Nuclear Medicine

Nuclear Medicine, or Scintigraphy, uses radioactive tracers that are injected into a vein to assess the function of organs at a molecular level. Radiation doses are comparable to x-ray examinations. Reactions to the tracers are extremely rare and the tests are therefore exceptionally safe and well tolerated.


    Nuclear Medicine is a branch of diagnostic imaging that uses trace amounts of radioactive pharmaceuticals to map the function of many organs and body systems. Common areas are the heart, bones, lungs, kidneys, liver, stomach and thyroid gland.

    Nuclear Medicine can provide a rapid and accurate diagnosis of a wide range of medical conditions when used alone or in conjunction with other imaging tests.

    The tracer, usually injected into an arm vein, concentrates in the area of interest. A gamma camera moves close over the area, building an image from the radiation emitted. A complex digital system then analyses, stores and displays the images that are evaluated by our medical imaging specialists.

    Nuclear Medicine provides unique functional and physiological information to diagnose problems that often cannot be gained from other imaging examinations. This information is used to implement the best health care for patients.

    All Astra Radiology nuclear medicine technologists are accredited and registered with the Medical Radiation Technologist Board (MRTB) New Zealand.

  • BEFORE a Nuclear Medicine Scan

    A referral form from your doctor or medical specialist, and an appointment is required for this examination. 

    If you have insurance, you will need prior approval which can be organised by our bookings team. 

    If it is an ACC claim, we will need your ACC claim details. 

    If you are pregnant, breastfeeding, or caring for a small child on the appointment day, please notify us in advance to receive special instructions. 


    When you attend your appointment at Astra Radiology you will be asked to answer a few safety questions. If you would rather not get changed, wear clothing and underwear without any metal present to your appointment.

    The technologist will explain the scanning procedure. The radioactive tracer will then be injected into an arm vein. In some instances, imaging starts immediately, and you may breathe normally but must try not to move. Initial imaging takes 20 to 30 minutes.

    Some procedures are two-part, or multi part test, requiring delayed scanning. This will be discussed with you at the time of booking your Nuclear Medicine scan.

    The gamma camera is a large square radiation detector which sits close to the area being examined. In some procedures, it rotates around the body while acquiring images. You will experience no unusual sensations or discomfort from the scanning process.


    Radiation from the injected isotope diminishes to a very low level a short time after the procedure, and you are free to resume normal activities. If you are caring for a small child, or breastfeeding, we may ask you to take some minor precautions.

    You may resume your normal activities immediately after the procedure is completed.

    If your results are needed urgently, or you have an appointment straight after your scan with your referring doctor or health care provider, Astra Radiology will arrange to have your results available immediately. Otherwise, your referring doctor or health care provider will receive your report within 48 hours of your examination.

    Please ensure that you make a follow up appointment with your referring doctor or health care provider to discuss your results.


    Nuclear medicine examinations are considered very safe with almost no reported adverse reactions attributable to the radiopharmaceuticals used in these examinations.

    Nuclear Medicine studies require very small doses of gamma radiation and are only performed where the benefits of the examination are deemed to outweigh any potential risks. At Astra Radiology you can be assured that using the latest technology and with staff trained in radiation reduction techniques, radiation doses are kept as low as reasonably possible.

    If you are worried or concerned about having a Nuclear Medicine study, you should discuss this with your referring doctor or medical specialist before coming for your examination.

    If you think you may be pregnant, please inform our Nuclear Medicine team before your examination.


A bone scan is a nuclear medicine test using a small amount of radioactive tracer that is injected into the arm vein to image the function of the skeletal system. It is useful in assessment of spinal fusions and implants, evaluation of painful hip and knee prosthesis and in diagnosing and managing conditions such as fracture, inflammation, infection and tumours in bones. 

SPECT/CT can be performed as part of your bone scan. It provides finer resolution data of the areas of interest, improving the sensitivity of the scan been performed. 

This technique involves the acquisition of a low dose non contrast CT after (or before) a SPECT which uses a rotating gamma camera.  This is done immediately on the same scanner. 

The thyroid uptake scan uses a gamma camera and small amounts of radioactive tracer injected intravenously, to produce images and measure the function of the thyroid gland. The images show the size, shape and function of the gland, and any nodules or irregularities. It is often used in conjunction with ultrasound. 

A nuclear renal scan examines the blood flow and function of the kidneys using a small amount of a radioactive tracer that is injected into an arm vein. A gamma camera placed over the kidneys images or maps the pattern of tracer passing through the kidneys, giving information useful in diagnosing conditions such as obstruction, low or uneven function, scarring and bladder reflux. 

A sentinel node scan is a nuclear medicine procedure in which a small amount of radioactive tracer is injected under the skin and imaged using a gamma camera, mapping the lymphatic system around an area requiring surgery. 

The V/Q, or lung ventilation and perfusion scan uses a gamma camera and small amounts of radioactive tracer to take images of the air and blood supply to the lungs. Its most common use is to diagnose a suspected clot on the lung (pulmonary embolus). 

The G.I. Bleed Study (or bowel haemorrhage scan) is a type of nuclear medicine scan which uses a Gamma Camera and an injected radioactive tracer (radiopharmaceutical) to take images to detect bleeding in the small or large bowel. 

The Hepatobiliary scan (also called HIDA scan) uses a small amount of injected radioactive tracer (radiopharmaceutical) and a gamma camera to examine the function of the gallbladder and the liver as well as the Sphincter of Oddi (SOD). Its main use is to diagnose gallbladder inflammation or blockages in the bile ducts, or SOD dysfunction. 

The colonic transit study uses a small amount of radioactive tracer (radiopharmaceutical) and a gamma camera to examine the function of the colon. This is an extended study taking up to five consecutive morning appointments to complete. Its main use is in diagnosing disorders of bowel motility (ability to pass solid waste spontaneously). 

The parathyroid scan uses a gamma camera and a small amount of radioactive tracer (radiopharmaceutical) injected intravenously to examine abnormalities of the parathyroid glands in the neck. Its most common use is in diagnosing benign tumours (called adenomas) which cause the parathyroid glands to become overactive. The test is usually done in conjunction with ultrasound. 

The gastric emptying scan uses a very small amount of radioactive tracer (radiopharmaceutical) to measure the emptying or processing speed of the stomach. The tracer is incorporated into a small meal, usually eggs on toast with jam, and a gamma camera takes images of its progress through the stomach and bowel. This procedure gives an accurate indication of whether the stomach is functioning normally or is abnormally slow to process food. 

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