Title:Single Photon Emission Tomography in the Diagnostic Assessment of Cardiac and Vascular Infectious Diseases
Volume: 14
Issue: 3
Author(s): Ismaheel O. Lawal, Janke Kleyhans, Kgomotso M.G. Mokoala, Mariza Vorster, Thomas Ebenhan, Jan Rijn Zeevaart and Mike M. Sathekge*
Affiliation:
- Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria,South Africa
Keywords:
Infective endocarditis, prosthetic valve, cardiac implantable electronic device, left ventricular assist device, vascular
graft infection, radiolabeled leucocyte scan, SPECT imaging.
Abstract: Cardiac and vascular infection is an arising cause of mortality and morbidity in the adult
population. Diagnosis based on culture and anatomic imaging are frequently inconclusive. Radiolabeled
leucocyte scintigraphy plays a useful role in the diagnosis and management of these serious
infectious conditions. In this paper, we present an update on the diagnostic performance of single-
photon emission tomographic (SPECT) techniques using different radionuclides in the management
of patients with cardiac and vascular infections. We performed a thorough search of recent literature
on the topic. We present a discussion on the clinical utility of different SPECT tracers in
cardiac and vascular infections, including infective endocarditis, cardiac implantable electronic device
(CIED) infections, left ventricular assist device infection, and vascular graft infection. Radionuclide
technique using SPECT tracers is a useful imaging modality in the diagnosis of cardiac
infection. Among the different SPECT tracers for infection imaging, radiolabeled leucocyte scintigraphy
is currently the most useful tool in the diagnosis and management of patients with suspected
cardiac and vascular infection. Radiolabeled leucocyte scintigraphy has a high specificity, a result
of the ability of the leucocytes to accumulate as sites of pyogenic infection but not at sites of sterile
inflammation such as seen in the early post-operative period or in response to the presence of a
prosthetic cardiac or vascular material. Limited experience with radiotracers for in vivo labelling of
leucocytes such as 99mTc-sulesomab and 99mTc-besilesomab show acceptable diagnostic performance
without the need for the tedious process of ex-vivo labeling. 67Ga scintigraphy used to be
popular for cardiac and vascular infection imaging. Its use has run out of favor following the availability
of more effective molecular imaging methods. SPECT techniques with radiolabeled leucocyte
scintigraphy has a high diagnostic performance in the evaluation of patients with suspected cardiac
or vascular infection. It is able to confirm or reject the presence of infection when results of
anatomic imaging or culture remain inconclusive. Its diagnostic performance is not compromised
by sterile inflammation occurring in the early post-operative period or in response to implanted
prosthetic materials.
