Wada Noriaki, Tsunomori Akinori, Kubo Takeshi, Hino Takuya, Hata Akinori, Yamada Yoshitake, Ueyama Masako, Nishino Mizuki, Kurosaki Atsuko, Ishigami Kousei, Kudoh Shoji, Hatabu Hiroto
Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA.
R&D Promotion Division, Healthcare Business Headquarters, KONICA MINOLTA, INC., 2970 Ishikawa-machi, Hachioji-shi, Tokyo 192-8505, Japan.
Eur J Radiol Open. 2024 Jun 27;13:100579. doi: 10.1016/j.ejro.2024.100579. eCollection 2024 Dec.
To investigate the association of lung signal intensity changes during forced breathing using dynamic digital radiography (DDR) with pulmonary function and disease severity in patients with chronic obstructive pulmonary disease (COPD).
This retrospective study included 46 healthy subjects and 33 COPD patients who underwent posteroanterior chest DDR examination. We collected raw signal intensity and gray-scale image data. The lung contour was extracted on the gray-scale images using our previously developed automated lung field tracking system and calculated the average of signal intensity values within the extracted lung contour on gray-scale images. Lung signal intensity changes were quantified as SImax/SImin, representing the maximum ratio of the average signal intensity in the inspiratory phase to that in the expiratory phase. We investigated the correlation between SImax/SImin and pulmonary function parameters, and differences in SImax/SImin by disease severity.
SImax/SImin showed the highest correlation with VC (r = 0.54, P < 0.0001), followed by FEV (r = 0.44, P < 0.0001), both of which are key indicators of COPD pathophysiology. In a multivariate linear regression analysis adjusted for confounding factors, SImax/SImin was significantly lower in the severe COPD group compared to the normal group (P = 0.0004) and mild COPD group (P=0.0022), suggesting its potential usefulness in assessing COPD severity.
This study suggests that the signal intensity changes of lung fields during forced breathing using DDR reflect the pathophysiology of COPD and can be a useful index in assessing pulmonary function in COPD patients, potentially improving COPD diagnosis and management.
利用动态数字X线摄影（DDR）研究慢性阻塞性肺疾病（COPD）患者用力呼吸时肺信号强度变化与肺功能及疾病严重程度的相关性。
这项回顾性研究纳入了46名健康受试者和33名接受了胸部正位DDR检查的COPD患者。我们收集了原始信号强度和灰度图像数据。使用我们之前开发的自动肺野追踪系统在灰度图像上提取肺轮廓，并计算提取的肺轮廓内灰度图像上信号强度值的平均值。肺信号强度变化量化为SImax/SImin，代表吸气相平均信号强度与呼气相平均信号强度的最大比值。我们研究了SImax/SImin与肺功能参数之间的相关性，以及不同疾病严重程度下SImax/SImin的差异。
SImax/SImin与肺活量（VC）的相关性最高（r = 0.54，P < 0.0001），其次是第一秒用力呼气容积（FEV）（r = 0.44，P < 0.0001），这两者都是COPD病理生理学的关键指标。在对混杂因素进行校正的多变量线性回归分析中，重度COPD组的SImax/SImin显著低于正常组（P = 0.0004）和轻度COPD组（P = 0.0022），表明其在评估COPD严重程度方面具有潜在用途。
本研究表明，使用DDR测量的用力呼吸时肺野信号强度变化反映了COPD的病理生理学，并且可能是评估COPD患者肺功能的有用指标，有望改善COPD的诊断和管理。
