Sayaka Watase1, Akinaga Sonoda2, Noritsugu Matsutani3, Shintarou Muraoka4, Jun Hanaoka5, Norihisa Nitta6, Yoshiyuki Watanabe7. 1. Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. Electronic address: smisaki@belle.shiga-med.ac.jp. 2. Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. Electronic address: akinaga@belle.shiga-med.ac.jp. 3. Healthcare Business Headquarters, Konica Minolta, Inc, 2970 Ishikawa-machi, Hachioji-shi, Tokyo, 192-8505, Japan. Electronic address: noritsugu.matsutani@konicaminolta.com. 4. Healthcare Business Headquarters, Konica Minolta, Inc, 2970 Ishikawa-machi, Hachioji-shi, Tokyo, 192-8505, Japan. Electronic address: shintarou.muraoka@konicaminolta.com. 5. Department of Thoracic Surgery, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. Electronic address: hanaoka@belle.shiga-med.ac.jp. 6. Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. Electronic address: r34nitta@belle.shiga-med.ac.jp. 7. Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan. Electronic address: ywatanab@belle.shiga-med.ac.jp.
Abstract
PURPOSE: Dynamic chest radiography (DCR) can observe the dynamic structure of the chest using continuous pulse fluoroscopy irradiation. However, its usefulness remains largely undetermined. The purpose of this study was to examine the relationship between changes in tracheal diameter during deep breathing and obstructive ventilation disorders using DCR. METHOD: Twelve participants with obstructive ventilatory impairment and 28 with normal pulmonary function underwent DCR during one cycle of deep inspiration and expiration. Three evaluators blinded to pulmonary function test results independently measured lateral diameters of the trachea in DCR images to determine whether there was a difference in the amount of change in tracheal diameter depending on the presence or absence of pulmonary dysfunction. Tracheal narrowing was defined as a decrease in the lateral tracheal diameter of more than 30 %. Participants were divided into a narrowing group and a non-narrowing group, and it was examined whether each group correlated with values of pulmonary function tests. RESULTS: Tracheal diameter was significantly narrowed in subjects with obstructive ventilatory impairment compared to normal subjects (P < 0.01). When subjects were divided into narrowing (tracheal narrowing rate [TNr] = 41.5 ± 7.7 %, n = 9) and non-narrowing groups (TNr = 9.1 ± 7.0 %, n = 31, p < 0.01), FEV1%-G, and %V25 were significantly smaller in the narrowing group than in the non-narrowing group (p < 0.01). CONCLUSIONS: Changes in tracheal diameter during deep breathing were easily evaluated using DCR. DCR may, therefore, be useful for evaluating obstructive ventilation disorders.
PURPOSE: Dynamic chest radiography (DCR) can observe the dynamic structure of the chest using continuous pulse fluoroscopy irradiation. However, its usefulness remains largely undetermined. The purpose of this study was to examine the relationship between changes in tracheal diameter during deep breathing and obstructive ventilation disorders using DCR. METHOD: Twelve participants with obstructive ventilatory impairment and 28 with normal pulmonary function underwent DCR during one cycle of deep inspiration and expiration. Three evaluators blinded to pulmonary function test results independently measured lateral diameters of the trachea in DCR images to determine whether there was a difference in the amount of change in tracheal diameter depending on the presence or absence of pulmonary dysfunction. Tracheal narrowing was defined as a decrease in the lateral tracheal diameter of more than 30 %. Participants were divided into a narrowing group and a non-narrowing group, and it was examined whether each group correlated with values of pulmonary function tests. RESULTS: Tracheal diameter was significantly narrowed in subjects with obstructive ventilatory impairment compared to normal subjects (P < 0.01). When subjects were divided into narrowing (tracheal narrowing rate [TNr] = 41.5 ± 7.7 %, n = 9) and non-narrowing groups (TNr = 9.1 ± 7.0 %, n = 31, p < 0.01), FEV1%-G, and %V25 were significantly smaller in the narrowing group than in the non-narrowing group (p < 0.01). CONCLUSIONS: Changes in tracheal diameter during deep breathing were easily evaluated using DCR. DCR may, therefore, be useful for evaluating obstructive ventilation disorders.