Value of formalin fixation for the prolonged preservation of rodent myocardial microanatomical organization: Evidence by MR diffusion tensor imaging.
File(s)
Accepted version
Author(s)
Giannakidis, A
Gullberg, GT
Pennell, DJ
Firmin, DN
Type
Journal Article
Abstract
Previous ex vivo diffusion tensor imaging (DTI) studies on formalin fixed myocardial tissue assumed that, after some initial changes in the first 48 hours since the start of fixation, DTI parameters remain stable over time. Prolonged preservation of cardiac tissue in formalin prior to imaging has been seen many times in the DTI literature as it is considered orderly. Our objective is to define the effects of the prolonged cardiac tissue exposure to formalin on tissue microanatomical organization, as this is assessed by DTI parameters. DTI experiments were conducted on eight excised rodent hearts that were fixed by immersion in formalin. The samples were randomly divided into two equinumerous groups corresponding to shorter (∼2 weeks) and more prolonged (∼ 6-8 weeks) durations of tissue exposure to formalin prior to imaging. We found that when the duration of cardiac tissue exposure to formalin before imaging increased, water diffusion became less restricted, helix angle (HA) histograms flattened out and exhibited heavier tails (even though the classic HA transmural variation was preserved), and a significant loss of inter-voxel primary diffusion orientation integrity was introduced. The prolonged preservation of cardiac tissue in formalin profoundly affected its microstructural organization, as this was assessed by DTI parameters. The accurate interpretation of diffusivity profiles necessitates awareness of the pitfalls of prolonged cardiac tissue exposure duration to formalin. The acquired knowledge works to the advantage of a proper experimental design of DTI studies of fixed hearts. This article is protected by copyright. All rights reserved.
Date Issued
2016-04-25
Date Acceptance
2016-03-14
Citation
Anatomical Record, 2016, 299 (7), pp.878-887
ISSN
0749-3002
Publisher
Wiley
Start Page
878
End Page
887
Journal / Book Title
Anatomical Record
Volume
299
Issue
7
Copyright Statement
This is the peer reviewed version of the following article: Giannakidis, A., Gullberg, G. T., Pennell, D. J. and Firmin, D. N. (2016), Value of Formalin Fixation for the Prolonged Preservation of Rodent Myocardial Microanatomical Organization: Evidence by MR Diffusion Tensor Imaging. Anat Rec, 299: 878–887, which has been published in final form at https://dx.doi.org/10.1002/ar.23359. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Sponsor
Wellcome Trust
Royal Brompton & Harefield NHS Foundation Trust
Grant Number
093953/Z/10/Z
WHCC_P45505
Subjects
Magnetic resonance diffusion tensor imaging
diffusion anisotropy
diffusivity
fixation
formalin
helix angle
inter-voxel diffusion coherence
rat myocardial microanatomy
Publication Status
Published