Disadvantages of nuclear medicine procedures compared with other radiographic studies?
- Spatial resolution, usually on the order of 1 to 2 cm, is inferior to that of other imaging modalities.
- Imaging times can be long, sometimes up to 1 hour or more.
- Radiation risk is obviously greater than with magnetic resonance imaging (MRI) or ultrasound (US). However, the radiation risk from most nuclear medicine studies is usually less than that of an average computed tomography (CT) study. Gallium-67 and indium-111 white blood cell studies are the exceptions; they involve an average of two to four times more radiation exposure than other nuclear medicine studies. Positron emission tomography (PET) with CT has the radiation dose of a CT in addition to the radiation from the PET scan. In some studies, such as gastric emptying and esophageal transit studies, radiation risk is insignificant compared with traditional imaging methods, such as fluoroscopy.
- Availability may be limited. Specialized procedures require radiopharmaceuticals or interpretive expertise not available in all centers.
