Yuhan Ma1, Avery J L Berman1,2, G Bruce Pike2. 1. McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada. 2. Department of Radiology and Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
Abstract
PURPOSE: To determine the contribution of paramagnetic dissolved oxygen in blood plasma to blood-oxygenation-level-dependent (BOLD) signal changes in hyperoxic calibrated BOLD studies. METHODS: Bovine blood plasma samples were prepared with partial pressures of oxygen (pO2 ) ranging from 110 to 600 mmHg. R1 , R2 , and R2* of the plasma with dissolved oxygen were measured using quantitative MRI sequences at 3 Tesla. Simulations were performed to predict the relative effects of dissolved oxygen and deoxyhemoglobin changes in hyperoxia calibrated BOLD. RESULTS: The relaxivities of dissolved oxygen in plasma were found to be r1,O2 =1.97 ± 0.09 ×10-4 s-1 mmHg-1 , r2,O2 =2.3 ± 0.7 ×10-4 s-1 mmHg-1 , and r2,O2* = 2.3 ± 0.7 ×10-4 s-1 mmHg-1 . Simulations predict that neither the transverse nor longitudinal relaxation rates of dissolved oxygen contribute significantly to the BOLD signal during hyperoxia. CONCLUSION: During hyperoxia, the increases in R2 and R2* of blood from dissolved oxygen in plasma are considerably less than the decreases in R2 and R2* from venous deoxyhemoglobin. R1 effects due to dissolved oxygen are also predicted to be negligible. As a result, dissolved oxygen in arteries should not contribute significantly to the hyperoxic calibrated BOLD signal. Magn Reson Med 76:1905-1911, 2016.
PURPOSE: To determine the contribution of paramagnetic dissolved oxygen in blood plasma to blood-oxygenation-level-dependent (BOLD) signal changes in hyperoxic calibrated BOLD studies. METHODS:Bovine blood plasma samples were prepared with partial pressures of oxygen (pO2 ) ranging from 110 to 600 mmHg. R1 , R2 , and R2* of the plasma with dissolved oxygen were measured using quantitative MRI sequences at 3 Tesla. Simulations were performed to predict the relative effects of dissolved oxygen and deoxyhemoglobin changes in hyperoxia calibrated BOLD. RESULTS: The relaxivities of dissolved oxygen in plasma were found to be r1,O2 =1.97 ± 0.09 ×10-4 s-1 mmHg-1 , r2,O2 =2.3 ± 0.7 ×10-4 s-1 mmHg-1 , and r2,O2* = 2.3 ± 0.7 ×10-4 s-1 mmHg-1 . Simulations predict that neither the transverse nor longitudinal relaxation rates of dissolved oxygen contribute significantly to the BOLD signal during hyperoxia. CONCLUSION: During hyperoxia, the increases in R2 and R2* of blood from dissolved oxygen in plasma are considerably less than the decreases in R2 and R2* from venous deoxyhemoglobin. R1 effects due to dissolved oxygen are also predicted to be negligible. As a result, dissolved oxygen in arteries should not contribute significantly to the hyperoxic calibrated BOLD signal. Magn Reson Med 76:1905-1911, 2016.
Authors: Allen A Champagne; Nicole S Coverdale; Mike Germuska; Alex A Bhogal; Douglas J Cook Journal: J Cereb Blood Flow Metab Date: 2019-07-15 Impact factor: 6.200
Authors: Sascha Brunheim; Sören Johst; Viktor Pfaffenrot; Stefan Maderwald; Harald H Quick; Benedikt A Poser Journal: MAGMA Date: 2017-07-10 Impact factor: 2.310
Authors: Allen A Champagne; Nicole S Coverdale; Juan Fernandez-Ruiz; Clarisse I Mark; Douglas J Cook Journal: Brain Imaging Behav Date: 2021-02 Impact factor: 3.978
Authors: Esra Abaci Turk; Jeffrey N Stout; Christopher Ha; Jie Luo; Borjan Gagoski; Filiz Yetisir; Polina Golland; Lawrence L Wald; Elfar Adalsteinsson; Julian N Robinson; Drucilla J Roberts; William H Barth; P Ellen Grant Journal: Top Magn Reson Imaging Date: 2019-10
Authors: Jeffrey N Stout; Congyu Liao; Borjan Gagoski; Esra Abaci Turk; Henry A Feldman; Carolina Bibbo; William H Barth; Scott A Shainker; Lawrence L Wald; P Ellen Grant; Elfar Adalsteinsson Journal: Placenta Date: 2021-08-24 Impact factor: 3.287
Authors: Vittorio Stumpo; Martina Sebök; Christiaan Hendrik Bas van Niftrik; Katharina Seystahl; Nicolin Hainc; Zsolt Kulcsar; Michael Weller; Luca Regli; Jorn Fierstra Journal: MAGMA Date: 2021-12-07 Impact factor: 2.310