Applying standardized uptake value to SPECT/CT: its usefulness and limitations

Introduction: Quantitative analysis can increase inter-observer agreement in evaluating degree of radiotracer uptake in the nuclear medicine studies. Standardized uptake value (SUV) is the most popular parameter used in clinical positron emission tomography/computed tomography (PET/CT) studies. On the other hand, many reports which attempted to apply SUV to single photon emission computed tomography (SPECT)/CT studies have been published recently. Although most of them targeted a bone SPECT/CT using ^99mTc-labelled phosphate compound, SUV may have potentials to improve accuracy and objectivity in evaluating various SPECT/CT studies. Before a practical use of SUV in clinical SPECT/CT studies, we need to understand the characteristics of SUV in terms of not only its general limitations but also SPECT/CT-specific problems. In this educational exhibit, we firstly introduce a method of phantom study for validating the accuracy of SUV calculated from SPECT/CT studies. Next, we review some previous studies which showed clinical usefulness of SUV in various SPECT/CT studies. Finally, we discuss present issues and future perspectives of applying SUV to SPECT/CT studies. Our goal is to invite attendees to the appropriate practice of SUV for evaluating SPECT/CT studies in the clinical settings.