Mergo P J, Helmberger T, Didovic J, Cernigliaro J, Ros P R, Staab E V
Department of Radiology, University of Florida College of Medicine, Gainesville 32610, USA.
J Thorac Imaging. 1999 Apr;14(2):122-5. doi: 10.1097/00005382-199904000-00011.
The authors develop a method to accurately and easily estimate the volume of pleural effusions with computed tomography (CT). In 15 patients with either simple or loculated pleural effusions (14 right-sided and 11 left-sided), routine helical CT examinations of the thorax were obtained. Two experienced radiologists visually estimated the volume of the effusions. Three-dimensional reconstructions of the pleural effusions were performed from the helical CT examinations, and the volumes of the effusions were calculated. Effusion volumes were also estimated using the formula d2 x l (d = greatest depth of the effusion on a single CT image, l = greatest length of the effusion). The computer calculated the estimated volumes and they were then statistically compared. The coefficient of correlation between the estimation by measurement and calculated volumes of all effusions was 0.908 (p<0.0001) for the right side, and 0.849 for the left side (p<0.002). Excluding the loculated effusions, the coefficient of correlation was 0.969 for the right side and 0.949 for the left side (p<.001). The volume estimation by visual inspection was also correlated to the calculated volumes (0.84 on the left and 0.85 on the right, p<0.008), but resulted in a consistent overestimation by 300 ml to 500 ml. Although pleural effusion volumes can be estimated by visual inspection with good correlation, some overestimation is consistently seen. Use of the formula d2 x l readily enables estimation of pleural effusion volume from CT, from two simple measurements. This formula-based method of volume estimation provides an accurate and easily measured means of estimation that is readily obtained from routine CT of the chest.
作者开发了一种通过计算机断层扫描（CT）准确且轻松地估计胸腔积液量的方法。对15例患有单纯性或局限性胸腔积液的患者（右侧14例，左侧11例）进行了胸部常规螺旋CT检查。两位经验丰富的放射科医生通过视觉估计积液量。根据螺旋CT检查对胸腔积液进行三维重建，并计算积液量。还使用公式d2×l（d =单个CT图像上积液的最大深度，l =积液的最大长度）来估计积液量。计算机计算出估计体积，然后进行统计学比较。所有积液的测量估计值与计算体积之间的右侧相关系数为0.908（p<0.0001），左侧为0.849（p<0.002）。排除局限性积液后，右侧相关系数为0.969，左侧为0.949（p<0.001）。视觉检查的体积估计值也与计算体积相关（左侧为0.84，右侧为0.85，p<0.008），但始终高估300 ml至500 ml。尽管通过视觉检查可以很好地估计胸腔积液量且相关性良好，但始终会出现一些高估情况。使用公式d2×l可以通过两个简单测量值轻松地从CT估计胸腔积液量。这种基于公式的体积估计方法提供了一种准确且易于测量的估计方法，可从胸部常规CT中轻松获得。
