Molecular Imaging and Therapy (formerly known as Nuclear Medicine) has been around since the beginning of the 1900s and is a branch of medicine that uses radioactivity for diagnosis or therapy.
Unlike x-rays, CT and MRI scans that give structural information, Molecular imaging demonstrates the function of an organ or organ system by monitoring the passage, accumulation, or excretion of a radiopharmaceutical (a radioactive pharmaceutical).
To perform Molecular Imaging, the radiopharmaceutical 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 or system.
Many injuries or disease processes tend to affect the function of an organ before the structure is altered. Molecular Imaging plays an essential role in helping with the early diagnosis of a wide variety of diseases and conditions, which in turn can make treatment timelier and more effective.
Specialist services provided by Molecular Imaging and Therapy Christchurch Hospital include; Diagnostic Imaging, Radiopharmacy and Radionuclide Therapies.
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 signals (gamma rays) from the radiation that is 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.
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Electronic order entry (e-referral)
Molecular Imaging Requisition form QF00287.
Email the form to Nucappointments@cdhb.health.nz
For clinical criteria, refer to Bone Pain Pathway or Thyroid Pathway.
ACC funded Bone Scans must be referred by a Specialist.
Clerical
Full name of patient i.e. legal name including all middle names with correct spelling
Date of birth and NHI number
Mailing address including postcode, email if available
Contact telephone numbers (include cell for txt reminder).
Name of Referrer and Practice
Service Requested
ACC number if applicable, include date and details of accident
Clinical
Provisional diagnosis and /or presenting problem
Severity and duration
Current medications/ known allergies
Relevant patient history
Relevant Patient Information
Any disabilities, mobility or cognitive problems, special needs e.g. interpreter, hoist etc.
For URGENT scansphone reception (03 3640 867, ext. 80867, 8am - 4pm). Urgent requests are performed as soon as possible, a referral is required before any booking can be made.
All efforts are made to scan patients within the requested time frames and according to clinical triage guidelines.
Routine appointments are generally booked and sent out within a week.
Some types of scans are grouped together and others are only available on certain days.
Some specialised scans are not routinely available, contact Molecular Imaging and Therapy for advice before ordering.
Positron Emission Tomography (PET) is used to demonstrate the metabolic activity of organs and other tissues such as tumours. A radioactive compound called 18FDG (fluorodeoxyglucose) is injected into the patient and the radioactive emissions are measured by a PET/CT scanner. PET is considered particularly effective in identifying whether certain types of cancers are present, if they have spread and if the patient is responding to treatment.
Te Whatu Ora, Waitaha Canterbury does not have a public hospital PET facility. A private PET facility is located at;
Pacific Radiology - Southern Cross
129 Bealey Avenue
Christchurch
www.pacificradiology.com/services/pet-ct
The Radiopharmacy is an integral part of the Nuclear Medicine Department that deals largely with the preparation, dispensing and quality control of radio-pharmaceuticals.
Most of the doses used in diagnostic imaging 
use the radioactive element Technetium-99m which is obtained from a small Molybdenum-99 Generator, delivered to the department at the start of each week. Technetium is often mixed with a non-radioactive compound in order to localise the radiopharmaceutical in a specific area in the body.
Other types of radioactive compounds may be used for specialised scans or therapies. They must be used within a set period of time, which is dependant on the radioactive half-life or decay time (the time it takes for a radioactive substance to loose half its radioactivity).
Each type of Nuclear Medicine procedure will have a prescribed radiopharmaceutical and radioactive dose, measured in MBq. The amount of radioactivity is kept as low as possible and is individually calculated for children based on weight. 
The dose is usually administered by IV injection into a vein in the arm (pictured) but can also be given subcutanously (Sentinal Lymph Node), orally (Gastric Emptying) or breathed in as a gas (Lung Ventilation Scan).
The short 6-hour half-life of Technetium means that the radiopharmaceutical will clear rapidly from the body. Some radiopharmacuticals may also be cleared through the urine or excreted in breast milk.
For some scans, adults are advised to avoid close, continuous, contact with children for the rest of the day (refer to appointment letter).
It is important for us to know if you are Pregnant or Breastfeeding.
In Molecular Imaging, every precaution is taken.
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: |
Imaging services are IANZ Accredited which means that high standards for quality and safety are set and maintained. |
Indications
Thyrotoxicosis (Thyroid overactivity)
Multinodular goitre
Thyroid cancer
Healthinfo.org.nz Radioiodine for Thyroid Cancer
Healthinfo.org.nz Radioiodine Treatment for Thyrotoxicosis
How the Radioiodine works
Radioiodine works by destroying a large number of thyroid cells. The treatment is most commonly given in a drink of water or as a capsule, similar in size to an antibiotic capsule, the radioiodine has no taste. Occasionally more than one treatment is required.
How safe is Radioiodine?
Radioiodine is a very safe and effective treatment that has been used since the 1940's. Patients will be radioactive for a short period following therapy and will need to observe some simple measures to reduce radiation exposure to other people during this time. Most patients develop hypothyroidism (thyroid underactivity) following treatment. Close follow-up with blood tests is necessary to detect this so that replacement thyroid hormone (thyroxine) can be started early.
Referral process
Patients are referred to the Thyroid Endocrine Physicians for treatment. The Physicians will discuss the indications and outcome fully and give radiation protection instructions. For Canterbury patients, follow-up will be arranged at the Thyroid Clinic.
Indications
Metastatic prostatic carcinoma
How the Strontium-89 works
Strontium-89 behaves like calcium in the body, when injected it will collect in the bone metastases (secondaries). These are areas of bone which are absorbing extra calcium and are often painful. It will then deliver radiation directly to the affected area, giving relief from pain.
How safe is Strontium-89?
The effects of Strontium-89 within the body are limited to the small area where it concentrates. It cannot cause any harm to any other people by bodily contact. However during the first few days after injection, some strontium-89 will be present in the blood and urine so the patient will be instructed to observe rigorous hygiene during this time.
Referral process
Patients are referred by an Oncologist licensed to give this therapy. They will discuss the indications and outcome fully and give radiation protection instructions. Molecular Imaging and Therapy staff will arrange the Strontium-89 delivery, dispense the dose and organise the patient appointment.
Molecular Imaging and Therapy
2nd Floor, Riverside Block
Christchurch Hospital
Molecular Imaging and Therapy
Christchurch Hospital
Private Bag 4710
Christchurch 8140
99mTc-HIDA evaluates hepatocellular function, gallbladder function and patency of the Biliary system by tracing the production and flow of bile from the liver, through the Biliary system into the small intestine.
Although ultrasound is the preferred imaging investigation for the diagnosis of acute cholecystitis, biliary scanning has high sensitivity and specificity for diagnosing this condition. If the gallbladder is not visualised this may indicate cystic duct obstruction and supports the diagnosis of acute cholecystitis. False negatives can occur in acalculus cholecystitis (1-2% of cases), and false positives can be seen with chronic cholecystitis, pancreatitis, and prolonged parenteral nutrition.
The response to IV morphine is used to diagnose sphincter dysfunction after cholycystectomy. Opiates increase sphincter tone and therefore precipitate attacks of biliary type pain in some people
In some cases IV morphine may need to be given to enhance gallbladder filling.
Biliary scans can also show gall bladder filling and emptying as a measure of gall bladder ejection fraction in patients with episodes of biliary type pain and non-diagnostic ultrasound examinations.
Diagnosis of acute cholecystitis.
Assessment of gall bladder function with CCK or Ensure.
Assessment of patients with post cholecystectomy pain syndrome and suspected Sphincter of Oddi Dysfunction SOD (requires IV morphine administration).
Distinguishing Biliary Atresia from hepatitis in neonates with jaundice.
Distinguishing Focal Nodular Hyperplasia from other hepatic lesions.
Demonstration of choledochal cysts.
Detection of post-operative bile leaks
Nil by mouth for at least 4 hours (2 hours for infants) and preferably overnight, but no longer than 24 hours -the patient should not be on parenteral nutrition
Opiate drugs must be discontinued for 6 - 12 hours.
Infants with suspected biliary atresia should be pre-treated with 5mg/kg of oral phenobarbitone for 3-5 days prior to the scan.
Sequential images of the liver and abdomen are obtained for 1 - 2.5 hours.
Patients with suspected S.O.D. may require a second scan without morphine at least 2 days after the scan with morphine. Each scan takes 90 minutes.
Patients with suspected gall bladder dysfunction are given a 30 minute IV infusion of CCK after the gall bladder has filled. Ensure Plus (a liquid food drink) may sometimes be given instead of the CCK. The whole procedure takes approx. 2.5 hours.
Neonates with suspected Biliary Atresia may require additional views up to 24 hours, depending on the initial findings.
Bone agents such as HDP localise in regions of increased bone blood flow and increased bone turnover. Almost all significant pathologic processes cause alteration in these physiological parameters, causing increased or occasionally decreased tracer localisation.
Combining the delayed scan with blood flow and pool study and/or SPECT/CT imaging usually enables a definite aetiological diagnosis to be made.SPECT/CT provides better classification of indeterminate non-diagnostic bone lesions and it enables precise anatomical localisation of bone turnover abnormalities.
Bone scanning is a well-established technique, and is one of the most reliable, sensitive and valuable procedures in nuclear medicine. The scan can detect abnormalities weeks to months before routine skeletal x-rays. It is particularly useful for assessing patients with pain suspected of bony origin, and evaluating sports injuries. It remains the most cost-effective imaging procedure for assessing skeletal metastatic burden.
Detection, evaluation and follow up of skeletal metastases.
Detection, evaluation and follow up of primary bone tumours.
Early diagnosis of osteomyelitis and infected joints.
Evaluation of hip and knee prostheses and degenerative joint disease.
Diagnosis of stress fractures or occult fractures.
Diagnosis of avascular necrosis, particularly when the condition is post-traumatic.
Establishment of the extent and activity of Paget's disease.
Evaluation of elevated alkaline phosphatase.
Evaluation of bone pain of uncertain cause.
Diagnosis of enthesopathy, bursitis and reflex sympathetic dystrophy.
Patients need to have a good fluid load between injection and scanning (6 glasses of fluid).
Scanning is performed 2 – 4 hours after IV injection of 99mTc-HDP and takes approximately 45 minutes. A 10 minute scan may also be performed at the time of injection to determine blood flow to a region of interest.
99mTc-HMPAO is a lipophyllic complex that accumulates in the brain proportional to regional perfusion. The SPECT images reflects regional cerebral uptake at the time of injection.
In Alzheimers, one classically sees bilateral decreased CBF in the temporal and parietal lobes. A correlation is seen between the severity of these defects and the severity of the patient's dementia.
Lewy Body Dementia (LBD) is the most common cause of dementia after Alzeimers and vascular dementia and is characterised by decreased CBF in the occipital lobe.
Frontal Temporal Dementia (FTD) is characterised by decreased frontal/temporal lobe perfusion.
Multi infarct dementia is characterised clinically by multiple cerebral infacts that occur sporadically and produce a step-wise deterioration in function. 99mTc-HMPAO findings, which support this diagnosis, include multiple, bilateral, and randomly distributed cortical perfusion defects that follow vascular territories. The basal ganglia may also be involved (spared in Alzheimer's).
To distinguish frontal lobe dementia patterns from parieto-temporal lobe disease.
The presence of sedating medications at the time of injection may alter the distribution of 99mTc-HMPAO. A list of the patient's medications will be required by Nuclear Medicine staff, who will advise which, if any, need to be withheld.
If problems with cooperation are envisaged, this should be noted on the referral. If anxiolytic or sedating medication is required (administered at least 15 minutes after the radiopharmaceutical injection), this must be prescribed by the referring doctor or GP and accompany the patient.
On arrival, an IV line is inserted. The patient is left lying comfortably in a dim, quiet room for about 20 minutes, after which 99mTc-HMPAO is injected.
SPECT/CT imaging takes place about 30-90 minutes later and takes about 30 minutes. The patient will need to keep their head perfectly still during this time.
Parkinson's Disease and several other syndromes are characterised by the degeneration of dopaminergic cells, resulting in the loss of Dopamine Transporters (DATs) in the striatum. 99mTc-TroDAT binds to the dopamine transporter, its uptake is significantly reduced in the striatum of patients with Parkinson's Disease.
DAT imaging is helpful to differentiate tremor disorders from idiopathic Parkinson's Disease.
DAT imaging can also help differentiate Dementia with Lewy Bodies from Alzheimer's.
Medications that interfere with DAT binding are stopped after consultation with the referring Physician.
If problems with cooperation are envisaged, this should be noted on the referral. If anxiolytic or sedating medication is required this must be prescribed by the referring doctor or GP and accompany the patient.
99mTc-TroDAT is administered IV, 4 hours before the scan.
SPECT/CT imaging takes about 30 minutes. The patient will need to keep their head perfectly still during this time.
Gastric emptying studies are performed to evaluate patients with symptoms that suggest an alteration of gastric emptying and/or motility. They provide a physiologic, noninvasive and quantitative measurement of gastric emptying.
Gastroparesis is the term used to describe non-obstructed causes of delayed gastric emptying. Diabetes mellitus and gastric surgery are the two most common causes of chronic gastroparesis. Other causes include acid-peptic disease, gastritis, chronic pseudo-obstruction either primary or secondary to neuropathies, muscular or connective tissue diseases, epigastric disorders and gastric dysrhythmia. Drugs and hormones may also be responsible for delayed gastric emptying.
Accelerated gastric emptying is usually iatrogenic after gastric surgical procedures such as a vagotomy. After a vagotomy there may be decreased 'receptive relaxation' of the fundus which permits food to more rapidly exit the stomach, despite the decreased motility. Patients with duodenal ulcer, the Zollinger-Ellison syndrome, malabsorption or hypothyroidism may also have rapid gastric emptying. Patients with dumping syndrome show a rapid passage of solid and liquid meal into the small bowel, with minimal initial retention in the proximal stomach.
Suspected slow or rapid gastric emptying.
The study is usually performed about 8.30am after an overnight fast.
Patients should not smoke/vape or have tea, coffee, caffeine drinks or alcohol for 24 hours prior to the study.
Drugs affecting gastric motility should be stopped 24 -48 hours previously.Gastroprokinetic agents (48 hours), Proton-pump Inhibitors (withhold morning of scan), Opiate Analgesics (48 hours), Anticholinergic, antispasmotic agents (48 hours), Macrolide Antibiotics e.g. Erythromycin
If the patient is diabetic then a blood glucose level needs to be completed before eating.
A standard meal of scrambled egg on toast and milk is given to the patient. The egg is pre-labelled with a technetium colloid and the meal is standardised for fat, carbohydrate, protein, and total calorie content.
Immediately after completing the meal a 2 minute image is taken.
Further images are taken at 30 minutes and 1, 2, 3, 4 hours later.
The patient must remain in the department, sit upright and not have anything more to eat or drink until the study is complete.
The gastric clearance half-life of the meal is calculated and the % emptying/retention.
The study should be performed while the patient is actively bleeding. Although the test is sensitive and can detect intermittent bleeding, it may not always localise the exact anatomical site. SPECT/CT can be used to provide anatomical localisation when bleeding is detected.
To detect sites of active GI bleeding prior to angiography and/or surgery.
The patient's red blood cells are labelled with a radiotracer, this takes about 40 minutes.
Images are acquired for approximately 1 hour and then at intervals up to 24 hours after injection, or until bleeding is detected. Sites of active bleeding can be identified on serial views of the abdomen and pelvis.
Gated heart imaging (MUGA scan) is a well-established, relatively inexpensive and accurate method for evaluating cardiac size, wall motion and function.
The test should not be used for direct evaluation of valve motion, or estimating myocardial thickness. Cardiac Echo Studies are the procedure of choice for assessing these parameters.
Assessment of volume, wall motion, and function of LV.
The patient's red blood cells are labelled with a radiotracer.
The camera is centred over the cardiac blood pool and imaging of the heart is synchronised with the patient's ECG.
Scan time is approximately 30 minutes, the entire procedure takes approximately 1 hour.
The radiopharmaceutical 99mTc-DTPA is ideal for measuring GFR because it is neither reabsorbed nor metabolised by the kidneys and only excreted from the kidney through glomerular filtration. Following IV injection of a known amount of radiopharmaceutical, three blood samples are collected at approximately 2-hourly intervals. The GFR is calculated by counting the radioactivity emitted from the blood samples (plasma clearance over time).
Monitoring patients on renal toxic drugs e.g. some types of chemotherapy
Kidney transplant donors
Clinical situations where an accurate GFR measurement is required.
It is the responsibility of the department/ ward ordering the test to inform the patient.
NO IV fluids or diuretics from 6 hours before, or during the procedure.
NO radionuclide scans in the past 3 days or recent radionuclide therapy.
NO CT or PET contrast either in the past 5 days or during the procedure.
NO MRI contrast for 24 hours prior to or during the procedure.
The GFR test is usually performed on Wednesdays and Thursdays. Medical staff are advised to send a referral with the preferred date and phone ext. 80867 to confirm the booking.
Doses are prepared in the radiopharmacy and are ready to pick up at 08:45am. A GFR Instruction Sheet and Worksheet will accompany each dose.
Injection of the dose is the responsibility of the requesting department/ ward. It is important to allow time to gain venous access as the dose must be injected before 09:30.
IV luer or Butterfly- inject the dose into an antecubital or peripheral vein; rinse the syringe several times with blood after injecting to ensure the total dose is administered. Flush the butterfly or luer with 5-10 ml of NaCl. Remove the luer, place in Kidney dish.
Dual lumen Hickman - flush with 5ml NaCl, *Remove the PPD and inject the dose directly through the white lumen. Flush syringe with blood x2 to ensure dose is completely through the lumen. Flush with 3x10ml NaCl using pulsatile flush, replace the PPD.
Keep the dose syringe+cap along with any butterfly/ luer, swabs, saline flushes, gloves etc used during the injection and return to Molecular Imaging.
If any of the dose is spilt or tissued, the GFR calculation will not be accurate. If this is suspected, phone Molecular Imaging immediately to receive advice on whether or not to continue - the patient or items will need to be monitored by our staff.
Record the exact injection time on the Worksheet along with the patient's height and weight; these figures are used to correct the GFR result for body surface area.
Withdraw blood samples at approximately 2, 4 and 6 hours after the injection of the radioisotope. Use 10ml green top heparinised tubes and fill each tube to the same level. Full tube for adults, at least 5ml for children.
Collect the blood samples from another arm or at least a different vein from the injection site. If using a Hickman, take all samples from the red lumen and discard the first 5 ml of blood before sampling.
Note the exact time of each sampling on the worksheet. Sampling does not have to be exactly on the hour but the precise time of sampling must be noted – use the same clock/watch if possible.
Ensure the last sample is taken before 3pm and return all samples immediately to the Nuclear Medicine Department for processing by 3:15pm.
Results are usually available the same day.
The radiopharmaceutical 99mTc-Scintimun' used for Infection Imaging, contains an antibody which targets granulocytes (a type of white blood cell involved in inflammation and fighting infection).
SPECT/CT is of value in distinguishing physiological uptake of labelled white blood cells from infectious processes and defining the precise anatomical location of infection. The major limitations of white cell scanning are poor sensitivity for chronic inflammations and/or abscesses, and localisation of WBCs in sterile necrotic tissue.
Detection and localisation of acute inflammation/infection e.g. vascular graft infection, FUO (fever of unknown origin).
Use in conjunction with other appropriate imaging modalities for determining the location of inflammation/infection in peripheral bone and in adults with suspected osteomyelitis.
Evaluation of suspected prosthetic joint infections
The procedure is contraindicated if the patient has a known allergy to mouse antibodies or has previously had a Scintimun scan.
Medications reducing inflammation; corticosteroids and antibiotics may affect the scan results.
If evaluating prosthetic joints, a bone scan is usually performed first.
After IV injection of 99mTc-Scintimun, patients need to have a good fluid load between injection and scanning (5 glasses of fluid).
Scanning is performed at 4 - 5 hours and 24 hours. This takes 45 - 60 minutes.
Labelled heat denatured red blood cells are avidly sequestered by the spleen, allowing for selective splenic imaging. Splenic tissue is easily identified as an area of high RBC activity or sequestration. Correlation of anatomical (CT or US) and functional spleen-specific images will often be necessary in many cases to determine the nature of left upper quadrant mass. Though accessory spleens may have been seeded anywhere in the abdomen, most of them are located in the left upper quadrant.
Identification of accessory splenic tissue following splenectomy.
Confirmation of questionable abnormalities of the spleen e.g. trauma.
On arrival, a blood sample is taken, the 99mTc-heat damaged RBC are injected IV about 45 minutes later.
Imaging of the abdomen and pelvis takes place after about 30-90 minutes. SPECT/CT is used to precisely localize splenic tissue.
Liver haemangiomas are probably the most common benign tumour of the liver. Because of their prevalence, they are often discovered during CT or ultrasound examination of the abdomen. Accurate diagnosis is essential because inadvertent biopsy of an haemangioma can lead to significant haemorrhage.
Detection of haemangiomas using the 99mTc-RBC technique is virtually 100% accurate for lesions greater than 2cm, however very small lesions (1cm) may not be detected. The haemangioma appears as an area of marked RBC pooling within the liver.
To confirm a suspected haemangioma seen on CT scan.
It is preferable the scan is not done within 4 days of a barium meal or CT contrast of the abdomen.
The patient's red blood cells are labelled with a radiotracer.
Images of the liver are acquired immediately after injection and at 90 - 120 min after injection. SPECT/CT is valuable in providing anatomical localisation.
Although CTPA has become the preferred investigation for suspected PTE, in most centres, lung scanning is still a useful test. It is more sensitive than CTPA but not as specific. The lung scan is most useful when the CXR is normal and there is no evidence of COPD.
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Lung VQ scanning should be considered when CTPA is negative or indeterminate and there is a high clinical likelihood, and when there is a contraindication to CTPA (impaired renal function or iodine allergy).
It is the recommended investigation for young women and in women who are pregnant or breastfeeding as there is a lower radiation dose to the breasts from a VQ scan compared to CTPA. Investigations for Suspected PE in Pregnancy - CDHB Blue Book.
A high likelihood lung scan is sufficient for the diagnosis of PTE in most patients. A normal perfusion scan excludes the diagnosis.
Diagnosis of pulmonary embolism.
Quantitation of regional lung perfusion and ventilation.
The patient should have had a D-dimer test and chest x-ray within 24 hours.
The scan should be performed within 72 hours of a clinical suspicion of the diagnosis.
note: SPECT-CT is not performed on pregnant women in order to minimise the radiation dose to the foetus.
Small radiolabelled colloidal particles are injected into lymphatic rich epidermal areas. The particles are small enough to move freely in lymph vessels and are temporarily trapped in nodes.
Lymphoscintigraphy is a technique used to identify the Sentinel Lymph Node (SLN), this is the first node that drains from a tumour. If the node is biopsied and found to be tumour free, then the likelihood of nodal spread of tumour is very low. The SLN is identified in the operating theatre using a specially designed radiation probe and a blue dye.
Assessment of patients with suspected lymphoedema.
Identification of sentinel lymph node (SLN) prior to surgery.
The length of the procedure, (1–3 hours) should be noted when organising a patient's theatre schedule.
If the patient has early morning surgery, the SLN procedure should be arranged for the afternoon before.
Suspected lymphoedema
4 x 0.1ml of 99mTc-nano-colloid are injected into the web spaces of the hands or feet.
Images are taken immediately and after 2 hours.
Sentinel Lymph Node - Breast Carcinoma
2x 0.1ml of 99mTc-nano-colloid are injected subcutaneously in the periareolar region of the affected breast.
During the waiting time, the patient is asked to massage the breast to encourage lymphatic flow.
Images are taken 1 - 2 hours later. The position of the node/s is marked on the skin.
Sentinel Lymph Node - Melanoma or Merkle cell
2x 0.1ml of 99mTc-nano-colloid are injected subcutaneously either side of the melanoma or merckle cell scar.
Images are usually taken immediately after injection and approx. 2 hours later. SPECT/CT may be used for anatomical localisation. The position of the sentinel node or nodes are then marked on the skin.
Meckel's diverticulum is the most common congenital abnormality of the gastro intestinal tract, present in 2% of the population. It consists of a small pouch in the wall of the intestine, near the junction of the small and large intestine, made of the type of tissue found in the stomach (gastric mucosa). Gastro intestinal bleeding is the most common complication in the paediatric age group.
99mTc-Pertechnetate is concentrated by the gastric mucosa, therefore imaging of the abdomen following IV injection of pertechnetate should demonstrate any areas where there is increased tracer uptake. The Meckels scan is a simple, safe and noninvasive diagnostic procedure to show ectopic gastric mucosa, which is present in most cases of symptomatic Meckel's diverticul. The technique will only detect diverticulae with significant ectopic gastric mucosa.
Structurally, MIBG resembles norepinephrine and guanethidine. MIBG localises to storage granules in adrenergic tissue of neural crest origin. Uptake is proportional to the number of neurosecretory granules within the tumour.
123I-MIBG is an expensive radiopharmaceutical and must travel a long distance before administration. Currently, MIBG is labelled to Iodine-123 in Japan, then put on a flight to Christchurch via Sydney, arriving late afternoon every second Thursday. It must be injected the same day and the scan is performed on Friday afternoon (18-24hr later). A minimum of 2-3 week's notice is required to arrange the study.
MIBG sensitivity in the detection of neuroblastoma has been reported to be 90% or greater, specificity approaches 100%. The extent of metastatic bone and bone marrow disease is most accurately defined by MIBG scintigraphy however small liver mets may escape detection due to the high concentration of MIBG in the liver. The accurate depiction of the full extent of disease spread and distribution are essential before therapy for both prognostic classification and therapeutic decisions.
MIBG sensitivity for pheochromocytomas is 80% and specificity 95-99%. CT and MRI are accurate in detecting primary tumours of the adrenal gland but they are inferior to MIBG in the detection of extra adrenal tumours.
Neuroblastoma
Phaeochromocytoma / Paragangliomas
The patient should not have a bone scan less than 2 days before or until 5 days after the Iodine-123 MIBG injection. A GFR study should not be performed until at least 6 days after the Iodine-123 MIBG injection.
The patient must not have either CT with oral contrast or a Barium study less than 5 days before the Iodine-123 MIBG injection or until after imaging has finished (usually 26 hours after the injection). These x-ray studies will interfere with MIBG scanning.
Lugol's Iodine (thyroid blocking agent) needs to be started 1 day before the Iodine-123 MIBG injection and should be continued for 3 days. 1 or 2 drops to be taken daily in milk.
Foods such as chocolate (including chocolate milk), can block the uptake of MIBG. They must be avoided for 4 days before the MIBG scan.
Certain drugs interfere with MIBG uptake and should be avoided (usually for 3 biological half-lives): Decongestants and nasal sprays, Tricyclic Antidepressants, Antipsychotics/Tranquillisers, Amphetamines, Antihypertensives.
The patient will have an IV cannula inserted ready for the injection to be given ASAP after arrival. Children are usually given the 123I-MIBG via a Hickman line.
The imaging is performed 18-24 hours later. This takes approx. 1.5 hours (including SPECT/CT).
Infants and young children will need sedation or anaesthesia as they must remain still during the scan.
Myocardial agents such as Sestamibi and Tetrafosmin are markers for viable, perfused myocardium. A perfusion abnormality on an exercise scan that returns to normal on a repeat rest study indicates reversible myocardial ischaemia.
Myocardial Perfusion Scans (MPS) are useful in assessing the extent and severity of myocardial ischaemia. It is critical to correlate the results of ECG testing and clinical data with scan results. MPS aid in pre-operative evaluation by helping to determine the amount of scar versus ischaemia present. The scan is often used to assess the significance of an equivocal stenosis seen on angiogram and to triage patients into medical or surgical management programs. The MPS also provide valuable data on LV size, volume and LVEF.
The greatest strength of MPS are their prognostic value. A negative MPS predicts a low risk and low annualised cardiac event rate of 0.6% per year for 3 years.
Detection and evaluation of known or suspected coronary artery disease.
Follow up of medical or surgical therapy of coronary artery disease.
The patient should fast at least 3 hours prior to the Rest study and have only a light lunch before the Stress study.
The patient should not have any food or drinks containing caffeine (tea, coffee, coke, chocolate) for 24 hours before the first study and until both studies are complete.
The patient should withdraw from beta-blockers for 48 hours (from the day before the stress study, continuing until the end of the study).
Nitrates and calcium channel blockers must be stopped for 24 hours before the study.
Myocardial Rest and Stress studies take approx. 2 hours each. They are usually performed on the same day (Rest Study in the morning and Stress Study in the afternoon) but they can be on separate days if required.
On arrival, an IV luer is inserted and ECG leads are attached. All metal items (including bra) must be removed from the chest area.
There is a waiting time of approx. 30min between IV injection and scanning. Each scan takes about 20 minutes.
The Stress study can be achieved by exercise bike, Persantin, Dobutamine, Adenosine or a combination of exercise and pharmacological stress. ECG recordings are made throughout the study and the injection is given after reaching peak heart rate.
Sestamibi is actively taken up by parathyroid adenomata and has a slow washout from these lesions compared to normal parathyroid tissue. The scan is normally done in conjunction with a technetium thyroid scan because thyroid adenomas may also show increased retention of Sestamibi.
99mTc-Sestamibi Parathyroid imaging can be useful in the preoperative detection and localisation of parathyroid adenomas in patients having proven hyperparathyroidism (sensitivity of 90%). SPECT/CT provides topographic correlation with adjacent anatomical structures; this imaging technique can identify a single adenoma, multiple adenomas, ectopic adenomas or hyperplastic glands.
Localisation of suspected parathyroid adenoma. It is not a screening test for hyperparathyroidism.
A Thyroid scan is usually performed a few days before the Parathyroid study unless the patient is on Thyroxine or has had recent IV contrast.
Parathyroid scans involve early imaging including SPECT-CT soon after IV injection, this takes about 45 minutes.
Later Parathyroid images are taken approx. 2 hours later.
PSMA is a trans membrane protein with a significantly increased expression in Prostate Cancer cells. The PSMA expression increases progressively with higher grade Prostate Cancer, Prostate Cancer Metastasis and Castrate Resistant Prostate Cancer. 99mTcPSMA can detect recurrent lesions in different locations, such as local recurrence, lymph nodes, bone metastases, and visceral metastases. Detection rate and sensitivity correlate to PSA levels and lesion size.
DMSA has a high affinity for proximal tubules and produces superb images of the renal cortex. Renal scanning can readily detect the number, size and position of any functioning kidney. The study is very sensitive in detecting any renal cortical abnormality and exceeds that of an IVU or ultrasound. It is considered the gold standard for screening for cortical scars.
Determination of number, size and position of kidneys and quantitative assessment of relative function of each kidney.
Assess known reflux.
Assessment of children with recurrent UTIs. Scan at least 4 months after last UTI unless on prophylaxis.
Evaluation of renal pseudotumours.
Scanning begins about two hours after IV injection of 99mTc-DMSA and takes about 20 minutes.
A longer time between administration and scanning will be necessary if renal failure is present.
The most widely used radiopharmaceutical is 99mTc-MAG3. It is excreted by both glomerular filtration and tubular secretion and can be used in patients with renal failure and in patients allergic to IVU contrast agent. The Renogram can be used to evaluate renal perfusion and renal obstruction. Differentiation of obstructive vs nonobstructive hydronephrosis can be made by initiating a brisk diuresis with Frusemide (Lasix). In an obstructed hydronephrosis, washout of activity does not occur, while washout of activity occurs if obstruction is not present. Similarly, in a nonobstructive system cortical transit times should be essentially normal.
Differential diagnosis of obstructive vs. non-obstructive collecting system (with Frusemide provocation and measurement of transit times).
Evaluation and follow up of renal obstruction
The patient should be off diuretics for at least 24 hours if possible, and should be well hydrated.
On arrival, adults are given 1 litre of water to drink over 30 minutes.
An IV injection is given and continuous images are recorded for the next 30 minutes. A diuretic is administered during the scan.
On completion of the 30-40 minute scan a further image is taken after bladder emptying. The entire procedure takes about one hour.
Thyroid scanning is a well established test for evaluating many thyroid diseases. The scan helps to classify the goitre into diffuse or multinodular goitres. Thyroid nodules can be classified into those that concentrate tracer (hot nodules) and those that do not (cold nodules). Distortions and extensions of the gland beneath the sternum can be seen. The thyroid scan aids in the evaluation of hyperthyroidism by demonstrating findings that differentiate Graves' disease, toxic adenoma, toxic multinodular goitre and thyroiditis.
Evaluation of goitre and nodules.
No thyroid hormone (Thyroxine) for 6 weeks prior to the scan, a patient can be scanned if they have been on Thyroxine for 5 days or less.
No Iodine based CT contrast 4-8 weeks prior to the scan.
If the patient is on Amioderone, refer to Thyroid physician.
Kelp, Chinese herbal remedies or iodine/potassium iodide in multivitamins need to be stopped for at least 3 weeks if 200µg or more.
Following an IV injection of 99mTc-Pertechnetate, there is a waiting time of approx. 20 minutes
The scan takes approx. 10 minutes to complete.
Molecular Imaging and Therapy
2nd Floor, Riverside Block
Christchurch Hospital
Molecular Imaging and Therapy
Christchurch Hospital
Private Bag 4710
Christchurch 8140
Molecular Imaging - Your Visit (PDF, 150KB)
Molecular Imaging - Your Child's Visit (PDF, 150KB)
Information for Health NZ Staff (Doc)
* only available to staff with access to Health NZ Waitaha Canterbury Intranet.
Nuclear Medicine Newsletter March 2020 (PDF)
Nuclear Medicine Newsletter February 2016 (PDF)
Nuclear Medicine Newsletter March 2014 (PDF)
Nuclear Medicine Newsletter March 2012 (PDF)
Molecular Imaging and Therapy
2nd Floor, Riverside Block
Christchurch Hospital
Molecular Imaging and Therapy
Christchurch Hospital
Private Bag 4710
Christchurch 8140
For most scans the waiting time is only 2-6 weeks however, if the scan takes a long time or is more specialised, the waiting time could be longer. Kidney scans following a Urinary Tract Infection are booked months after the UTI according to accepted clinical protocol.
If you are concerned and have not received an appointment within 2 weeks, contact Molecular Imaging to check that we have received a referral from your doctor.
For some scans, the radiopharmaceutical takes time to travel through the body and concentrate in the organ of interest. At the first appointment you will receive an injection and depending on the type of scan, images may also be taken at this time. At the later appointments time/s on the same day, images only will be taken. The exception is a Myocardial Perfusion Rest/Stress scan which has injections at both times.
Specific appointment letters are sent out which give details of any special preparations. Please read them carefully. For most scans you can eat and drink normally and keep taking your usual medication.
Phone Molecular Imaging. It is usually advisable to delay the scan until after pregnancy unless there is a clinical reason for doing otherwise. Breastfeeding mothers will be given instructions and advice depending on the type of scan they are having, as only some radiopharmaceuticals are excreted in breast milk.
We would welcome this as long as they are not young children or a pregnant woman.
A very small needle is used for the injection, which is in a volume of no more than 1ml. A vein in the arm is usually used, although sometimes a hand or foot is more suitable, especially in babies and young children. It will feel similar to a blood test or pin prick. If you have difficulty with blood tests or IV access, please contact Molecular Imaging ASAP.
This is a compound which is usually made by mixing a radioactive isotope with a non-radioactive formula. Different compounds are used to study different parts of the body. Over 90% of scans use radioactive 99mTechnetium which has a physical half-life of only 6 hours and an even shorter half-life in the body.
The injection will not make you feel any different and side effects are very rare. You will NOT glow in the dark!
NO. The radioactivity used has a short life and is quickly eliminated from the body. Even though the radioactivity is injected, most radionuclide scans involve the same amount or less radiation than that from x-ray or CT procedures.
Every possible precaution is taken to minimise the radiation exposure to as small an amount as possible while still obtaining the needed diagnostic information. All babies and children under 18 years old are weighed on arrival and the dose of radioactivity is calculated according to weight.
This will depend on the type of scan. In some cases part of the radiation is excreted in the urine and therefore leaves the body quite rapidly.
Radioactive 99mTechnetium decays to a non-radioactive form over a period of 2 days, after 24 hours (4 x half-lives) there will only be very small quantities remaining.
While we do not consider the radiation emitted a hazard, we have the responsibility to keep radiation exposure to others as low as reasonably achievable.
For some scans, adults are advised to avoid close continuous contact with children and pregnant women for the rest of the day. It is safe to share a bed with your partner on the night of your scan, unless otherwise directed.
Children are advised not to sleep in the same bed as other children and not to go back to school, kindergarten or crèche until the day after the scan. It is preferable to use disposable nappies for the day of the scan and at home normal hygenic measures are sufficient. Remember to wash your hands.
There are no restrictions for handling pets.
You will not need to remove all your clothing. Usually shoes and metal objects around the area being scanned are all that is necessary, for example you will not need to remove your rings or watch unless the scan is of your hands and wrists. If you have a prosthesis, we may require you to remove it.
You will need to be able to roll up your sleeve to the elbow for the injection. The technologist will tell you exactly what is required before you start your scan.
NO. It is different altogether from an MRI scans, however please let the scanning staff know if you have a metal implant.
The beds are about 40cm wide and hold patients up to 180 kg. Although the beds can be lowered, anyone who is immobilised in a wheelchair will need to be able to transfer themselves across. If you think there may be difficulties please phone the department before the scan.
You will not be enclosed and only certain types of scan will require the camera near the head e.g. bone scans of the whole body or upper body, thyroid, cardiac, lung and brain scans. You will not be left alone, a technologist and friend/ relative can stay close by.
The camera is quiet and you may listen to music or wear eye shades if this helps. You are welcome to bring your iPod, MP3 player to listen to during the scan. Phone the department before the procedure if you wish to discuss your concerns with staff.
We use velcro bands to keep younger children still during the scan however movement is not totally restricted. The camera has a DVD player attached and we have a limited selection of DVDs for children to watch while they are being scanned, though parents are welcome to bring along any favourites. We also have a limited selection of books and toys.
Distractions such as reading a story, watching a DVD or listening to a music tape are usually effective in reducing movement. You may stay close to your child during the scan. Babies may be more settled if they have the comfort of a pacifier, bottle or toy.
A specialist doctor trained in Nuclear Imaging will report the scan and forward the results electronically to the doctor who requested the scan. In most cases the results are available within 24-48 hours.
The pictures are stored on computer (PACS) which can be accessed by both private and public specialists; if the referring doctor is a GP then a paper copy will be posted.
Molecular Imaging and Therapy
2nd Floor, Riverside Block
Christchurch Hospital
Molecular Imaging and Therapy
Christchurch Hospital
Private Bag 4710
Christchurch 8140
Page last updated: 11 April 2024
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