Comparison of manual and semi-automatic measuring techniques in MSCT scans of patients with lymphoma : a multicentre study

Abstract

Objectives Multicentre evaluation of the precision of semiautomatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their interobserver variability inmulti-slice CT (MSCT) of patients with lymphoma.Methods MSCT data of 63 patients were interpreted before and after chemotherapy by one/two radiologists in five university hospitals. In 307 lymph nodes, short (SAD)/long (LAD) axis diameter and WHO area were determined manually and semi-automatically. Volume was solely calculated semi-automatically. To determine the precision of the individual parameters, a mean was calculated for every lymph node/parameter. Deviation of the measured parameters from this mean was evaluated separately. Statistical analysis entailed intraclass correlation coefficients (ICC) and Kruskal–Wallis tests. Results Median relative deviations of semi-automatic parameters were smaller than deviations of manually assessed parameters, e.g. semi-automatic SAD 5.3 vs. manual 6.5 %. Median variations among different study sites were smaller if the measurement was conducted semi-automatically, e. g. manual LAD 5.7/4.2 % vs. semi-automatic 3.4/3.4 %. Semi-automatic volumetry was superior to the other parameters (2.8 %). Conclusions Semi-automatic determination of different lymph node parameters is (compared to manually assessed parameters) associated with a slightly greater precision and a marginally lower inter-observer variability. These results are with regard to the increasing mobility of patients among different medical centres and in relation to the quality management of multicentre trials of importance.