Mergo P J, Williams W F, Gonzalez-Rothi R, Gibson R, Ros P R, Staab E V, Helmberger T
Department of Radiology, University of Florida College of Medicine, Gainesville 32610, USA.
AJR Am J Roentgenol. 1998 May;170(5):1355-60. doi: 10.2214/ajr.170.5.9574615.
The purpose of this investigation was to quantitatively assess abnormally low attenuation of the lung by use of three-dimensional volumetric reconstructions from routine helical CT and to assess their correlation with pulmonary function tests.
Helical CT was performed in 100 patients in full inspiration. Examination was also performed in full expiration in 53 of these patients. Three-dimensional volumetric reconstructions were performed for total lung volumes at inspiration and at expiration, with a threshold of -896 H on inspiratory CT and -790 H on expiratory CT, to quantify emphysematous change. Correlation was made with pulmonary function tests in 79 patients.
CT volumetric assessments of abnormally low attenuation of the lung at inspiration and expiration had a high correlation (r2 = .84, p < or = .0001). In comparison with pulmonary function tests, both inspiratory low attenuation of the lung and expiratory low attenuation of the lung correlated well with the logarithm of the ratio of the forced expiratory volume in 1 sec (FEV1) to the forced vital capacity (r2 = .74, p < or = .0001 and r2 = .74, p < or = .0001, respectively) and with the percentage of predicted ratio of the FEV1 to the forced vital capacity (r2 = .69, p < or = .0001 and r2 = .69, p < or = .0001, respectively). Linear correlations were also seen with FEV1, residual volume, and forced residual capacity.
Three-dimensional volumetric reconstructions of hypoattenuating lung correlate well with pulmonary function tests. In addition, inspiratory and expiratory data are also correlative, suggesting that a dedicated expiratory examination is not needed. This easily obtainable information will prove useful for patients with obstructive lung disease from emphysema, providing a measure of pulmonary function status in this population.
本研究的目的是通过使用常规螺旋CT的三维容积重建技术对肺的异常低衰减进行定量评估，并评估其与肺功能测试的相关性。
对100例患者进行了全吸气状态下的螺旋CT检查。其中53例患者还进行了全呼气状态下的检查。对吸气和呼气时的全肺容积进行三维容积重建，吸气CT的阈值为-896 H，呼气CT的阈值为-790 H，以量化肺气肿改变。对79例患者进行了与肺功能测试的相关性分析。
吸气和呼气时肺异常低衰减的CT容积评估具有高度相关性（r2 = 0.84，p≤0.0001）。与肺功能测试相比，吸气时肺的低衰减和呼气时肺的低衰减均与1秒用力呼气容积（FEV1）与用力肺活量之比的对数具有良好的相关性（r2分别为0.74，p≤0.0001和r2 = 0.74，p≤0.0001），并与FEV1与用力肺活量预测比值的百分比具有相关性（r2分别为0.69，p≤0.0001和r2 = 0.69，p≤0.0001）。与FEV1、残气量和用力残气量也存在线性相关性。
肺低衰减的三维容积重建与肺功能测试具有良好的相关性。此外，吸气和呼气数据也具有相关性，这表明不需要专门的呼气检查。这些易于获得的信息将被证明对患有肺气肿的阻塞性肺病患者有用，可提供该人群肺功能状态的一种测量方法。
