Wormanns Dag, Kohl Gerhard, Klotz Ernst, Marheine Anke, Beyer Florian, Heindel Walter, Diederich Stefan
Department of Clinical Radiology, University of Muenster, Albert-Schweitzer-Strasse 33, 48149, Muenster, Germany.
Eur Radiol. 2004 Jan;14(1):86-92. doi: 10.1007/s00330-003-2132-0. Epub 2003 Nov 13.
The aim of this study was to assess the in vivo measurement precision of a software tool for volumetric analysis of pulmonary nodules from two consecutive low-dose multi-row detector CT scans. A total of 151 pulmonary nodules (diameter 2.2-20.5 mm, mean diameter 7.4+/-4.5 mm) in ten subjects with pulmonary metastases were examined with low-dose four-detector-row CT (120 kVp, 20 mAs (effective), collimation 4x1 mm, normalized pitch 1.75, slice thickness 1.25 mm, reconstruction increment 0.8 mm; Somatom VolumeZoom, Siemens). Two consecutive low-dose scans covering the whole lung were performed within 10 min. Nodule volume was determined for all pulmonary nodules visually detected in both scans using the volumetry tool included in the Siemens LungCare software. The 95% limits of agreement between nodule volume measurements on different scans were calculated using the Bland and Altman method for assessing measurement agreement. Intra- and interobserver agreement of volume measurement were determined using repetitive measurements of 50 randomly selected nodules at the same scan by the same and different observers. Taking into account all 151 nodules, 95% limits of agreement were -20.4 to 21.9% (standard error 1.5%); they were -19.3 to 20.4% (standard error 1.7%) for 105 nodules <10 mm. Limits of agreement were -3.9 to 5.7% for intraobserver and -5.5 to 6.6% for interobserver agreement. Precision of in vivo volumetric analysis of nodules with an automatic volumetry software tool was sufficiently high to allow for detection of clinically relevant growth in small pulmonary nodules.
本研究的目的是评估一种软件工具对连续两次低剂量多排探测器CT扫描的肺结节进行容积分析的体内测量精度。对10例有肺转移的受试者中的151个肺结节（直径2.2 - 20.5mm，平均直径7.4±4.5mm）进行了低剂量四排探测器CT检查（120kVp，20mAs（有效），准直4×1mm，归一化螺距1.75，层厚1.25mm，重建增量0.8mm；西门子Somatom VolumeZoom）。在10分钟内进行了两次覆盖全肺的连续低剂量扫描。使用西门子LungCare软件中包含的容积测量工具，对两次扫描中肉眼检测到的所有肺结节确定其体积。采用Bland和Altman方法计算不同扫描上结节体积测量值之间的95%一致性界限，以评估测量一致性。通过同一观察者和不同观察者在同一次扫描中对50个随机选择的结节进行重复测量，确定观察者内和观察者间体积测量的一致性。考虑所有151个结节，95%一致性界限为-20.4%至21.9%（标准误1.5%）；对于105个直径<10mm的结节，95%一致性界限为-19.3%至{20.4%（标准误1.7%）。观察者内一致性界限为-3.9%至5.7%，观察者间一致性界限为-5.5%至6.6%。使用自动容积测量软件工具对结节进行体内容积分析的精度足够高，能够检测出小肺结节临床上相关的生长情况。
