Taking these
images requires approximately 90 minutes. You will be asked to lie
on a bed as the camera passes in front of and behind you. A few
pictures of specific areas like the armpits will be taken. Finally,
a 3 dimensional image of your chest or abdomen will be taken. The
excess gallium is washed out through your bowel and kidneys. If
there is a lot of gallium in your bowel at the time of the initial
images, you will be asked to come back a few days later to make
sure this all clears away normally.
Preparation: Nil prior to the injection. After the
injection, a high fibre diet will help clear any excess gallium
from your bowel.
Infection:
Gallium is slow to accumulate at sites of infection; hence you
are normally injected with the isotope early in the week. Images
will be acquired 2 or 3 days later, depending upon the particular
body part being imaged. At the time of imaging, the body part in
question will be placed under the camera and multiple views
obtained. Occasionally 3 dimensional views will be required and/or
delayed views on another day. The scan usually takes between 30
minutes and 1 hour depending upon the body part involved.
Preparation: Nil
Lung Studies:
This study looks for inflammation in the lungs and assesses how
well you have responded to treatment. You will be injected with
gallium and pictures of your lungs taken 48 hours later. These
pictures will take less than 1 hour to obtain. Computer analysis of
the images will then be performed. This can take some time, so we
would normally let you go home and arrange for you to pick up the
pictures later that day.
Preparation: Nil
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
RENAL SCANS
There are two main types of renal scans:
1. DTPA or MAG3 Scans
2. DMSA Scans
DTPA or MAG3 Scans:
These scans are used to assess patients with high blood pressure
and patients with a potential blockage to urine flow. The tests are
quite similar. You will be given an injection into a vein in your
arm, then pictures will be taken over 30 minutes to assess blood
flow to your kidneys and how well they work.
If there is a concern regarding blockage to urine flow, you will
then be given a second injection (lasix) which increases urine flow
through the kidneys, then further pictures will be taken for 20
minutes to watch how well the kidneys respond to this
injection.
Preparation: These tests need you to be well hydrated -
hence we would like you to drink 1 litre of water in the hour prior
to your test.
DMSA Scans:
These scans are used to look for kidney damage secondary to
urine infections. These are commonly used in young children, but
can be performed on adults also. The test involves a small
injection into a vein (generally in the arm) and images are taken
3-4 hours later. Depending on the patient and cooperation from
children, these take between 30 and 90 minutes to obtain.
Preparation: Nil
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
CARDIAC
TESTS
Myocardial Perfusion Scan:
A myocardial perfusion study is sometimes referred to as a
thallium or sestamibi scan. This test is used to assess the blood
supply to the heart muscle at rest and after exercise. It will help
identify the presence and severity of blockages in the blood
vessels supplying the heart muscle. It will also demonstrate
regions of scarring from previous heart attacks.
The test is either performed on a single day or over two days.
This will be dependent on your referring doctor's request, your
history, your medications, and your weight. If you are booked in
for the one day protocol, expect to be in the practice for most of
the day. There is a lot of waiting involved, so bring a book with
you or something to pass the time. You will have a break in
testing, so you may wish to bring your lunch with you. If you are
booked in for the two-day protocol, you will be in the practice for
about half the day on each day.
The test is used to assess and compare the blood supply to the
heart muscle when you are resting and when you have exercised.
For the resting stage, you will be taken into a room where one
of our technologists will check your details and administer the
first injection. The material injected is absorbed by the heart
muscle in proportion to blood flow. We are therefore able to assess
blood flow to your heart when your heart is in a rested state.
Approximately 1 hour after this injection, you will be required
to lie on a bed and images of your heart will be acquired over the
next 30-45 minutes. There will be a wait of between 30 minutes and
2 hours, then the stress phase of the study will be performed. If
the procedure is being performed over 2 days then you will be able
to go home after your first lot of pictures and return on the day
of your second appointment. Remember that there is preparation.
With the stress phase, the study requires a stress to be applied
to the heart. There are three stresses that can be used and your
doctor will select the stress most appropriate to your condition.
The basic format of the test is the same whichever form of stress
is used.
The details of these stress phases will be outlined later, but
in general you will have ECG monitoring, blood pressure monitoring
and a needle in an arm vein throughout the stress. Once the stress
phase is completed, you will be allowed to eat, drink and then take
any normal medications as needed. We request that you avoid fizzy
(carbonated) drinks throughout the testing phase.
Following completion of your later pictures, your involvement in
the test is over and you will be able to leave. Computer analysis
will be performed on the results. This may take up to 2 hours. If
you need your report the same day you should be prepared to wait
approximately 2 hours from completion of the study to collecting
your films.
If at any stage you have questions regarding your test you will
be able to ask either the technologist or the doctor performing the
test on the day.
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
Preparation:
1. Please bring all your medications with you. A list of
your medications is also helpful. If you are on any of the
following medications, please let us know at the time of
booking:
Beta blockers (eg. Betaloc, Inderal, Tenormin,
Lopressor, Visken)
Calcium antagonists (eg. Isoptin, Adalat,
Cardizem, Plendil)
Nitrate tablets or patches (eg. Nitrobid or
Imdur)
Asthma medication (eg. Theodur, Nuelin)
2. Have only a light breakfast in morning (eg. toast and
juice).
3. Omit all caffeine containing drinks and foods
(tea, coffee, cocoa chocolate, coca -cola, etc.) for at least 24
hours prior to the test.
4. Please advise us if you are asthmatic or
diabetic.
5. Prior to your test, diabetics are requested to contact one of
our doctors to discuss your medications: Westmead: (02) 9689 3588,
Penrith: (02) 4732 2722.
STRESS
TESTS
Exercise Stress:
With an exercise stress you will be asked to pedal on an
exercise bicycle. The resistance in the pedals will be
progressively increased. This will be similar to riding a bicycle
up a hill. To get the best results from this test it is important
that you exercise to the maximum level you are able to achieve. One
minute prior to stopping exercise, you will be given a second
injection which will allow imaging of the blood flow to your heart
at stress. Once the exercise is complete, you will be asked to rest
for 10 minutes and make sure that you are feeling well before you
leave.
Persantin Stress:
With a persantin stress, you will be asked to lie on a bed for
10 minutes. Persantin will be injected over 4 minutes. Persantin
increases blood flow through blood vessels. We will be looking to
see that the blood flow through the vessels around your heart
increases normally. In view of the increased blood flow in your
body it is common to feel somewhat light-headed with the injection.
Flushing feelings are also common. Headache can occur on occasion.
Chest pain is a rare side effect of this injection. Two minutes
after the injection of persantin, you will receive a second
injection to allow us to image the blood flow to your heart muscle
at stress. Then two minutes following this, the persantin effect
will be neutralised. The neutralising injection often causes a very
transient feeling of tingling in the face, lips and cheeks.
Please note that persantin will not be given if you have
severe asthma as it can occasionally trigger an
asthma attack.
Dobutamine Stress:
Dobutamine scans are performed in asthmatic patients who are
unable to exercise. You will lie on a bed and dobutamine will be
injected over 15 minutes. Dobutamine will simulate exercise by
causing your heart to beat more strongly and more rapidly. Some
patients will experience an unpleasant tremor towards the end of
the test. Chest pain is a rare side effect. Should you have any
unusual feelings during the dobutamine stress, just notify the
doctor administering the infusion. The effect wears off
rapidly.
Towards the end of the dobutamine infusion, you will be given a
second injection to allow imaging of the blood flow to your heart
muscle at stress. Once the dobutamine infusion is stopped, you will
be observed until all has returned to normal.
Risks and Discomfort:
There is almost no risk from the radiopharmaceutical injection.
Occasional allergic reactions have been noted but are extremely
rare. At all times following the injection, expert help will be
available should you need it. The sestamibi injections contain a
small amount of x-rays. The amount of x-rays contained in the
injection is quite safe and has not been demonstrated to pose any
risk to health.
When any stress is applied to the heart there is some risk. Risk
of a heart attack is extremely rare being approximately 1 in
10,000. The stress may well produce angina if you are prone to
angina. This settles in the vast majority of patients as soon as
the stress is completed or following simple manoeuvres such as
using a nitro-spray or anginine tablets. Emergency equipment and
trained personnel are available to deal with any situation.
If you have any doubts or concerns about this study, feel free
to contact one of our offices and our medical staff will discuss
the test with you in more detail.
Please note: The radiopharmaceutical used for this test
is specifically prepared for each patient and is expensive. If you
are unable to keep your appointment for any reason, please let us
know as soon as possible to allow us to allocate your injection to
another patient.
GATED HEART POOL SCANS
This test assesses how well your heart is pumping or looks for
damage/scarring from heart attacks. You are given two injections
for the test. The first injection binds to your blood cells and
helps the second injection (given to you 15-30 minutes later) bind
to the same cells. We can then watch your blood being pumped
through your heart by taking pictures and making a video.
Preparation: Nil
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
LUNG SCANS
Lung Scans are performed when your doctor is concerned you may
have a blood clot on your lung. The test involves two phases.
Firstly, we get you to breathe in an aerosol that will give us a
picture of the airways to your lungs. Then we give you an injection
which maps the blood flow through your lungs and identifies any
clots blocking the blood flow.
Preparation: Bring a recent chest x-ray.
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
THYROID
SCANS
Thyroid Scans are used to asses your thyroid for a number of
conditions including being overactive, underactive or having
nodules (lumps). The scan involves a small injection into a vein in
your arm with pictures being taken 20 minutes later. The pictures
take between to 10-30 minutes depending on the activity of your
thyroid.
Preparation: If you are on thyroid medication, you may need
to cease this prior to the test. If you have had a CT scan with an
injection in the last 6 weeks or are taking any iodine rich
medications or vitamins (eg, kelp tabs) we may not be able to
proceed with the test. Just let us know when you are making the
booking.
Note: If there is any chance that you are pregnant or
breastfeeding, you should notify staff before proceeding with the
test.
For further Information please refer to our Information for
Patients sheets
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