Nishino Mizuki, Roberts David H, Sitek Arkadiusz, Raptopoulos Vassilios, Boiselle Phillip M, Hatabu Hiroto
Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
Acad Radiol. 2006 May;13(5):589-97. doi: 10.1016/j.acra.2005.10.025.
Since the initial description of an intralobar attenuation gradient by Webb et al, it has been suggested that departure from the intralobar attenuation gradient could indicate early lung diseases. However, its significance has not been determined in detail. We aimed to quantify the anteroposterior intralobar attenuation gradient on volumetric end-inspiratory and end-expiratory high-resolution computed tomography (CT) in patients with emphysema and to correlate the gradient values with pulmonary function.
The study population consisted of 21 consecutive patients with emphysema evaluated with volumetric expiratory high-resolution CT and 6 patients with normal high-resolution CT findings. The anteroposterior intralobar attenuation gradient values were quantified on end-inspiratory and end-expiratory sagittal reformations using a lung analysis software program and were correlated with pulmonary function tests results.
The intralobar attenuation gradient values in patients with forced expiratory volume in 1 second (FEV1) < or =70% were significantly smaller compared with those in patients with FEV1 >70% in bilateral lower lobes at end-expiration (P = .0061, P = .047, respectively, unpaired t-test). The FEV1 values in patients with attenuation gradient values < or =0.02 were significantly lower than in those with attenuation gradient values >0.02 (right lower lobe: P = .024; left lower lobe: P = .0034; chi-squared test). The intralobar attenuation gradient values in bilateral lower lobes at end-expiration were significantly correlated with FEV1 and FEV1/forced vital capacity (right: P = .031, P = .039, respectively; left: P = .036, P = .030, respectively, Pearson correlation).
The quantitative measurement of the anteroposterior intralobar attenuation gradient values of the lung showed that these gradients at end-expiration in both lower lobes correlate with obstructive physiology.
自Webb等人首次描述叶内衰减梯度以来，有人提出偏离叶内衰减梯度可能提示早期肺部疾病。然而，其意义尚未得到详细确定。我们旨在对肺气肿患者在吸气末和呼气末容积高分辨率计算机断层扫描（CT）上的前后叶内衰减梯度进行量化，并将梯度值与肺功能相关联。
研究人群包括21例连续接受容积呼气高分辨率CT评估的肺气肿患者和6例高分辨率CT结果正常的患者。使用肺部分析软件程序在吸气末和呼气末矢状位重建上对前后叶内衰减梯度值进行量化，并与肺功能测试结果相关联。
在呼气末，1秒用力呼气容积（FEV1）≤70%的患者双侧下叶叶内衰减梯度值明显小于FEV1>70%的患者（分别为P = 0.0061，P = 0.047，未配对t检验）。衰减梯度值≤0.02的患者的FEV1值明显低于衰减梯度值>0.02的患者（右下叶：P = 0.024；左下叶：P = 0.0034；卡方检验）。呼气末双侧下叶的叶内衰减梯度值与FEV1和FEV1/用力肺活量显著相关（右侧：分别为P = 0.031和P = 0.039；左侧：分别为P = 0.036和P = 0.030，Pearson相关性）。
肺前后叶内衰减梯度值的定量测量表明，呼气末两下叶的这些梯度与阻塞性生理相关。
