Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR)

Research output: Contribution to conferenceAbstract

Abstract

Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR) Yutthapong Tongpob1,2, Alexander Joos3, Caitlin Wyrwoll1, and Kirk Feindel3,4 1 School of Human Sciences, The University of Western Australia, Perth, Australia, 2 Faculty of Medical Sciences, Naresuan University, Thailand, 3 Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Australia, 4 School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia A key driver of FGR is placental insufficiency, including inadequate development of placental vasculature. However, there are currently limitations in assessing placental function in-vivo. MRI can measure relaxation time (T2*), which correlates with oxygenation via alterations in blood haemoglobin saturation. Results of previous placental T2* studies have been conflicting, due to technical and analytical challenges, including consideration of only 2D regions of interest (ROI). This study utilised a 3D-MRI approach in a rat model of FGR. Time-mated rats were treated with either vehicle (Veh) or dexamethasone (Dex; 0.5μg/ml) in drinking water from embryonic day (E)13 onwards. Serial scans at E15, E18, and E21 were conducted using a 9.4T MRI in-vivo: a 3D-multi-gradient-echo sequence with oxygen challenge (oxygen vs medical-air) to obtain 3D-maps of the T2* signal. E21 dams were euthanised, feto-placental units dissected, and weighed. E21 T2*-values were calculated for manually defined 3D-ROIs with custom-Matlab software using the SQEXP algorithm, which is better suited for low signal to noise data than standard algorithms. In a separate cohort of rats, feto-placental vascular casts were generated, scanned using micro-CT and quantified with custom-Matlab software. E21 fetal and placental weights decreased in Dex rats by 15.6% and 35.2% respectively in comparison to Veh (p<0.0002). MRI scans revealed that when shifting from oxygen to medical-air, mean whole-placental T2* decreased in Veh and Dex by 35.2% and 20.9% respectively (p<0.05). Importantly, the relative shift in whole-placental T2* differed significantly between Veh and Dex (3.1+0.4 vs 2.0+0.5 msec; p<0.05), indicating reduced blood oxygenation in Dex placentas. Furthermore, the MRI measures aligned with a marked decline in feto-placental vascular complexity in Dex. Ongoing analyses are determining whether these changes are dynamic across gestation. The results of this proof-of-concept study demonstrate that T2*-based measurements of the placental blood oxygenation can provide non-invasive assessments of in-vivo placental health.
Original languageEnglish
Publication statusPublished - 19 Aug 2019
Event2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA) - International Convention Centre, Sydney, Sydney, Australia
Duration: 18 Aug 201921 Aug 2019
http://esa-srb.org.au

Conference

Conference2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA)
Abbreviated titleESA-SRB-AOTA 2019
CountryAustralia
CitySydney
Period18/08/1921/08/19
Internet address

Fingerprint

Fetal Development
Magnetic Resonance Imaging
Western Australia
Oxygen
Blood Vessels
Software
Air
Placental Insufficiency
Placentation
Medical Faculties
Fetal Weight
Thailand
Drinking Water
Placenta
Dexamethasone
Noise
Microscopy
Hemoglobins
Pregnancy
Health

Cite this

Tongpob, Y., Joos, A., & Feindel, K. (2019). Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR). Abstract from 2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), Sydney, Australia.
Tongpob, Yutthapong ; Joos, Alexander ; Feindel, Kirk. / Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR). Abstract from 2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), Sydney, Australia.
@conference{1545bf0329884538b482968f33df7cb6,
title = "Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR)",
abstract = "Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR) Yutthapong Tongpob1,2, Alexander Joos3, Caitlin Wyrwoll1, and Kirk Feindel3,4 1 School of Human Sciences, The University of Western Australia, Perth, Australia, 2 Faculty of Medical Sciences, Naresuan University, Thailand, 3 Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Australia, 4 School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia A key driver of FGR is placental insufficiency, including inadequate development of placental vasculature. However, there are currently limitations in assessing placental function in-vivo. MRI can measure relaxation time (T2*), which correlates with oxygenation via alterations in blood haemoglobin saturation. Results of previous placental T2* studies have been conflicting, due to technical and analytical challenges, including consideration of only 2D regions of interest (ROI). This study utilised a 3D-MRI approach in a rat model of FGR. Time-mated rats were treated with either vehicle (Veh) or dexamethasone (Dex; 0.5μg/ml) in drinking water from embryonic day (E)13 onwards. Serial scans at E15, E18, and E21 were conducted using a 9.4T MRI in-vivo: a 3D-multi-gradient-echo sequence with oxygen challenge (oxygen vs medical-air) to obtain 3D-maps of the T2* signal. E21 dams were euthanised, feto-placental units dissected, and weighed. E21 T2*-values were calculated for manually defined 3D-ROIs with custom-Matlab software using the SQEXP algorithm, which is better suited for low signal to noise data than standard algorithms. In a separate cohort of rats, feto-placental vascular casts were generated, scanned using micro-CT and quantified with custom-Matlab software. E21 fetal and placental weights decreased in Dex rats by 15.6{\%} and 35.2{\%} respectively in comparison to Veh (p<0.0002). MRI scans revealed that when shifting from oxygen to medical-air, mean whole-placental T2* decreased in Veh and Dex by 35.2{\%} and 20.9{\%} respectively (p<0.05). Importantly, the relative shift in whole-placental T2* differed significantly between Veh and Dex (3.1+0.4 vs 2.0+0.5 msec; p<0.05), indicating reduced blood oxygenation in Dex placentas. Furthermore, the MRI measures aligned with a marked decline in feto-placental vascular complexity in Dex. Ongoing analyses are determining whether these changes are dynamic across gestation. The results of this proof-of-concept study demonstrate that T2*-based measurements of the placental blood oxygenation can provide non-invasive assessments of in-vivo placental health.",
author = "Yutthapong Tongpob and Alexander Joos and Kirk Feindel",
year = "2019",
month = "8",
day = "19",
language = "English",
note = "2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), ESA-SRB-AOTA 2019 ; Conference date: 18-08-2019 Through 21-08-2019",
url = "http://esa-srb.org.au",

}

Tongpob, Y, Joos, A & Feindel, K 2019, 'Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR)' 2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), Sydney, Australia, 18/08/19 - 21/08/19, .

Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR). / Tongpob, Yutthapong; Joos, Alexander; Feindel, Kirk.

2019. Abstract from 2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), Sydney, Australia.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR)

AU - Tongpob, Yutthapong

AU - Joos, Alexander

AU - Feindel, Kirk

PY - 2019/8/19

Y1 - 2019/8/19

N2 - Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR) Yutthapong Tongpob1,2, Alexander Joos3, Caitlin Wyrwoll1, and Kirk Feindel3,4 1 School of Human Sciences, The University of Western Australia, Perth, Australia, 2 Faculty of Medical Sciences, Naresuan University, Thailand, 3 Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Australia, 4 School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia A key driver of FGR is placental insufficiency, including inadequate development of placental vasculature. However, there are currently limitations in assessing placental function in-vivo. MRI can measure relaxation time (T2*), which correlates with oxygenation via alterations in blood haemoglobin saturation. Results of previous placental T2* studies have been conflicting, due to technical and analytical challenges, including consideration of only 2D regions of interest (ROI). This study utilised a 3D-MRI approach in a rat model of FGR. Time-mated rats were treated with either vehicle (Veh) or dexamethasone (Dex; 0.5μg/ml) in drinking water from embryonic day (E)13 onwards. Serial scans at E15, E18, and E21 were conducted using a 9.4T MRI in-vivo: a 3D-multi-gradient-echo sequence with oxygen challenge (oxygen vs medical-air) to obtain 3D-maps of the T2* signal. E21 dams were euthanised, feto-placental units dissected, and weighed. E21 T2*-values were calculated for manually defined 3D-ROIs with custom-Matlab software using the SQEXP algorithm, which is better suited for low signal to noise data than standard algorithms. In a separate cohort of rats, feto-placental vascular casts were generated, scanned using micro-CT and quantified with custom-Matlab software. E21 fetal and placental weights decreased in Dex rats by 15.6% and 35.2% respectively in comparison to Veh (p<0.0002). MRI scans revealed that when shifting from oxygen to medical-air, mean whole-placental T2* decreased in Veh and Dex by 35.2% and 20.9% respectively (p<0.05). Importantly, the relative shift in whole-placental T2* differed significantly between Veh and Dex (3.1+0.4 vs 2.0+0.5 msec; p<0.05), indicating reduced blood oxygenation in Dex placentas. Furthermore, the MRI measures aligned with a marked decline in feto-placental vascular complexity in Dex. Ongoing analyses are determining whether these changes are dynamic across gestation. The results of this proof-of-concept study demonstrate that T2*-based measurements of the placental blood oxygenation can provide non-invasive assessments of in-vivo placental health.

AB - Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR) Yutthapong Tongpob1,2, Alexander Joos3, Caitlin Wyrwoll1, and Kirk Feindel3,4 1 School of Human Sciences, The University of Western Australia, Perth, Australia, 2 Faculty of Medical Sciences, Naresuan University, Thailand, 3 Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Australia, 4 School of Biomedical Sciences, The University of Western Australia, Perth, WA 6009, Australia A key driver of FGR is placental insufficiency, including inadequate development of placental vasculature. However, there are currently limitations in assessing placental function in-vivo. MRI can measure relaxation time (T2*), which correlates with oxygenation via alterations in blood haemoglobin saturation. Results of previous placental T2* studies have been conflicting, due to technical and analytical challenges, including consideration of only 2D regions of interest (ROI). This study utilised a 3D-MRI approach in a rat model of FGR. Time-mated rats were treated with either vehicle (Veh) or dexamethasone (Dex; 0.5μg/ml) in drinking water from embryonic day (E)13 onwards. Serial scans at E15, E18, and E21 were conducted using a 9.4T MRI in-vivo: a 3D-multi-gradient-echo sequence with oxygen challenge (oxygen vs medical-air) to obtain 3D-maps of the T2* signal. E21 dams were euthanised, feto-placental units dissected, and weighed. E21 T2*-values were calculated for manually defined 3D-ROIs with custom-Matlab software using the SQEXP algorithm, which is better suited for low signal to noise data than standard algorithms. In a separate cohort of rats, feto-placental vascular casts were generated, scanned using micro-CT and quantified with custom-Matlab software. E21 fetal and placental weights decreased in Dex rats by 15.6% and 35.2% respectively in comparison to Veh (p<0.0002). MRI scans revealed that when shifting from oxygen to medical-air, mean whole-placental T2* decreased in Veh and Dex by 35.2% and 20.9% respectively (p<0.05). Importantly, the relative shift in whole-placental T2* differed significantly between Veh and Dex (3.1+0.4 vs 2.0+0.5 msec; p<0.05), indicating reduced blood oxygenation in Dex placentas. Furthermore, the MRI measures aligned with a marked decline in feto-placental vascular complexity in Dex. Ongoing analyses are determining whether these changes are dynamic across gestation. The results of this proof-of-concept study demonstrate that T2*-based measurements of the placental blood oxygenation can provide non-invasive assessments of in-vivo placental health.

UR - http://esa-srb.org.au/interactive-program/

M3 - Abstract

ER -

Tongpob Y, Joos A, Feindel K. Detection of reduced oxygenation in 3D placental volumes by magnetic resonance imaging (MRI) in a rat model of fetal growth restriction (FGR). 2019. Abstract from 2019 Annual Scientific Meeting of the Endocrine Society of Australia (ESA), the Society for Reproductive Biology (SRB), and the Asia and Oceania Thyroid Association (AOTA), Sydney, Australia.