Transmission and emission scintiphotography of the heart and mediastinum

Radiosotopic imaging of the mediastinal blood pools is a well established technique. Although the method provides data relating to the size and location of these pools, additional valuable diagnostic information can be easily obtained through transmission scintigraphy performed prior to blood pool imaging. From an appropriate external radionuclide source, the radiation passes through the radiolucent chest structures to a gamma camera forming an outline image of the more radiodense structures. Subsequent to the transmission study, an emission study of mediastinal blood pools is obtained. The transmission and emission images are similar in size and directly comparable for evaluation of mediastinal structures. The routine use of radionuclide transmission scintigraphy is recommended as an adjunct to emission scintigraphy in the evaluation of mediastinal tumors, myocardial hypertrophy, and pericardial effusions.