A consistent and systematic approach for the interpretation of myocardial perfusion imaging (MPI) studies is necessary.
Artifact recognition is critical for accurate single-photon emission computerized tomographic (SPECT) and positron emission tomography (PET) MPI studies.
Perfusion defects should be described in terms of extent, severity, and location.
Interpretation of SPECT and PET studies requires an understanding of the different underlying technologies and artifact differences between the two modalities.
Reporting of SPECT and PET imaging data must not only be complete, but also provide a clear and clinically useful conclusion.
The interpretation and reporting of myocardial perfusion images for either single-photon emission computerized tomographic (SPECT) or positron emission tomography (PET) are the key duties of a nuclear cardiologist. The value of these studies lies in the ability of the nuclear cardiologist to accurately interpret the data presented, as well as provide a clinically relevant report to the providers. The use of structured reporting (SR) and templates is strongly encouraged. While many of the concepts of the interpretation of SPECT and PET myocardial perfusion imaging (MPI) studies are similar, there are also some important differences that need to be understood for the successful utilization of both modalities This chapter will present approaches to interpretation of both SPECT and PET data and provide guidance on the reporting of each modality.
INTERPRETATION OF SPECT MYOCARDIAL PERFUSION IMAGES
It is critical that image interpretation be performed in a systematic fashion so as to maximize the clinical value of the study and to ensure the highest-quality result of the entire procedure, providing optimal clinical information and assisting in clinical decision making. As discussed extensively in Chapter 5, the quality of the study must be reviewed and technical abnormalities be recognized. A comprehensive evaluation of all available imaging data must then be performed so as not to exclude potentially vital information.
A number of guidelines and tools have been recommended for the interpretation of myocardial perfusion studies.1–6 These policies and guidelines have been developed by experts in the field and should be used as a guide to the successful interpretation of MPI. This chapter will provide suggestions for approaches for interpretation based upon these recommendations. Of note, as SPECT imaging is the most common technique among patients undergoing radionuclide imaging, the majority of this chapter focuses on the evaluation of perfusion and function with SPECT MPI. Although the methods recommended in this chapter are also largely applicable to PET imaging, there are several important differences between the two, which are addressed in the latter portion of this chapter.
The sequence for interpreting SPECT images should include (1) review of the raw planar images, (2) analysis of the tomographic slices, (3) review of quantitative data, (4) interpretation of gated SPECT data, and (5) incorporation of clinical information (Table 14-1).