Subjects and Methods

The study included 192 patients with interstitial pneumonia who underwent inspiration and expiration on the same day by 80 rows or 16rows CT. The lung field density changes on the mediastinal side during inspiration and expiration were compared between CIFs and IIFs. The density of 1.5 cm diameter on the upper lobes of the mediastinal side was classified as high-density if higher than the lower lobes and as iso-density if equivalent. A significance test was performed to assess the changes in density.

Results [Fig. 1, 2, 3, 4, and 5]

Figure 1 presents the overall results. In the right lung, there were 63 cases of CIF and 129 cases of IIF, while in the left lung, there were 108 cases of CIF and 84 cases of IIF. The lung field density in the high and iso regions near the interlobar fissure of the bilateral upper lobes during inspiration and expiration, respectively, was examined. The number of cases in which the iso-density on inspiration shifted to high-density on expiration was counted in the same case.

In the CIF of the right lung, 34 of the 57 cases that were iso-density on inspiration shifted to high-density on expiration. In the IIF of the right lung, 35 of the 128 patients who were iso-density on inspiration exhibited high-density on expiration. The results were subjected to a chi-square test, as shown in Table 1, and a significant difference was found in the right lung at p=0.006.

In the CIF of the left lung, 77 of the 100 cases that were iso-density on inspiration shifted to high-density on expiration. In the IIF of the left lung, 32 of the 82 patients who were iso-density on inspiration exhibited a shift to high-density on expiration. The results were subjected to a chi-square test, as shown in Table 1, and a significant difference was found in the left lung at p=0.008.