Yoshitake Yamada1, Minoru Yamada2, Yoichi Yokoyama2, Akiko Tanabe3, Shiho Matsuoka3, Yuki Niijima4, Keiichi Narita2, Takehiro Nakahara2, Mitsuru Murata5, Koichi Fukunaga6, Shotaro Chubachi6, Masahiro Jinzaki2. 1. Department of Radiology, Keio University School of Medicine, Tokyo, Japan, yamada@rad.med.keio.ac.jp. 2. Department of Radiology, Keio University School of Medicine, Tokyo, Japan. 3. Department of Clinical Laboratory, Keio University Hospital, Tokyo, Japan. 4. Office of Radiation Technology, Keio University Hospital, Tokyo, Japan. 5. Department of Laboratory Medicine, Keio University School of Medicine, Tokyo, Japan. 6. Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
Abstract
BACKGROUND: No clinical studies to date have compared unilateral lung or lobe volumes between the supine and standing positions. OBJECTIVES: To compare lung/lobe volumes on computed tomography (CT) between these two positions and evaluate the correlation between the total lung volume and total lung capacity (TLC) on pulmonary function tests (PFTs). METHODS: Thirty-two asymptomatic volunteers underwent both conventional CT (supine position) and upright CT (standing position), during deep inspiration breath-hold, and PFTs on the same day. We measured lung/lobe volumes on CT in each position. Paired t tests were used for statistical analysis. RESULTS: The volumes of the total lung (10.9% increase), right lung (10.3% increase), right upper lobe (8.6% increase), right lower lobe (14.6% increase), left lung (11.6% increase), left upper lobe (7.1% increase), and left lower lobe (16.0% increase) were significantly greater in the standing position than in the supine position (all p < 0.0001). The right middle lobe volume was similar between the two positions (p = 0.16). Intraclass correlation coefficients for agreement between total lung volumes on CT in the supine/standing positions and the TLC on PFT were 0.891/0.938, respectively. CONCLUSIONS: While the volumes of the bilateral upper and lower lobes and bilateral lungs were significantly greater in the standing than in the supine position, with lower lobes showing larger changes, the right middle lobe volume did not change significantly between positions. The total lung volume on upright CT in the standing position was more similar to TLC on PFT than that in the supine position.
BACKGROUND: No clinical studies to date have compared unilateral lung or lobe volumes between the supine and standing positions. OBJECTIVES: To compare lung/lobe volumes on computed tomography (CT) between these two positions and evaluate the correlation between the total lung volume and total lung capacity (TLC) on pulmonary function tests (PFTs). METHODS: Thirty-two asymptomatic volunteers underwent both conventional CT (supine position) and upright CT (standing position), during deep inspiration breath-hold, and PFTs on the same day. We measured lung/lobe volumes on CT in each position. Paired t tests were used for statistical analysis. RESULTS: The volumes of the total lung (10.9% increase), right lung (10.3% increase), right upper lobe (8.6% increase), right lower lobe (14.6% increase), left lung (11.6% increase), left upper lobe (7.1% increase), and left lower lobe (16.0% increase) were significantly greater in the standing position than in the supine position (all p < 0.0001). The right middle lobe volume was similar between the two positions (p = 0.16). Intraclass correlation coefficients for agreement between total lung volumes on CT in the supine/standing positions and the TLC on PFT were 0.891/0.938, respectively. CONCLUSIONS: While the volumes of the bilateral upper and lower lobes and bilateral lungs were significantly greater in the standing than in the supine position, with lower lobes showing larger changes, the right middle lobe volume did not change significantly between positions. The total lung volume on upright CT in the standing position was more similar to TLC on PFT than that in the supine position.
Authors: Tim Fischer; Yassir El Baz; Giulia Scanferla; Nicole Graf; Frederike Waldeck; Gian-Reto Kleger; Thomas Frauenfelder; Jens Bremerich; Sabine Schmidt Kobbe; Jean-Luc Pagani; Sebastian Schindera; Anna Conen; Simon Wildermuth; Sebastian Leschka; Carol Strahm; Stephan Waelti; Tobias Johannes Dietrich; Werner C Albrich Journal: Eur J Radiol Open Date: 2022-06-24