Tc-99m MIBI uptake in pulmonary sarcoidosis. Preliminary clinical results and comparison with Ga-67.

During tumor imaging research, the authors incidentally discovered that Tc-99m MIBI is taken up by pulmonary sarcoidosis. In order to evaluate this uptake, they performed Tc-99m MIBI planar and SPECT imaging in 7 patients and compared it with Ga-67. Six out of 7 patients showed evident uptake of Tc-99m MIBI in enlarged hilar lymph nodes. One of the patients, who had been on corticosteroid treatment, showed only faint uptake (negative result), in whom Ga-67 uptake was seen in hilar lymph nodes although it was less evident than the uptake in the other patients. The lymph nodes were better demonstrated with Tc-99m MIBI. The fact that enlarged hilar lymph nodes in a patient on corticosteroid treatment showed faint uptake suggests that Tc-99m MIBI could be helpful for assessing the response to treatment. The preliminary experience in a limited number of patients showed that Tc-99m MIBI is taken up by pulmonary sarcoidosis and it appears to be a potential alternative to Ga-67. Further study is necessary to evaluate its ultimate role in pulmonary sarcoidosis imaging.