Hyperpolarized [1-(13) C]pyruvate MRI for noninvasive examination of placental metabolism and nutrient transport: A feasibility study in pregnant guinea pigs

Lanette J Friesen-Waldner; Kevin J Sinclair; Trevor P Wade; Banoub Michael; Albert P Chen; Barbra de Vrijer; Timothy R H Regnault; Charles A McKenzie

doi:10.1002/jmri.25009

Hyperpolarized [1-(13) C]pyruvate MRI for noninvasive examination of placental metabolism and nutrient transport: A feasibility study in pregnant guinea pigs

J Magn Reson Imaging. 2016 Mar;43(3):750-5. doi: 10.1002/jmri.25009. Epub 2015 Jul 31.

Authors

Lanette J Friesen-Waldner¹, Kevin J Sinclair¹, Trevor P Wade^{1

2}, Banoub Michael¹, Albert P Chen³, Barbra de Vrijer^{4

5

6}, Timothy R H Regnault^{4

5

6

7}, Charles A McKenzie^{1

2

5

6}

Affiliations

¹ Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
² Robarts Research Institute, University of Western Ontario, London, Ontario, Canada.
³ GE Healthcare, Toronto, Ontario, Canada.
⁴ Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario, Canada.
⁵ Children's Health Research Institute, London, Ontario, Canada.
⁶ Lawson Research Institute, London, Ontario, Canada.
⁷ Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.

PMID: 26227963
DOI: 10.1002/jmri.25009

Abstract

Purpose: To test the feasibility of hyperpolarized [1-(13) C]pyruvate magnetic resonance imaging (MRI) for noninvasive examination of guinea pig fetoplacental metabolism and nutrient transport.

Materials and methods: Seven pregnant guinea pigs with a total of 30 placentae and fetuses were anesthetized and scanned at 3T. T1 -weighted (1) H images were obtained from the maternal abdomen. An 80 mM solution of hyperpolarized [1-(13) C]pyruvate (hereafter referred to as pyruvate) was injected into a vein in the maternal foot. Time-resolved 3D (13) C images were acquired starting 10 seconds after the beginning of bolus injection and every 10 seconds after to 50 seconds. The pregnant guinea pigs were recovered after imaging. Regions of interest (ROIs) were drawn around the maternal heart and each placenta and fetal liver in all slices in the (1) H images. These ROIs were copied to the (13) C images and were used to calculate the sum of the pyruvate and lactate signal intensities for each organ. The signal intensities were normalized by the volume of the organ and the maximum signal in the maternal heart.

Results: No adverse events were observed in the pregnant guinea pigs and natural pupping occurred at term (∼68 days). Pyruvate signal was observed in all 30 placentae, and lactate, a by-product of pyruvate metabolism, was also observed in all placentae. The maximum pyruvate and lactate signals in placentae occurred at 20 seconds. In addition to the observation of pyruvate and lactate signals in the placentae, both pyruvate and lactate signals were observed in all fetal livers. The maximum pyruvate and lactate signals in the fetal livers occurred at 10 seconds and 20 seconds, respectively.

Conclusion: This work demonstrates the feasibility of using hyperpolarized [1-(13) C]pyruvate MRI to noninvasively examine fetoplacental metabolism and transport of pyruvate in guinea pigs. Hyperpolarized (13) C MRI may provide a novel method for longitudinal studies of fetoplacental abnormalities.

Keywords: fetus; hyperpolarized carbon-13; magnetic resonance imaging; metabolism; nutrient transport; placenta.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Feasibility Studies
Female
Fetus / diagnostic imaging
Guinea Pigs
Imaging, Three-Dimensional
Lactic Acid / chemistry
Magnetic Resonance Imaging*
Placenta / diagnostic imaging*
Placenta / metabolism
Pregnancy
Pyruvic Acid / chemistry*
Signal Processing, Computer-Assisted

Substances

Lactic Acid
Pyruvic Acid

Grants and funding

MOP-209113/Canadian Institutes of Health Research/Canada