Site Map |
FAQ |
Glossary |
Health Links |
Contact
 |
| NUCLEAR MEDICINE |
Nuclear Medicine
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, 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 effect 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.
Diagnostic Imaging tests 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, with a gamma camera (a large machine about 60cm across) positioned above and below. The camera picks up the signals (gamma rays) from the radiation that is emitted from the patient and images are obtained of the distribution within the body over a period of time. The scan may take between 5 and 120 minutes, depending on the type of study. For standard images the camera does not move after being set in position. Either a static picture is taken over a set time period or dynamic images (lots of continuous pictures) are taken. Dynamic images can be played back like a movie and used to measure the clearance of a radiopharmaceutical from the organ of interest.
For whole body scans, the imaging bed moves the patient past the detectors. For tomography (SPECT) the detectors move round the patient to form a 3D image. Sometimes tomography is followed by a low dose CT scan; the two sets of images are then fused to enhance anatomical localisation. Image fusion is especially useful in bone scans of the feet.
The Christchurch Hospital Nuclear Medicine Department has two gamma cameras and performs approximately 4,000 scans per year. Patients are referred to the department from public hospitals, private specialists and GPs. Other specialist services provided by the Christchurch Hospital Nuclear Medicine Department include Radionuclide Therapies, Radiopharmacy & Invivo/Invitro Tests and Thyroid Outpatient Clinics.
Imaging services are IANZ Accredited which means that high standards for quality and safety are set and maintained. The department is also accredited with the ANZSNM. The National Radiation Laboratory, NRL is a specialist unit within the NZ Ministry of Health, responsible for regulating the use of ionising radiation.