Patient-specific activity or scan-time in SPECT myocardial perfusion imaging: A hands-on approach

Excerpt

SPECT myocardial perfusion imaging (MPI) is the most validated non-invasive method to test for ischemia, and this procedure is performed over 15 to 20 million times annually.1,2 However, concerns have been raised as SPECT MPI is the single largest contributor to the radiation burden from medical imaging.3 Several approaches to reduce this burden have been studied: stress-only protocols, encouraging appropriate use of MPI, hardware advances, new reconstruction methods, and patient-specific protocols. In our previous studies, we showed that by implementing a patient-specific activity or scan-time protocol, one can drastically lower the tracer activity while image quality becomes less dependent of patients’ size.4 We also showed that such a protocol reduces the radiation dose, while the percentage of scans interpreted as normal and the prognostic value of these patients remains the same.5 However, multiple logistic adoptions are required in clinical practice to implement such a protocol. In this note, we explain how to derive a patient-specific activity or scan-time formula, discuss the pros and cons of several patient-specific protocols, and highlight the practical implications when implementing such a protocol in clinical practice. …