PURPOSE: To evaluate the effect of formalin fixation on biexponential modeling of diffusion decay in prostate tissue. METHODS: Three whole prostate specimens were imaged unfixed immediately postsurgery, and again after formalin fixation. Diffusion-weighted imaging was performed over an extended range of b-values and a biexponential model fitted to the signal decay curves. RESULTS: Tissue fixation resulted in a 35%, 20%, and 20% reduction in mean apparent diffusion coefficient of the higher diffusivity fit component for the three organs, respectively, and a 64%, 57%, and 45% reduction in mean apparent diffusion coefficient of the lower diffusivity component. The mean signal fraction of the higher diffusivity component was increased by 23%, 5%, and 1%, respectively. The effect of fixation did not appear to vary according to tissue type or glandular zone. CONCLUSION: Formalin fixed tissue appears to provide a stable model for detailed investigation of the microscopic biophysical basis of diffusion phenomena observed in vivo. Diffusivity changes that result from fixation may provide information about the microscopic environments of the biexponential components.
PURPOSE: To evaluate the effect of formalin fixation on biexponential modeling of diffusion decay in prostate tissue. METHODS: Three whole prostate specimens were imaged unfixed immediately postsurgery, and again after formalin fixation. Diffusion-weighted imaging was performed over an extended range of b-values and a biexponential model fitted to the signal decay curves. RESULTS: Tissue fixation resulted in a 35%, 20%, and 20% reduction in mean apparent diffusion coefficient of the higher diffusivity fit component for the three organs, respectively, and a 64%, 57%, and 45% reduction in mean apparent diffusion coefficient of the lower diffusivity component. The mean signal fraction of the higher diffusivity component was increased by 23%, 5%, and 1%, respectively. The effect of fixation did not appear to vary according to tissue type or glandular zone. CONCLUSION:Formalin fixed tissue appears to provide a stable model for detailed investigation of the microscopic biophysical basis of diffusion phenomena observed in vivo. Diffusivity changes that result from fixation may provide information about the microscopic environments of the biexponential components.
Authors: Colleen Bailey; Bernard Siow; Eleftheria Panagiotaki; John H Hipwell; Thomy Mertzanidou; Julie Owen; Patrycja Gazinska; Sarah E Pinder; Daniel C Alexander; David J Hawkes Journal: NMR Biomed Date: 2016-12-21 Impact factor: 4.044
Authors: Colleen Bailey; Roger M Bourne; Bernard Siow; Edward W Johnston; Mrishta Brizmohun Appayya; Hayley Pye; Susan Heavey; Thomy Mertzanidou; Hayley Whitaker; Alex Freeman; Dominic Patel; Greg L Shaw; Ashwin Sridhar; David J Hawkes; Shonit Punwani; Daniel C Alexander; Eleftheria Panagiotaki Journal: NMR Biomed Date: 2019-02-19 Impact factor: 4.044