The basic science of nuclear medicine

In the era of increasing utilization of cross-sectional imaging in orthopaedic patients with computed tomography (CT) and magnetic resonance imaging (MRI), nuclear medicine (NM) techniques continue to occupy a valuable role in the investigation of these patients. It can provide crucial functional information in a variety of clinical settings that are encountered regularly in orthopaedic practice. It is important that the orthopaedic surgeon is aware of the modalities on offer and appreciates the relative strengths and limitations of these techniques. This article will describe the physical principles underlying NM imaging with single-photon and positron-emitting radiotracers. It will then go on to illustrate the clinical applications of these techniques as applied to pathological conditions of the bone, with particular emphasis on bone scintigraphy and state-of-the-art hybrid imaging techniques, which combine the strengths of functional and structural imaging: single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT).