Abstract
The purpose of this prospective study was to determine the oxygen saturation of blood in the fetal brain based on T2 and T2* measurements in a fetal sheep model. Five sheep fetuses were investigated during normoxia and hypoxia by 3T MRI. Multi-echo gradient-echo and turbo-spin-echo sequences were performed on the fetal brain. MR-determined oxygen saturation (MR-sO2) of blood in the fetal brain was calculated based on T2 and T2* values. Fetal arterial blood oxygen saturation (blood-sO2) was measured during the two experimental phases. The slope of MR-sO2 as a function of blood-sO2 was estimated and tested for compatibility using the one-sample t-test. During normoxia, mean values for carotid blood oxygen saturation were 67%, 83 ms for T2*, 202 ms for T2 and 96% for MR-sO2. During hypoxia, arterial blood oxygen saturation, T2* and calculated MR-sO2 decreased to 22%, 64 ms, and 68% respectively. The one-sample t-test revealed the slope to be significantly different from 0 (T = 5.023, df = 4, P = 0.007). It is feasible to perform quantitative T2 and T2* measurements in the fetal brain. MR-sO2 and fetal arterial blood oxygen saturation correlated significantly. However, based on these data a reliable quantification of fetal brain tissue oxygenation is not possible.
References
Tuunanen PI, Kauppinen RA (2006) Effects of oxygen saturation on BOLD and arterial spin labelling perfusion fMRI signals studied in a motor activation task. Neuroimage 30:102–109
Ogawa S, Lee TM, Kay AR, Tank DW (1990) Brain magnetic resonance imaging with contrast dependent on blood oxygenation. Proc Natl Acad Sci 87:9868–9872
Wedegärtner U, Tchirikov M, Koch M, Adam G, Schröder H (2002) Functional magnetic resonance imaging (fMRI) for fetal oxygenation during maternal hypoxia: initial results. Fortschr Röntgenstr 174:700–703
Wedegärtner U, Tchirikov M, Schäfer S, Priest A, Walther M, Adam G, Schröder H (2005) Functional MRI (BOLD) at 3 Tesla in the brain of fetal sheep: methodological aspects and the relation to maternal blood oxygenation during hypoxia. Radiology 237:919–926
Ogawa S, Lee TM, Barrere B (1993) The sensitivity of magnetic resonance image signals of a rat brain to changes in the cerebral venous blood oxygenation. Magn Reson Med 29:205–210
Yablonskiy DA, Haacke EM (1994) Theory of NMR signal behavior in magnetically inhomogenous tissues: the static dephasing regime. MRM 32:749–763
van Cappellen AM, Heerschap A, Nijhuis JG, Oeseburg B, Jongsma HW (1999) Hypoxia, the subsequent systemic metabolic acidosis, and their relationship with cerebral metabolite concentrations: an in vivo study in fetal lambs with proton magnetic resonance spectroscopy. Am J Obstet Gynecol 181:1537–1545
He X, Yablonskiy DA (2007) Quantitative BOLD: mapping of human cerebral deoxygenated blood volume and oxygen extraction fraction: default state. Magn Reson Med 57:115–126
He X, Zhu M, Yablonskiy DA (2008) Validation of oxygen extraction fraction measurement by qBOLD technique. Magn Reson Med 60:882–888
Dahnke H, Schaeffter T (2005) Limits of detection of SPIO at 3.0 T using T2 relaxometry. Magn Reson Med 53:1202–1206
Julien-Dolbec C, Tropres I, Montigon O, Reutenauer H, Ziegler A, Decorps M, Payen JF (2002) Regional response of cerebral blood volume to graded hypoxic hypoxia in rat brain. Br J Anaesth 89:287–293
Kennan RP, Scanley BE, Gore J (1997) Physiological basis of BOLD MR signal changes due to hypoxia/hyperoxia: separation of blood volume and magnetic susceptibility effects. Magn Reson Med 37:353–356
Lin W, Celik A, Paczynski RP, Hsu C, Powers W (1999) Quantitative magnetic resonance imaging in experimental hypercapnia: improvement in the relation between changes in brain R2* and the oxygen saturation of venous blood after correction of changes in cerebral blood volume. J Cereb Blood Flow Metab 19:853–862
Posse S, Kemna LJ, Elghahwagi B, Wiese S, Kiselev VG (2001) Effect of graded hypo- and hypercapnia on fMRI contrast in visual cortex: quantification of T2* changes by multiecho EPI. Magn Reson Med 46:264–271
Spees WM, Yablonskiy DA, Oswood MC, Ackerman JJ (2001) Water proton MR properties of human blood at 1.5 Tesla: magnetic susceptibility, T(1), T(2), T*(2), and non-Lorentzian signal behavior. Magn Reson Med 45:533–542
Leenders KL, Perani D, Lammertsma AA, Heather JD, Buckingham P, Healy MJ, Gibbs JM, Wise RJ, Hatazawa J, Herold S et al (1990) Cerebral blood flow, blood volume and oxygen utilization. Normal values and effect of age. Brain 113:27–47
Ito H, Kanno I, Iida H, Hatazawa J, Shimosegawa E, Tamura H, Okudera T (2001) Arterial fraction of cerebral blood volume in humans measured by positron emission tomography. Ann Nucl Med 15:111–116
Jones MD, Sheldon RE, Peeters LL, Meschia G, Battaglia FC, Makowski EL (1977) Fetal cerebral oxygen consumption at different levels of oxygenation. J Appl Physiol 43:1080–1084
Gelman N, Gorell JM, Barker PB, Savage RM, Spickler EM, Windham JP, Knight RA (1999) MR imaging of human brain at 3.0 T: preliminary report on transverse relaxation rates and relation to estimated iron content. Radiology 210:759–767
Ogawa S, Menon RS, Tank DW, Kim SG, Markle H, Ellermann JM, Ugurbil K (1993) Functional brain mapping by blood oxygenation level dependent contrast magnetic resonance imaging. Biophys J 64:803–812
Prielmeier F, Nagatomo Y, Frahm J (1994) Cerebral blood oxygenation in rat brain during hypoxic hypoxia: quantitative MRI of effective transverse elaxation rates. Magn Reson Med 31:678–681
Thulborn KR, Waterton JC, Matthews PM, Radda GK (1982) Oxygenation dependence of the transverse relaxation time of water protons in whole blood at high field. Biochim Biophys Acta 714:265–270
Punwani S, Ordidge RJ, Cooper CE, Amess P, Clemence M (1998) MRI measurements of cerebral deoxyhemoglobin concentration [dHb] - correlation with near infrared spectroscopy (NIRS). NMR Biomed 11:281–289
Hoppel BE, Weisskoff RM, Thulborn KR, Moore JB, Kwong KK, Rosen BR (1993) Measurement of regional blood oxygenation and cerebral hemodynamics. Magn Reson Med 30:715–723
Turner R, Le Bihan D, Moonen CTW, Despres D, Frank J (1991) Echo-planar time course MRI of cat brain oxygenation changes. Magn Reson Med 22:159–166
Kwong KK, Wanke I, Donahue KM, Davis TL (1995) EPI imaging of global increase of brain MR signal with breath-hold preceded by breathing O2. Magn Reson Med 33:448–452
Kontos HA, Wei EP, Raper AJ, Rosenblum WI, Navari RM, Patterson JL (1978) Role of tissue hypoxia in local regulation of cerebral microcirculation. Am J Physiol 234:H582–H591
Jezzard P, Heineman F, Taylor J, DesPres D, Wen H, Balaban RS, Turner R (1994) Comparison of EPI gradient-echo contrast changes in cat brain caused by respiratory challenges with direct simultaneous evaluation of cerebral oxygenation via a cranial window. NMR Biomed 7:35–44
Rostrup E, Larsson HBW, Toft PB, Garde K, Henriksen O (1995) Signal changes in gradient-echo images of human brain induced by hypo- and hyperoxia. NMR Biomed 8:41–47
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This work was supported by the Deutsche Forschungsgemeinschaft We 2826/1-2.
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Wedegärtner, U., Kooijman, H., Andreas, T. et al. T2 and T2* measurements of fetal brain oxygenation during hypoxia with MRI at 3T: correlation with fetal arterial blood oxygen saturation. Eur Radiol 20, 121–127 (2010). https://doi.org/10.1007/s00330-009-1513-4
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DOI: https://doi.org/10.1007/s00330-009-1513-4