Clinical Application And Study Of Radionuclide Scintigraphy In Respiratory Diseases

Pulmonary scintigraphy, due to its noninvasiveness and ability to reflect pulmonary physiology, is used effectively both in the diagnosis and study of respiratory diseases in developed countries. However, in our country, its use is quite limited.The first part of this paper introduced the methodology of pulmonary inhalation and perfusion (I/Q) imaging, first pass pulmonary perfusion imaging and Ga-67 lung imaging; and also the semiquantitative data analysis using computer. The measurements of mucocilliary clearance ( MCC) of lungs and pulmonary epithelial permeability (LEP) were established based on the technique of pulmonary radioaerosol inhalation imaging.The second part reported the results of clinical studies of 206 patients using the above mentioned methods.There were 122 cases of COPD, 10 patients with asthma, 21 cases of pulmonary embolism (PE), 12 cases with pulmonary or cardiac right to left shunt, 10 with pulmonary sarcoidosis and 31 with lung carcinoma.Pulmonary MCC was evaluated in 17 COPD patients and LEP in 19 cases with interstitial lung disease or lung sarcoidosis.Our results indicate that:1. A pulmonary perfusion/inhalation imaging should be performed as the first screening test in patients suspected of PE. The " high probability" of I/Q has a predictive value >90%. I/Q also is the best procedure for monitoring the therapeutic effect.2. I/Q is an effective method for the diagnosis and follow-up study of COPD. The aerosol inhalation imaging not only detects the respiratory function of the lungs but also localizes the site of obstruction of the respiratory tract.3.The first pass pulmonary perfusion imaging is the most sensitive and quantitative method for detecting minute pulmonary arteriovenous shut which is often not detectable by pulmonary angiography.4. Ga-67 imaging is valuable in the diagnosis of pulmonary sarcoidosis. Its use in detecting primary lung cancer is controversial, but this technique is helpful to assess mediastinal and hilar lymph node metastases.5. MCC and LEP studies are new modalities which help us to better understand pulmonary physiology. Smoking and certain respiratory diseases effect MCC function and LEP is increased in patients with interstitial lung diseases.