Significance of Ga-67 single photon emission computed tomography in diffuse pulmonary diseases

Ga-67 citrate single photon emission computed tomography (SPECT) was performed in 10 cases of diffuse pulmonary diseases; 5 cases of idiopathic interstitial pneumonitis, 3 cases of sarcoidosis (pulmonary type), 1 case of rheumatoid lung and pneumonia. SPECT image was more excellent and accurate than planar image, because SPECT image was able to distinguish abnormal intrapulmonary accumulation from normal extrapulmonary accumulation; sternum, vertebrae and mammary gland, etc, which were usually overlapping on the planar images. The ratio between intrapulmonary accumulation and vertebral accumulation computed on SPECT images (P/V ratio) was 0.5 ± 0.04 in normal cases. The P/V ratio was elevated in diffuse pulmonary diseases (p < 0.01). (author)