compounds labeled with radionuclides of shorter physical half-lives (e.g., 10 to 30 min) is, however, not possible through these distribution centers. Their use is therefore confined to institutions capable of onsite radionuclide production and radiotracer chemistry. Labeling of these radiotracers with longer lived radionuclides such as fluorine-18 will be important, because it will provide greater clinical availability and use. This impediment is further explored in Chapters 5 and 6.
Need for Standardization and Harmonization of Nuclear Imaging Procedures. Procedural aspects of nuclear medicine imaging vary, at times greatly, across institutions and thus may complicate or in some instances even preclude meaningful assessments of the clinical value and efficacy of nuclear medicine imaging. Examples of the characteristics that vary include the timing of image acquisition after radiotracer administration, data handling, and data storage. Accordingly, there is a need for greater uniformity of nuclear medicine imaging, including universally accepted image-derived measures of regional tissue function. Standardization of imaging study protocols, of image formatting, data handling, and data storage, as well as of image-derived parameters, will be especially critical for design and performance of multi-center clinical trials for drug evaluation and determination of efficacy of newly developed imaging approaches.