Harriet J Rogers1,2, Martijn V Verhagen3, Chris A Clark4, Patrick W Hales4. 1. Great Ormond Street Institute of Child Health, University College London, 30 Guilford St, Holborn, London, WC1N 1EH, UK. harriet.rogers@ucl.ac.uk. 2. Centre of Medical Imaging, Division of Medicine, University College London, 2nd Floor Charles Bell House, 43-45 Foley Street, London, W1W 7TS, UK. harriet.rogers@ucl.ac.uk. 3. Great Ormond Street Hospital, Great Ormond Street, London, WC1N 3JH, UK. 4. Great Ormond Street Institute of Child Health, University College London, 30 Guilford St, Holborn, London, WC1N 1EH, UK.
Abstract
OBJECTIVE: ADC (Apparent Diffusion Coefficient) derived from Diffusion-Weighted Imaging (DWI) has shown promise as a non-invasive quantitative imaging biomarker in Wilms' tumours. However, many non-Gaussian models could be applied to DWI. This study aimed to compare the suitability of four diffusion models (mono exponential, IVIM [Intravoxel Incoherent Motion], stretched exponential, and kurtosis) in Wilms' tumours and the unaffected contralateral kidneys. MATERIALS AND METHODS: DWI data were retrospectively reviewed (110 Wilms' tumours and 75 normal kidney datasets). The goodness of fit for each model was measured voxel-wise using Akaike Information Criteria (AIC). Mean AIC was calculated for each tumour volume (or contralateral normal kidney tissue). One-way ANOVAs with Greenhouse-Geisser correction and post hoc tests using the Bonferroni correction evaluated significant differences between AIC values; the lowest AIC indicating the optimum model. RESULTS: IVIM and stretched exponential provided the best fits to the Wilms' tumour DWI data. IVIM provided the best fit for the normal kidney data. Mono exponential was the least appropriate fitting method for both Wilms' tumour and normal kidney data. DISCUSSION: The diffusion weighted signal in Wilms' tumours and normal kidney tissue does not exhibit a mono-exponential decay and is better described by non-Gaussian models of diffusion.
OBJECTIVE: ADC (Apparent Diffusion Coefficient) derived from Diffusion-Weighted Imaging (DWI) has shown promise as a non-invasive quantitative imaging biomarker in Wilms' tumours. However, many non-Gaussian models could be applied to DWI. This study aimed to compare the suitability of four diffusion models (mono exponential, IVIM [Intravoxel Incoherent Motion], stretched exponential, and kurtosis) in Wilms' tumours and the unaffected contralateral kidneys. MATERIALS AND METHODS: DWI data were retrospectively reviewed (110 Wilms' tumours and 75 normal kidney datasets). The goodness of fit for each model was measured voxel-wise using Akaike Information Criteria (AIC). Mean AIC was calculated for each tumour volume (or contralateral normal kidney tissue). One-way ANOVAs with Greenhouse-Geisser correction and post hoc tests using the Bonferroni correction evaluated significant differences between AIC values; the lowest AIC indicating the optimum model. RESULTS: IVIM and stretched exponential provided the best fits to the Wilms' tumour DWI data. IVIM provided the best fit for the normal kidney data. Mono exponential was the least appropriate fitting method for both Wilms' tumour and normal kidney data. DISCUSSION: The diffusion weighted signal in Wilms' tumours and normal kidney tissue does not exhibit a mono-exponential decay and is better described by non-Gaussian models of diffusion.
Authors: Kevin M Bennett; Kathleen M Schmainda; Raoqiong Tong Bennett; Daniel B Rowe; Hanbing Lu; James S Hyde Journal: Magn Reson Med Date: 2003-10 Impact factor: 4.668
Authors: Patrick W Hales; Øystein E Olsen; Neil J Sebire; Kathy Pritchard-Jones; Chris A Clark Journal: NMR Biomed Date: 2015-06-09 Impact factor: 4.044
Authors: Harriet J Rogers; Martijn V Verhagen; Susan C Shelmerdine; Christopher A Clark; Patrick W Hales Journal: Eur Radiol Date: 2018-12-17 Impact factor: 5.315