NUCLEAR MEDICINE DEPARTMENT
AT CHRISTCHURCH HOSPITAL
Information for Medical Practitioners & Nursing Staff
For hospital staff with access to the CDHB Intranet, the following Information can be found in
the CDHB Policy & Procedure Manual Volume 14: Radiology and Nuclear Medicine
Procedures Performed at Christchurch Hospital.
Nuclear Medicine Procedures at Christchurch Hospital
Name
Authoriser
Date
General Information - Nuclear Medicine
EDON
20 March 2012
Imaging Procedures
EDON
20 March 2012
1 General Information
1.1 Introduction ....................................................................................................... 1
1.2 Imaging ............................................................................................................. 1
1.3 Process of Initiating a Nuclear Medicine Scan.................................................. 2
1.4 Reports ............................................................................................................... 3
1.5 Radiation Dose .................................................................................................. 3
1.6 The "Nuclear Medicine Study" Notice .............................................................. 4
1.7 Accompanying Staff and General Nursing Care ............................................... 4
1.8 Body Fluids ........................................................................................................ 5
1.9 Patient Preparation ............................................................................................. 5
1.10 Patient Information .......................................................................................... 6
1.11 Examination of Pregnant and Breastfeeding Women ..................................... 7
1.12 Adverse Reactions ........................................................................................... 7
1.1 Introduction
Nuclear Medicine is a branch of medicine that uses radioactivity for diagnosis or therapy.
Unlike x-rays, CT and MRI scans that give structural information, Nuclear Medicine
imaging demonstrates the function of an organ or organ system by monitoring the passage,
accumulation or excretion of a radiopharmaceutical. Because injuries or disease processes
tend to affect the function of an organ before the structure is altered, Nuclear Medicine
plays an essential role in helping with the early diagnosis of a wide variety of diseases and
conditions, which in turn can make treatment more timely and effective.
1.2 Imaging
Nuclear Medicine Imaging procedures are often referred to as “scans,”scintigraphy,
“isotope studies or “radionuclide imaging. To perform a nuclear medicine scan, a
radioactive pharmaceutical is first administered to the patient, usually intravenously.
Depending on the type of scan, the pictures may be taken immediately and/or after a period
of time during which the pharmaceutical localises in the target organ/system.
The patient is asked to lie still on an imaging bed. The gamma camera or SPECT/CT
camera is positioned above and below the area/s of interest. The camera detects the gamma
rays that are emitted from the patient’s body. Images are obtained of the distribution within
the body over a period of time. The scan may take between 10 and 120 minutes, depending
on the type of study. The patient is required to lie still for the duration of the scan. It is not
necessary for the patient to fully undress however traction slings may need to be removed.
Different types of images can be acquired:
A Static image is one picture taken over a set time period. Dynamic images are lots of
continuous pictures which can be played back like a movie and used to measure the
clearance of a radiopharmaceutical from the organ of interest. The camera remains set in
one position for these scans.
For a whole body scan, the imaging bed moves the patient past the detectors, imaging from
head to toe.
For tomography (SPECT) the detectors move round the patient to form a 3D image.
Sometimes SPECT is followed by a low dose CT scan (SPECT/CT); the two sets of images
are then fused to enhance anatomical localisation. The main advantages of SPECT/CT are
represented by better attenuation correction, increased specificity and the accurate
depiction of the localisation of abnormal uptake/disease and of possible involvement of
adjacent structures eg. bone scans. Furthermore, SPECT/CT is especially helpful in aiding
the planning of minimally invasive surgery as it assists in pre-surgical localisation eg.
parathyroid imaging.
1.3 Process of Initiating a Nuclear Medicine Scan
To request a Nuclear Medicine Scan, complete the Nuclear Medicine Request Form
QF002787. This form is also available on the CDHB Intranet. Note that the patient’s
weight is a mandatory requirement for most scans.
Deliver or fax the form (ext. 80869) to the Nuclear Medicine Department. For urgent scans
during working hours (Monday – Friday 0800 – 1700), telephone the Scanning room (ext.
80867) after faxing the requisition. Urgent requests are performed as soon as possible.
Availability: All efforts are made to scan patients within the requested time frames
indicated on the referrals. Some scans are only available on certain days and others are not
routinely available (refer to individual scans in Imaging Procedures). Discuss with Nuclear
Medicine staff before ordering these scans.
1.4 Reports
Most Nuclear Medicine scans are reported within 48 hours. All scan reports are available
on Éclair and CIS, and both the images and report are available on PACS. Contact the
Nuclear Medicine Physician for urgent reports and clinical discussion.
1.5 Radiation Dose
Most nuclear medicine diagnostic scans use a radioactive material called Technetium-99m.
Technetium has a short half-life of only 6 hours. The short half-life means that even for
Technetium-based radiopharmaceuticals that don’t clear rapidly from the body, the patient
will receive only a small radiation dose.
Radiation dose can be described in terms of a quantity called ‘effective dose’, which is
measured in millisieverts (mSv). For the procedures listed below, an average effective dose
is quoted. For comparison, the annual natural background radiation level is about 2 mSv
per year. This average level varies according to which part of the country you live in.
X-Ray Examination
NM Investigation
Chest X-ray
Plain Abdominal X-ay
0.05mSv
1.5 mSv
Lumbar Spine X-ray
Lumbar Spine CT
IVU
CT Abdomen & Pelvis
2.0 mSv
3.5 mSv
4.0 mSv
15.0 mSv
Thyroid Scan
Perfusion Lung Scan
0.8 mSv
0.9 mSv
Renogram
Bone Scan
0.5 - 1.4 mSv
3.7 - 5.0 mSv
Note: figures are based on adult doses.
Please contact the medical staff in the department if you require further advice or
assistance with explaining risk estimates to patients.
In Nuclear Medicine every precaution is taken to ensure exposure to radiation is;
Low: only small quantities are used for diagnosis.
Short: the radioactive compounds used in diagnostic tests are quickly eliminated from the
body.
Carefully Controlled: facilities, equipment and materials meet strict safety standards.
1.6 The "Nuclear Medicine Study" Notice
Although many nuclear medicine investigations don’t require any special nursing
precautions, for most in-patient scans a “Nuclear Medicine Study” notice is issued before
the patient leaves the Nuclear Medicine Department. This notice gives recommendations
on how to minimise any radiation hazards associated with caring for these patients. They
are based on a conservative approach to minimising hazards, and it is important to note that
they only apply for the day of the procedure.
1.7 Accompanying Staff and General Nursing Care
If possible do not schedule elective procedures on the same day as the scan e.g. OT,
endoscopy. Please consult with Nuclear Medicine if there is a problem.
For most diagnostic tests, no specific extra nursing care is required except that required by
the patient’s clinical condition. This does not apply to radionuclide therapy, for which
there are special procedures (consult the leaflet accompanying the patient).
For diagnostic tests the risk to staff is extremely low. Even a small distance between nurse
and patient greatly reduces the radiation dose received. This should be noted by escorts
accompanying patients for nuclear medicine studies. Although there is unlikely to be a
significant hazard to the foetus of pregnant escort nurses, it is sensible to avoid
unnecessary radiation to a foetus. Please do not send a pregnant nurse as escort if at all
possible, and do not direct a pregnant nurse to give continuous, close nursing care
(‘specialling’ the patient) during the first 12 hours after a patient has been administered a
diagnostic radiopharmaceutical. The patient does not need to be nursed separately from
other patients.
Patients from outlying hospitals must be accompanied by an appropriately trained staff
member at all times. Prior arrangements can be made in consultation with Nuclear
Medicine Staff, for a suitable place to wait during the period between injection and the
scan. While every effort will be made to minimise the length of time the patient will be
away from the ward, accompanying staff should be aware of and be prepared for
unavoidable and occasionally long delays.
1.8 Body Fluids
In some investigations urine or vomit may be slightly radioactive for a short time. This
constitutes no danger to nursing staff provided they handle the body substances in an
approved manner. Deal with them as biohazard, using Universal Precautions, i.e. wear
gloves, dispose of correctly and wash hands. Flushing bed pans and vomit bowls down the
sluice is acceptable. Catheter bags may be emptied into a sluice or toilet and the urine
flushed away. Contaminated bed linen should be placed in a red linen bag and sent to the
laundry.
It is preferable that a 24-hour urine collection is not made within the day after a nuclear
medicine investigation. If this is unavoidable, a “radioactive‟ sticker can be provided by
the department to inform any staff handling the specimen of the radionuclide it contains.
The specimen should be placed in a side room on the ward where no one will stand beside
it for long periods. It should be taken directly to the laboratory when collection is
complete. The laboratory staff should also be warned, in case the radioactivity should
interfere with their analyses.
Any spill of urine (or vomit), or any body fluid should be thoroughly washed from the skin
and cleared from floors, etc, as is normal for a biohazard. As with any spillage, it is
important that it is contained as soon as possible and not spread around the ward. However,
appropriate patient care always has priority. If any staff are concerned about adequate
decontamination following a spill they should contact the department.
1.9 Patient Preparation
Most investigations within this department require little or no patient preparation (see
Imaging Procedures).
The patient will need to be transferred onto an imaging bed. If the patient weighs over
180kg or specialised lifting equipment is required then inform the Nuclear Medicine staff
when booking the scan.
If the patient is unable to tolerate lying still for the length of the scan due to pain, then
medication will need to be administered before the
start of the scan. If you think that it may be necessary to use sedation (usually reserved for
small children with long scan times), please discuss with Nuclear Medicine staff when
booking the scan.
For some tests eg. Bone scan or Renogram, it is important that the patient is well hydrated.
If a patient is unable to drink, IV fluids may need to be given. Some Nuclear Medicine
scans may require a period of fasting prior to the study eg. Biliary scan. Specific
instructions will be given, as appropriate.
The iodine in contrast media used in radiology may block uptake by the thyroid of the
radiopharmaceuticals used in thyroid or parathyroid scans. It is preferable to perform these
scans before one that involves contrast media, otherwise the Nuclear Medicine scan may
have to be postponed for several weeks.
There are also medications which must be avoided before specific scans because they can
interact with the radiopharmaceutical given (refer to individual scans in Imaging
Procedures).
In most circumstances, an IV luer is not required. However, babies, young children and
adults with difficult venous access may require an IV luer to be inserted by Paediatric
Outpatients or by ultrasound guidance prior to the radiopharmaceutical injection.
1.10 Patient Information
The patient will receive an explanation of the test from departmental staff. However, as
many patients have no idea what is involved, it is preferable for them to receive some
information at the time the test is requested or booked.
Patient information sheets are faxed to the ward when a scan is booked and they should be
given to the patient. An explanation of the test by a member of the medical or nursing staff
should be given at the same time. Outpatients are sent letters specific to the type of scan
they are having, as well as a general information brochure. The brochures are also
available in the CDHB Nuclear Medicine website.
It is particularly important that a pregnant or breastfeeding woman receives an explanation
about the test, or the necessity to interrupt breastfeeding before she comes to the
department. Pregnancy and the postpartum period are an emotionally stressful time, and
radiation in pregnancy has received negative publicity. The patient may wish for the advice
and support of her partner. This is not always available if the explanation of the nature of
the test is left until just before the investigation.
1.11 Examination of Pregnant and Breastfeeding Women
If necessary, some tests can be performed on pregnant women, for example, lung scans
for thromboembolic disease. Pregnancy is not an absolute contraindication to
radionuclide investigations, but routine tests should not be performed on pregnant women
if the result will not affect immediate management and they can be delayed until after the
end of pregnancy. A request for an investigation on a pregnant woman should be
discussed by a senior member of the clinical team responsible for the patient with a senior
member of departmental staff.
Some radiopharmaceuticals are excreted in breast milk. If tests are essential during
lactation then interruption of breastfeeding will be advised for a short period. This time
depends on the pharmaceutical concerned. If possible, the baby should be fed
immediately before the investigation. The mother should be encouraged to express breast
milk during the period of interruption, both for comfort and to ensure continuation of the
supply. This breast milk must be discarded.
Please contact the department for further advice if you wish to perform a study on a
breastfeeding mother.
1.12 Adverse Reactions
There are very few adverse reactions to radiopharmaceuticals. As with any intravenous
injections there is always a risk that allergic rashes or minor vasovagal episodes may
occur. No specific remedy is required, just symptomatic treatment. However, please
report any suspected reaction to the Nuclear Medicine Department.