Planar scintigraphic imaging of the gastrointestinal tract in clinical practice.

In the last 30 years, nuclear medicine has paralleled other imaging fields with the development of 3-dimensional techniques, including single-photon emission computed tomography and positron emission tomography. However, conventional nuclear medicine planar scintigraphy remains a common procedure at most imaging centers. Gastrointestinal studies constitute a significant portion of these planar procedures. The most common gastrointestinal studies, including hepatobiliary, gastric emptying, and gastrointestinal bleeding evaluations, resemble their original protocol. However, serial improvements have optimized the diagnostic efficacy of these procedures. Conventional Technetium-99m sulfur colloid liver/spleen imaging and hepatic blood pool imaging with labeled red blood cells now mainly serve an adjunctive role in the evaluation of equivocal findings on computed tomography. Salivary gland imaging is a less commonly requested evaluation, but can be used to evaluate functional capacity in some disease entities.