The alveolar permeability in patients with diffuse infiltrative lung disease detected by Tc-99m DTPA radioaerosol inhalation lung scintigraphy and the relationships with the pulmonary function test.

BACKGROUND

In recent years, there has been growing interest in determining the solute exchange across the pulmonary epithelium for various diseases. Alveolar permeability (AP) in patients with diffuse infiltrative lung disease (ILD) was investigated in an attempt to correlate it with parameters of the Pulmonary Function Test.

METHODS

AP in 21 patients with ILD was measured by Tc-99m DTPA radioaerosol inhalation lung scintigraphy (DTPA). The degree of AP damage in ILD was presented as the slope (%/min) of the time-activity curve of the dynamic lung images. The AP of ILD patients was compared with the AP of 20 normal controls. Comprehensive pulmonary function tests, including forced expiratory volume, flow-volume loop, and diffusion capacity by the single breath CO method, were performed for comparison.

RESULTS

This study showed that there were (1) statistically significant differences among normal controls and patients with ILD and (2) no correlation for the slopes and parameters of pulmonary function tests. The patients were divided into two groups: (A) 8 ILD patients with normal chest X-ray and (B) 13 ILD patients with abnormal chest X-ray findings. There were no significant differences in the results of DTPA for groups (A) and (B).

CONCLUSIONS

When the AP of ILD patients is significantly damaged, however, the severity of the damage is not related to chest X-ray findings. Radionuclide alveolar permeability study is not related to traditional pulmonary function tests. The radionuclide alveolar permeability study should be used as a new method to evaluate lung function.