Regional T1 relaxation time constants in Ex vivo human brain: Longitudinal effects of formalin exposure

Mekala R. Raman; Yunhong Shu; Timothy G. Lesnick; Clifford R. Jack; Kejal Kantarci

doi:10.1002/mrm.26140

Regional T₁ relaxation time constants in Ex vivo human brain: Longitudinal effects of formalin exposure

Mekala R. Raman, Yunhong Shu, Timothy G. Lesnick, Clifford R. Jack, Kejal Kantarci

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

Purpose: Relaxation time constants are useful as markers of tissue properties. Imaging ex vivo tissue is done for research purposes; however, T₁ relaxation time constants are altered by tissue fixation in a time-dependent manner. This study investigates regional changes in T₁ relaxation time constants in ex vivo brain tissue over 6 months of fixation. Methods: Five ex vivo human brain hemispheres in 10% formalin were scanned over 6 months. Mean T₁ relaxation time constants were measured in regions of interest (ROIs) representing gray matter (GM) and white matter (WM) regions and analyzed as a function of fixation time. Results: Cortical GM ROIs had longer T₁ relaxation time constants than WM ROIs; the thalamus had T₁ relaxation time constants similar to those of WM ROIs. T₁ relaxation time constants showed rapid shortening within the first 6 weeks after fixation followed by a slower rate of decline. Conclusion: Both GM and WM T₁ relaxation time constants of fixed brain tissue show rapid decline within the first 6 weeks after autopsy and slow by 6 months. This information is useful for optimizing MR imaging acquisition parameters according to fixation time for ex vivo brain imaging studies. Magn Reson Med 77:774–778, 2017.

Original language	English (US)
Pages (from-to)	774-778
Number of pages	5
Journal	Magnetic Resonance in Medicine
Volume	77
Issue number	2
DOIs	https://doi.org/10.1002/mrm.26140
State	Published - Feb 1 2017

Keywords

MRI
T1-mapping
brain
ex vivo
fixation
neuroimaging

ASJC Scopus subject areas

Radiology Nuclear Medicine and imaging

Access to Document

10.1002/mrm.26140

Cite this

@article{8efa7172122f4043a8ab75960799e21f,

title = "Regional T1 relaxation time constants in Ex vivo human brain: Longitudinal effects of formalin exposure",

abstract = "Purpose: Relaxation time constants are useful as markers of tissue properties. Imaging ex vivo tissue is done for research purposes; however, T1 relaxation time constants are altered by tissue fixation in a time-dependent manner. This study investigates regional changes in T1 relaxation time constants in ex vivo brain tissue over 6 months of fixation. Methods: Five ex vivo human brain hemispheres in 10% formalin were scanned over 6 months. Mean T1 relaxation time constants were measured in regions of interest (ROIs) representing gray matter (GM) and white matter (WM) regions and analyzed as a function of fixation time. Results: Cortical GM ROIs had longer T1 relaxation time constants than WM ROIs; the thalamus had T1 relaxation time constants similar to those of WM ROIs. T1 relaxation time constants showed rapid shortening within the first 6 weeks after fixation followed by a slower rate of decline. Conclusion: Both GM and WM T1 relaxation time constants of fixed brain tissue show rapid decline within the first 6 weeks after autopsy and slow by 6 months. This information is useful for optimizing MR imaging acquisition parameters according to fixation time for ex vivo brain imaging studies. Magn Reson Med 77:774–778, 2017.",

keywords = "MRI, T1-mapping, brain, ex vivo, fixation, neuroimaging",

author = "Raman, {Mekala R.} and Yunhong Shu and Lesnick, {Timothy G.} and Jack, {Clifford R.} and Kejal Kantarci",

note = "Publisher Copyright: {\textcopyright} 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine",

year = "2017",

month = feb,

day = "1",

doi = "10.1002/mrm.26140",

language = "English (US)",

volume = "77",

pages = "774--778",

journal = "Magnetic Resonance in Medicine",

issn = "0740-3194",

publisher = "John Wiley and Sons Inc.",

number = "2",

}

TY - JOUR

T1 - Regional T1 relaxation time constants in Ex vivo human brain

T2 - Longitudinal effects of formalin exposure

AU - Raman, Mekala R.

AU - Shu, Yunhong

AU - Lesnick, Timothy G.

AU - Jack, Clifford R.

AU - Kantarci, Kejal

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Purpose: Relaxation time constants are useful as markers of tissue properties. Imaging ex vivo tissue is done for research purposes; however, T1 relaxation time constants are altered by tissue fixation in a time-dependent manner. This study investigates regional changes in T1 relaxation time constants in ex vivo brain tissue over 6 months of fixation. Methods: Five ex vivo human brain hemispheres in 10% formalin were scanned over 6 months. Mean T1 relaxation time constants were measured in regions of interest (ROIs) representing gray matter (GM) and white matter (WM) regions and analyzed as a function of fixation time. Results: Cortical GM ROIs had longer T1 relaxation time constants than WM ROIs; the thalamus had T1 relaxation time constants similar to those of WM ROIs. T1 relaxation time constants showed rapid shortening within the first 6 weeks after fixation followed by a slower rate of decline. Conclusion: Both GM and WM T1 relaxation time constants of fixed brain tissue show rapid decline within the first 6 weeks after autopsy and slow by 6 months. This information is useful for optimizing MR imaging acquisition parameters according to fixation time for ex vivo brain imaging studies. Magn Reson Med 77:774–778, 2017.

AB - Purpose: Relaxation time constants are useful as markers of tissue properties. Imaging ex vivo tissue is done for research purposes; however, T1 relaxation time constants are altered by tissue fixation in a time-dependent manner. This study investigates regional changes in T1 relaxation time constants in ex vivo brain tissue over 6 months of fixation. Methods: Five ex vivo human brain hemispheres in 10% formalin were scanned over 6 months. Mean T1 relaxation time constants were measured in regions of interest (ROIs) representing gray matter (GM) and white matter (WM) regions and analyzed as a function of fixation time. Results: Cortical GM ROIs had longer T1 relaxation time constants than WM ROIs; the thalamus had T1 relaxation time constants similar to those of WM ROIs. T1 relaxation time constants showed rapid shortening within the first 6 weeks after fixation followed by a slower rate of decline. Conclusion: Both GM and WM T1 relaxation time constants of fixed brain tissue show rapid decline within the first 6 weeks after autopsy and slow by 6 months. This information is useful for optimizing MR imaging acquisition parameters according to fixation time for ex vivo brain imaging studies. Magn Reson Med 77:774–778, 2017.

KW - MRI

KW - T1-mapping

KW - brain

KW - ex vivo

KW - fixation

KW - neuroimaging

UR - http://www.scopus.com/inward/record.url?scp=84959431613&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84959431613&partnerID=8YFLogxK

U2 - 10.1002/mrm.26140

DO - 10.1002/mrm.26140

M3 - Article

C2 - 26888162

AN - SCOPUS:84959431613

SN - 0740-3194

VL - 77

SP - 774

EP - 778

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

IS - 2

ER -