2026-05-19 九州大学
図1）胸部X線動態撮影とは
単純 X 線撮影と同様の装置を用い、7-10 秒の息止め間に連続撮影する手法で、15 フレーム／秒の連続 X 線画像を取得します。
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1477
- https://pubs.rsna.org/doi/abs/10.1148/radiol.252344?journalCode=radiology
修復されたファロー四徴症における肺動脈弁逆流を評価するための新しい動的胸部X線撮影法 Novel Dynamic Chest Radiography Technique for Assessing Pulmonary Regurgitation in Repaired Tetralogy of Fallot
Yuzo Yamasaki, MD, PhD, Koji Sagiyama, MD, PhD, Tomoyuki Hida, MD, PhD, Takuya Hino, MD, PhD, Megumi Ikeda, MD, Kosuke Tabata, MD, Daisuke Toyomura, MD, … , and Kousei Ishigami, MD, PhD
Radiology Published:May 19 2026
DOI:https://doi.org/10.1148/radiol.252344
Abstract
Background
Cardiac MRI plays a key role in the assessment of pulmonary regurgitation (PR) after surgical repair of tetralogy of Fallot (TOF). However, its use may be limited by low availability, claustrophobia, or incompatible pacemakers or defibrillators.
Purpose
To evaluate the utility of dynamic chest radiography (DCR) for estimating PR after surgical TOF repair.
Materials and Methods
In this retrospective observational study, patients with repaired TOF who underwent DCR and phase-contrast cardiac MRI within 1 week between February 2018 and June 2024, and age- and sex-matched healthy volunteers, were enrolled. Temporal changes in pixel values of pulmonary arteries on DCR images were analyzed using specialized software. The maximum pixel value change (Max PV), maximum slope of pixel value change (Max PV Slope), and minimum slope of pixel value change (Min PV Slope) during a single cardiac cycle were calculated. Correlation between these indexes and PR fraction (PRF) at phase-contrast MRI and the ability of each index to differentiate severe PR (>30%) from nonsevere PR (≤30%) were assessed. Pearson correlation and receiver operating characteristic analyses were performed.
Results
The final study sample included 58 patients with repaired TOF (mean age, 30.6 years ± 10.3 [SD]; 29 [50%] male patients) and 14 healthy volunteers (mean age, 31.1 years ± 5.5; eight [57%] male individuals). Compared with patients with nonsevere PR and volunteers, patients with severe PR had the highest mean Max PV (severe PR: 26.2% ± 8.1; nonsevere PR: 14.1% ± 4.2; volunteers: 9.4% ± 3.0; P < .001), highest mean Max PV Slope (percentage change per frame) (severe PR: 6.6 ± 2.2; nonsevere PR: 2.9 ± 0.9; volunteers: 1.8 ± 0.6; P < .001), and lowest mean Min PV Slope (percentage change per frame) (severe PR: −7.2 ± 2.0; nonsevere PR: −4.6 ± 1.6; volunteers: −3.5 ± 1.4; P < .001). For patients with repaired TOF, all indexes were correlated with PRF; of these indexes, Max PV Slope had the highest correlation (R = 0.87; P < .001) and area under the receiver operating characteristic curve (0.98 [95% CI: 0.94, 1.0]; cutoff, 4.13%), yielding a sensitivity of 93% and specificity of 94%.
Conclusion
Max PV Slope from DCR showed high diagnostic value for PR severity in patients with repaired TOF.
