Michael A Antonacci1,2, Le Zhang2,3, Simone Degan4, Detlev Erdmann5, Rosa T Branca1,2. 1. Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 2. Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 3. Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 4. Center for Molecular and Biomolecular Imaging, Department of Radiology and Dermatology, Duke University, Durham, North Carolina. 5. Division of Plastic, Reconstructive, Maxillofacial and Oral Surgery, Duke University Medical Center, Durham, North Carolina.
Abstract
PURPOSE: Absolute MR temperature measurements are currently difficult because they require precalibration procedures specific for tissue types and conditions. Reference of the lipid-dissolved 129 Xe resonance frequency to temperature-insensitive methylene protons (rLDX) has been proposed to remove the effect of macro- and microscopic susceptibility gradients to obtain absolute temperature information. The scope of this work is to evaluate the rLDX chemical shift (CS) dependence on lipid composition to estimate the precision of absolute temperature measurements in lipids. METHODS: Neat triglycerides, vegetable oils, and samples of freshly excised human and rodent adipose tissue (AT) are prepared under 129 Xe atmosphere and studied using high-resolution NMR. The rLDX CS is measured as a function of temperature. 1 H spectra are also acquired and the consistency of methylene-referenced water proton and rLDX CS values are compared in human AT. RESULTS: Although rLDX CS shows a dependence on lipid composition, in human and rodent AT samples the rLDX shows consistent CS values with a similar temperature dependence (-0.2058 ± 0.0010) ppm/°C × T (°C) + (200.15 ± 0.03) ppm, enabling absolute temperature measurements with an accuracy of 0.3°C. Methylene-referenced water CS values present variations of up to 4°C, even under well-controlled conditions. CONCLUSIONS: The rLDX can be used to obtain accurate absolute temperature measurements in AT, opening new opportunities for hyperpolarized 129 Xe MR to measure tissue absolute temperature.
PURPOSE: Absolute MR temperature measurements are currently difficult because they require precalibration procedures specific for tissue types and conditions. Reference of the lipid-dissolved 129 Xe resonance frequency to temperature-insensitive methylene protons (rLDX) has been proposed to remove the effect of macro- and microscopic susceptibility gradients to obtain absolute temperature information. The scope of this work is to evaluate the rLDX chemical shift (CS) dependence on lipid composition to estimate the precision of absolute temperature measurements in lipids. METHODS: Neat triglycerides, vegetable oils, and samples of freshly excised human and rodent adipose tissue (AT) are prepared under 129 Xe atmosphere and studied using high-resolution NMR. The rLDX CS is measured as a function of temperature. 1 H spectra are also acquired and the consistency of methylene-referenced water proton and rLDX CS values are compared in human AT. RESULTS: Although rLDX CS shows a dependence on lipid composition, in human and rodent AT samples the rLDX shows consistent CS values with a similar temperature dependence (-0.2058 ± 0.0010) ppm/°C × T (°C) + (200.15 ± 0.03) ppm, enabling absolute temperature measurements with an accuracy of 0.3°C. Methylene-referenced waterCS values present variations of up to 4°C, even under well-controlled conditions. CONCLUSIONS: The rLDX can be used to obtain accurate absolute temperature measurements in AT, opening new opportunities for hyperpolarized 129 Xe MR to measure tissue absolute temperature.
Authors: K Kuroda; R V Mulkern; K Oshio; L P Panych; T Nakai; T Moriya; S Okuda; K Hynynen; F A Jolesz; F A Joles Journal: Magn Reson Med Date: 2000-02 Impact factor: 4.668
Authors: Paul Baron; Roel Deckers; Job G Bouwman; Chris J G Bakker; Martijn de Greef; Max A Viergever; Chrit T W Moonen; Lambertus W Bartels Journal: Magn Reson Med Date: 2015-05-02 Impact factor: 4.668
Authors: Le Zhang; Alex Burant; Andrew McCallister; Victor Zhao; Karl M Koshlap; Simone Degan; Michael Antonacci; Rosa Tamara Branca Journal: Magn Reson Med Date: 2016-10-19 Impact factor: 4.668
Authors: Michael A Antonacci; Christian McHugh; Michele Kelley; Andrew McCallister; Simone Degan; Rosa T Branca Journal: Sci Rep Date: 2019-10-16 Impact factor: 4.379