用较少的 CT 切片进行肺气肿定量的准确性。

Accuracy of emphysema quantification performed with reduced numbers of CT sections.

机构信息

Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd., Campus Box 8131, St. Louis, MO 63110, USA.

出版信息

AJR Am J Roentgenol. 2010 Mar;194(3):585-91. doi: 10.2214/AJR.09.2709.

DOI:10.2214/AJR.09.2709

PMID:20173132

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2838241/

Abstract

OBJECTIVE

The purpose of this study was to assess the accuracy of emphysema measurements obtained from systematic samples of evenly spaced CT images compared with measurements obtained from the entire scan.

MATERIALS AND METHODS

Evenly spaced transverse sections from the CT studies of 136 heavy smokers who underwent screening for lung cancer in the National Lung Screening Trial and of 112 subjects who underwent imaging before lung volume reduction surgery were sampled retrospectively. The samples were acquired both by selection of specific numbers of evenly spaced images and by selection of images at specific distance intervals. The percentage of lung pixels with attenuation below specific thresholds was used as an emphysema index. The image sample error was determined as the difference in emphysema index between the image samples and the entire scan.

RESULTS

The largest absolute image sample errors in the National Lung Screening Trial cohort with image sample sizes of five, 10, and 20 were 2.2, 0.8, and 0.5 index percentage points, respectively, at 1-mm section thickness (-960 HU threshold), and 2.6, 1.1, and 0.5 index percentage points at 5-mm section thickness (-930 HU threshold). The largest errors in the lung volume reduction surgery cohort for image sample sizes of five and 10 were 5.6 and 2.3 index percentage points at 8- to 10-mm section thickness (-900 HU threshold). Image sample errors were equivalent for the two sampling methods.

CONCLUSION

Systematic sampling resulted in very small errors in emphysema quantification and may be useful for decreasing radiation exposure in clinical research studies of emphysema.

摘要

目的

本研究旨在评估与整个扫描相比，从系统采集的等距 CT 图像中测量肺气肿的准确性。

材料与方法

回顾性采集了参加国家肺癌筛查试验的 136 名重度吸烟者和 112 名接受肺减容术前成像的患者 CT 研究的等距横断面。样本是通过选择特定数量的等距图像和选择特定距离间隔的图像来获取的。衰减低于特定阈值的肺像素百分比作为肺气肿指数。图像样本误差定义为图像样本与整个扫描之间肺气肿指数的差异。

结果

在 National Lung Screening Trial 队列中，使用 5、10 和 20 张图像的样本大小，在 1-mm 层厚（-960 HU 阈值）时，最大的绝对图像样本误差分别为 2.2、0.8 和 0.5 个指数百分比点，在 5-mm 层厚（-930 HU 阈值）时分别为 2.6、1.1 和 0.5 个指数百分比点。在肺减容手术队列中，使用 5 和 10 张图像的样本大小时，最大的图像样本误差分别为 5.6 和 2.3 个指数百分比点，在 8-10-mm 层厚（-900 HU 阈值）时。两种采样方法的图像样本误差相当。