The usefulness of 99mTc-MIBI in the detection of active pulmonary tuberculosis

The use of radiopharmaceuticals in evaluation of pulmonary tuberculosis may help to resolve difficult diagnostic problems such as discordance between sputum examinations and chest roentgenographic findings. We investigated the usefulness of 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy in the detection of active pulmonary tuberculosis. Forty-six patients with suspected active pulmonary tuberculosis were studied with sputum smear of AFB, sputum AFB culture, chest X-ray and MIBI scan. MIBI image was obtained 15 and 60 min after intravenous injection of 370MBq(10mCi) 99mTc-MIBI. In 16 patients of them Ga scans were performed in addition to MIBI scan. Repeated MIBI scans were done in 7 patients with active pulmonary tuberculosis after 4∼6 months of antituberculous chemotherapy. Thirty-two patients were confirmed as active tuberculosis by sputum culture. Sensitivity of MIBI scan to active tuberculosis was 87.5%(28/32) and MIBI findings were negative in all of 14 patients with inactive disease. Focal uptake of MIBI was dense in the area that was strongly suggested active tuberculous lesions by chest roentgenogram. There was no discordance between MIBI and Ga image in 16 patients. But the uptake areas of Ga images were broader than that of MIBI images. After 4∼6 months of antituberculous treatment all repeated MIBI scans revealed negative findings except 1 patient with persistent active pulmonary tuberculosis due to drug resistance. MIBI scan could be used in the detection of active pulmonary tuberculosis as a useful noninvasive diagnostic tool