Chapter 16 Nuclear medicine








INTRODUCTION
Nuclear medicine is concerned with providing diagnostic information about patients following the administration of a radioactive product. The patient is imaged using a gamma camera. Images are produced of the distribution of the radioactive substance within different organs and systems. This can be compared with normal distribution to diagnose if a medical condition is present and assess its extent or severity.
Key terms
RADIONUCLIDES USED IN MEDICAL IMAGING
TECHNETIUM
OTHER RADIONUCLIDES USED IN DIAGNOSTIC IMAGING
81mKrypton
Krypton is used for scanning the lungs as it can show the ventilation. It is metastable like technetium and also a pure gamma emitter. It has an energy level of 190 keV, but has a half-life of 13 seconds. This means that the radionuclide has to be produced and then administered directly to the patient. In this case the patient inhales the radionuclide. Air is passed over a column of rubidium, which results in krypton being produced.
EQUIPMENT
Many nuclear medicine departments will utilise one gamma camera to undertake a range of examinations. Some larger departments may employ a dual and a single head gamma camera to perform clinical examinations. Dual head gamma camera systems allow the operator to perform certain examinations (e.g. whole body bone scans) quicker than single head units, which is particularly useful for patients who may be in considerable discomfort.
The basic components of a modern gamma camera detector unit are: