Imaging in medicine
Imaging in medicine

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

Imaging in medicine

6 Radionuclide imaging

6.1 Introduction

Radionuclide imaging is a very valuable way of examining the function of an organ, as opposed to the more structural images obtained by other methods such as X-ray and CT.

The basic principles of radionuclide imaging are as follows:

  • a radioactive substance, usually combined with a biologically active compound, is injected into the patient;

  • this targets a particular organ or tissue type;

  • the radiation emitted is detected and used to form an image of, or the function of, that organ.

The most common radioactive substances used emit gamma rays (usually in the energy range 100–300 keV). More than 95 per cent of all gamma camera imaging techniques use technetium-99m (Tc-99m). This radionuclide is particularly useful because:

  • it produces only gamma rays (by isomeric transition);

  • the gamma rays have an appropriate energy of 140 keV;

  • the physical half-life of Tc-99m is about 6 hours, so injection and imaging can take place in a reasonable period of time but the patient does not remain radioactive for a long period;

  • it can readily be combined with biologically active substances to form a variety of radiopharmaceuticals.

Tc-99m is produced by the beta decay of molybdenum-99 by the reaction:

S809_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has over 40 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus