PURPOSE: Apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (DWI) may be of value in discriminating malignant from non-malignant lymph nodes, provided that they are reproducible. The aim of this study was to determine the inter- and intra-observer reproducibilities of ADC measurements of lymph nodes and to provide an overview of the current literature on ADC measurements in the characterization of lymph nodes. MATERIALS AND METHODS: Twenty healthy volunteers underwent DWI of the head and neck region and the pelvic region, at b-values of 0 and 1000 s/mm(2). Two observers independently and blindly measured ADCs of lymph nodes. Inter- and intra-observer reproducibilities were assessed using the Bland-Altman method. RESULTS: Mean ADCs of normal lymph nodes (in 10(-3)mm(2)/s) varied between 1.15 and 1.18. Ranges of mean ADC difference+/-limits of agreement (in 10(-3)mm(2)/s) for inter-observer agreement were -0.03 to 0.02+/-0.15 to 0.31. Ranges of mean ADC difference+/-limits of agreement (in 10(-3)mm(2)/s) for intra-observer agreement were 0.00 to 0.04+/-0.13 to 0.32. CONCLUSION: In conclusion, in light of previously reported data, the results of the present study suggest that ADC measurements may not always be sufficiently reproducible to discriminate malignant from non-malignant lymph nodes. Future studies which directly compare the ADCs of different nodal pathologies/conditions are required to further investigate the inter- and intra-observer reproducibilities of ADC measurements of lymph nodes. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.
PURPOSE: Apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (DWI) may be of value in discriminating malignant from non-malignant lymph nodes, provided that they are reproducible. The aim of this study was to determine the inter- and intra-observer reproducibilities of ADC measurements of lymph nodes and to provide an overview of the current literature on ADC measurements in the characterization of lymph nodes. MATERIALS AND METHODS: Twenty healthy volunteers underwent DWI of the head and neck region and the pelvic region, at b-values of 0 and 1000 s/mm(2). Two observers independently and blindly measured ADCs of lymph nodes. Inter- and intra-observer reproducibilities were assessed using the Bland-Altman method. RESULTS: Mean ADCs of normal lymph nodes (in 10(-3)mm(2)/s) varied between 1.15 and 1.18. Ranges of mean ADC difference+/-limits of agreement (in 10(-3)mm(2)/s) for inter-observer agreement were -0.03 to 0.02+/-0.15 to 0.31. Ranges of mean ADC difference+/-limits of agreement (in 10(-3)mm(2)/s) for intra-observer agreement were 0.00 to 0.04+/-0.13 to 0.32. CONCLUSION: In conclusion, in light of previously reported data, the results of the present study suggest that ADC measurements may not always be sufficiently reproducible to discriminate malignant from non-malignant lymph nodes. Future studies which directly compare the ADCs of different nodal pathologies/conditions are required to further investigate the inter- and intra-observer reproducibilities of ADC measurements of lymph nodes. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.
Authors: Katrijn Michielsen; Ignace Vergote; Katya Op de Beeck; Frederic Amant; Karin Leunen; Philippe Moerman; Christophe Deroose; Geert Souverijns; Steven Dymarkowski; Frederik De Keyzer; Vincent Vandecaveye Journal: Eur Radiol Date: 2013-12-11 Impact factor: 5.315