Johannes Wessling MD, Presenter: Nothing to Disclose

Michael Puesken MD, Abstract Co-Author: Nothing to Disclose

Boris Buerke MD, Abstract Co-Author: Nothing to Disclose

Matthias Weckesser MD, PhD, Abstract Co-Author: Nothing to Disclose

Joachim Gerss, Abstract Co-Author: Nothing to Disclose

Walter Leonhard Heindel MD, Abstract Co-Author: Nothing to Disclose

To assess measurement accuracy and reproducibility of semi-automated metric and volumetric lymph node analysis in MSCT.

Whole body CT with i.v. contrast was performed in 112 patients. In total, 724 peripheral, abdominal and thoracic lymph nodes (6 to 38 mm mean size 14.5±5.1 mm) were evaluated independently by two radiologists manually and by use of semi-automated segmentation software. Long axis diameter (LAD), short axis diameter (SAD) and volume were obtained. Statistical analysis encompassed intra-class correlation coefficients (ICC) and Bland-Altman plots.

Automated segmentation without need for further correction was possible in 470 out of 724 lymph nodes (65%). ICC revealed high correlation coefficients between manual and semi-automatic measurements (r=0.72-0.81). Bland-Altman plots showed significantly (p<0.0001) lower interobserver variability for semi-automated SAD (1.2%, 95% CI:0.4-2.7%) and LAD (4.0%, 95% CI:2.5-5.5%) as compared to their manuell counterparts. Manual and semi-automatic measurements (intraobserver variability) were found significantly different (p<0.0001) with relative differences of 11.7% (95% CI:10.6-12.6%) for LAD and 14.3% (95% CI:12.9-15.6%) for SAD. Bland-Altman plot revealed a trend towards size overestimation for semi-automatic SAD and LAD.

Semi-automatic LAD, SAD and volume measurements in lymph nodes are precise in terms of reproducibility. Measurement accuracy revealed a trend towards size overestimations which requires verification of the semi-automated segmentation results.

This work suggests semi-automatic analysis to be reproducible for follow-up of lymph node target lesions in MSCT.

Wessling, J, Puesken, M, Buerke, B, Weckesser, M, Gerss, J, Heindel, W, Measurement Accuracy and Reproducibility of Semi-automated Metric and Volumetric Lymph Node Analysis in MSCT.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013031.html