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Objectives: Multicentre evaluation of the precision of semi-automatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their inter-observer variability in multi-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., Key Points: • In a multicentre setting, semi-automatic measurements are more accurate than manual assessments. • Lymph node volumetry outperforms all other semi-automatically and manually performed measurements. • Use of semi-automatic lymph node analyses can reduce the inter-observer variability.

Objective: Quantification of tumour burden in oncology requires accurate and reproducible evaluation. The current standard is RECIST measurement with its inherent disadvantages. Volumetric analysis is an alternative for therapy monitoring. The aim of this study was to evaluate the feasibility of volumetric analysis of lymph node metastases using a software prototype in a follow-up setting., Methods: MSCT was performed in 50 patients covering the chest, abdomen and pelvis. A total of 174 suspicious lymph nodes were evaluated by two radiologists regarding short axis diameters and volumetric analysis using semi-automated software. Quality of segmentation, time, maximum diameter and volume were documented. Variability of the derived change rates was computed as the standard deviation of the difference of the obtained respective change rates., Results: The software performance provides robust volumetric analysis. Quality of segmentation was rated acceptable to excellent in 76-79% by each reader. Mean time spent per lesion was 38 s. The variability of change in effective diameters was 10.6%; for change rates of RECIST maximum diameter variability was 27.5%., Conclusion: Semi-automated volumetric analysis allows fast and convenient segmentation of most lymph node metastases. Compared with RECIST the inter-observer-variability in baseline and follow-up is reduced. This should principally allow subtle changes to be subclassified within the RECIST stable range as minor response [-15% to +10%].

To compare the image quality of dynamic lung MRI with variations of steady-state free-precession (SSFP) and gradient echo (GRE) cine techniques at 1.5 T and 3 T. Ventilated porcine lungs with simulated lesions inside a chest phantom and four healthy human subjects were assessed with SSFP (TR/TE=2.9/1.22 ms; 3 ima/s) and GRE sequences (TR/TE=2.34/0.96 ms; 8 ima/s) as baseline at 1.5 and 3 T. Modified SSFPs were performed with nine to ten images/s (parallel imaging factors 2 and 3). Image quality for representative structures and artifacts was ranked by three observers independently. At 1.5 T, standard SSFP achieved the best image quality with superior spatial resolution and signal, but equal temporal resolution to GRE. SSFP with improved temporal resolution was ranked second best. Further acceleration (PI factor 3) was of no benefit, but increased artifacts. At 3 T, GRE outranged SSFP imaging with high lesion signal intensity, while artifacts on SSFP images increased visibly. At 1.5 T, a modified SSFP with moderate parallel imaging (PI factor 2) was considered the best compromise of temporal and spatial resolution. At 3 T, GRE sequences remain the best choice for dynamic lung MRI.

Therapy monitoring in oncological patient care requires accurate and reliable imaging and post-processing methods. RECIST criteria are the current standard, with inherent disadvantages. The aim of this study was to investigate the feasibility of semi-automated volumetric analysis of lymph node metastases in patients with malignant melanoma compared to manual volumetric analysis and RECIST. Multislice CT was performed in 47 patients, covering the chest, abdomen and pelvis. In total, 227 suspicious, enlarged lymph nodes were evaluated retrospectively by two radiologists regarding diameters (RECIST), manually measured volume by placement of ROIs and semi-automated volumetric analysis. Volume (ml), quality of segmentation (++/--) and time effort (s) were evaluated in the study. The semi-automated volumetric analysis software tool was rated acceptable to excellent in 81% of all cases (reader 1) and 79% (reader 2). Median time for the entire segmentation process and necessary corrections was shorter with the semi-automated software than by manual segmentation. Bland-Altman plots showed a significantly lower interobserver variability for semi-automated volumetric than for RECIST measurements. The study demonstrated feasibility of volumetric analysis of lymph node metastases. The software allows a fast and robust segmentation in up to 80% of all cases. Ease of use and time needed are acceptable for application in the clinical routine. Variability and interuser bias were reduced to about one third of the values found for RECIST measurements.