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Handa P, Samkaria A, Sharma S, Arora Y, Mandal PK. Comprehensive Account of Sodium Imaging and Spectroscopy for Brain Research. ACS Chem Neurosci 2022; 13:859-875. [PMID: 35324144 DOI: 10.1021/acschemneuro.2c00027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Sodium (23Na) is a vital component of neuronal cells and plays a key role in various signal transmission processes. Hence, information on sodium distribution in the brain using magnetic resonance imaging (MRI) provides useful information on neuronal health. 23Na MRI and MR spectroscopy (MRS) improve the diagnosis, prognosis, and clinical monitoring of neurological diseases but confront some inherent limitations that lead to low signal-to-noise ratio, longer scan time, and diminished partial volume effects. Recent advancements in multinuclear MR technology have helped in further exploration in this domain. We aim to provide a comprehensive description of 23Na MRI and MRS for brain research including the following aspects: (a) theoretical background for understanding 23Na MRI and MRS fundamentals; (b) technological advancements of 23Na MRI with respect to pulse sequences, RF coils, and sodium compartmentalization; (c) applications of 23Na MRI in the early diagnosis and prognosis of various neurological disorders; (d) structural-chronological evolution of sodium spectroscopy in terms of its numerous applications in human studies; (e) the data-processing tools utilized in the quantitation of sodium in the respective anatomical regions.
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Affiliation(s)
- Palak Handa
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122051, India
| | - Avantika Samkaria
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122051, India
| | - Shallu Sharma
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122051, India
| | - Yashika Arora
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122051, India
| | - Pravat K. Mandal
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122051, India
- Florey Institute of Neuroscience and Mental Health, Melbourne School of Medicine Campus, Melbourne 3010, Australia
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Burstein D, Springer CS. Sodium MRI revisited. Magn Reson Med 2019; 82:521-524. [PMID: 30927278 DOI: 10.1002/mrm.27738] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/01/2019] [Accepted: 02/24/2019] [Indexed: 02/04/2023]
Affiliation(s)
- Deborah Burstein
- Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Charles S Springer
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon
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Schepkin VD, Lee KC, Kuszpit K, Muthuswami M, Johnson TD, Chenevert TL, Rehemtulla A, Ross BD. Proton and sodium MRI assessment of emerging tumor chemotherapeutic resistance. NMR IN BIOMEDICINE 2006; 19:1035-42. [PMID: 16894643 PMCID: PMC3140794 DOI: 10.1002/nbm.1074] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The ultimate goal of any cancer therapy is to target the elimination of neoplastic cells. Although newer therapeutic strategies are in constant development, therapeutic assessment has been hampered by the inability to assess, rapidly and quantitatively, efficacy in vivo. Diffusion imaging and, more recently, sodium MRI have demonstrated their distinct abilities to detect therapy-induced alterations in tumor cellularity, which has been demonstrated to be indicative of therapeutic efficacy. More importantly, both imaging modalities detect tumor response much earlier than traditional methodologies that rely on macroscopic volumetric changes. In this study, the correlation between tumor sodium and diffusion was further tested to demonstrate the sensitivity of sodium imaging to gauge tumor response to therapy by using a 9L rat gliosarcoma treated with varying doses of BCNU [1,3-bis(2-chloroethyl)-1-nitrosourea]. This orthotopic model has been demonstrated to display variability in response to BCNU therapy where initial insult has been shown to lead to drug-resistance. In brief, a single 26.6 mg/kg BCNU dose yielded dramatic responses in both diffusion and sodium MRI. However, a second equivalent BCNU dose yielded a much smaller change in diffusion and sodium, suggesting a drop in tumor sensitivity to BCNU. The MRI responses of animals treated with 13.3 mg/kg BCNU were much lower and similar responses were observed after the initial and secondary applications of BCNU. Furthermore, these results were further validated using volumetric measurements of the tumor and also ex vivo determination of tumor sensitivity to BCNU. Overall, these experiments demonstrate the sensitivity and applicability of sodium and diffusion MRI as tools for dynamic assessment of tumor response to therapy.
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Affiliation(s)
- Victor D. Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Kuei C. Lee
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Kyle Kuszpit
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Mukilan Muthuswami
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Timothy D. Johnson
- Department of Biostatistics, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Thomas L. Chenevert
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Alnawaz Rehemtulla
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
| | - Brian D. Ross
- Department of Radiology, Center for Molecular Imaging, University of Michigan Medical School, Ann Arbor, MI 48109-0503, USA
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Ouwerkerk R, Weiss RG, Bottomley PA. Measuring human cardiac tissue sodium concentrations using surface coils, adiabatic excitation, and twisted projection imaging with minimal T2 losses. J Magn Reson Imaging 2005; 21:546-55. [PMID: 15834912 DOI: 10.1002/jmri.20322] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To measure tissue sodium concentrations in the human heart with (23)Na MRI using a surface coil, thereby eliminating the effects of inhomogeneous excitation by surface coils and minimizing T(1) and T(2) relaxation. MATERIALS AND METHODS We combined fully relaxed, very short-echo, (23)Na twisted projection imaging (TPI) with adiabatic half passage (AHP) excitation and external referencing on subjects and comparing with a concentration reference phantom scan to quantify TSC with surface coils. (23)Na signal losses during hard (square), composite, and tanh/tan amplitude/frequency-modulated AHP excitation pulses were analyzed over a wide range of RF field strengths and T(2short) values. RESULTS AHP excitation yielded a homogeneous excitation flip angle and negligible losses compared to a 90 degrees hard pulse wherever the B1 field exceeded the adiabatic threshold, rendering this sequence suitable for applications that use surface coil excitation. An AHP (23)Na TPI sequence was used with a surface coil at 1.5 T to noninvasively quantify myocardial TSC in 10 normal volunteers. The mean TSC was 43 +/- 4, 53 +/- 12, and 17 +/- 4 micromol/g in the left ventricular (LV) free wall, septum, and adipose tissue, respectively, consistent with prior invasive measurements on biopsy and autopsy specimens. CONCLUSION It is now possible to noninvasively quantify TSC in the human heart with surface coil (23)Na MRI.
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Affiliation(s)
- Ronald Ouwerkerk
- Division of MR Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-0845, USA.
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Clayton DB, Lenkinski RE. MR imaging of sodium in the human brain with a fast three-dimensional gradient-recalled-echo sequence at 4 T. Acad Radiol 2003; 10:358-65. [PMID: 12678174 DOI: 10.1016/s1076-6332(03)80023-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
RATIONALE AND OBJECTIVES Sodium ions play a vital role in cellular homeostasis and electrochemical activity throughout the human body. However, the in vivo detection of sodium (23Na) with magnetic resonance (MR) techniques is hindered by the fast transverse relaxation, low tissue equivalent concentration, and small gyromagnetic ratio of sodium ions compared with protons (1H). The goals of this study were to acquire MR images of sodium in the whole human brain by using a fast three-dimensional gradient-recalled-echo sequence and to investigate the effect that restrictions on specific absorption ratio have on MR imaging of sodium at 4 T. MATERIALS AND METHODS A three-dimensional gradient-recalled-echo sequence with short echo time was developed for MR imaging of sodium. Slab encoding was removed and a hard excitation pulse was used. Five healthy human volunteers were examined in a whole-body MR imager with the use of a custom transmit-and-receive birdcage coil. Fields of view were selected to cover the entire brain: 38 x 38 cm in the axial plane, with 24 sections of 5.8 mm each or 12 sections of 1.1 cm each. The in-plane acquisition matrix was 64 x 128, and voxel size was 0.2 cm(3). RESULTS Sodium in white matter was depicted with an acceptable signal-to-noise ratio of 20-25. The echo time, and hence the signal-to-noise ratio, was limited by the MR imager's maximum allowable gradient strength. To keep the specific absorption ratio below 3 W/kg (the limit established by the Food and Drug Administration), it was necessary to prolong the repetition time to 30 msec. CONCLUSION The MR imaging protocol used in this study provided acceptable visualization of sodium in the whole brain in a tolerable total acquisition time of 15 minutes.
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Affiliation(s)
- David B Clayton
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
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Weidensteiner C, Horn M, Fekete E, Neubauer S, von Kienlin M. Imaging of intracellular sodium with shift reagent aided (23)Na CSI in isolated rat hearts. Magn Reson Med 2002; 48:89-96. [PMID: 12111935 DOI: 10.1002/mrm.10205] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
23Na chemical shift imaging (CSI) in conjunction with shift reagents was used to obtain images of intracellular (Na(i)) and extracellular sodium (Na(e)) in isolated rat hearts. It was demonstrated that the increase of Na(i) concentration in ischemic myocardium can be detected with this technique. 3D acquisition-weighted (23)Na CSI datasets with a nominal spatial resolution of 1.7 x 1.7 x 2.9 mm were acquired in 30 min in normoxic hearts and in globally or locally ischemic hearts. The shift reagent Tm(DOTP)(5-) was used to discriminate Na(i) and Na(e) signals. Na(i) maps could be generated in ischemic hearts, but not in normoxic hearts as the signal-to-noise ratio is too low. The Na(i) signal increased by more than 100% and the Na(e) signal decreased by more than 50% in myocardium of globally ischemic hearts (n = 3) compared to normoxic hearts (n = 3). In hearts with an acute occlusion of the left anterior descending coronary artery (n = 3), there was a local Na(i) signal increase in the anterior wall in the range of 60-110% compared to remote, normoxic tissue.
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Parrish TB, Fieno DS, Fitzgerald SW, Judd RM. Theoretical basis for sodium and potassium MRI of the human heart at 1.5 T. Magn Reson Med 1997; 38:653-61. [PMID: 9324333 DOI: 10.1002/mrm.1910380420] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Knowledge of the extent and location of viable tissue is important to clinical diagnosis. In principle, sodium (23Na) and potassium (39K) MRI could noninvasively provide information about tissue viability. In practice, imaging of these nuclei is difficult because, compared with water protons (1H), 23Na and 39K have lower MR sensitivities (9.2 and 0.051%, respectively), and lower in vivo concentrations (ca. 1000-fold). On the other hand, the relatively short T1 relaxation times of 23Na and 39K (ca. 30 and 10 ms, respectively) suggest that optimized imaging pulse sequences may in part alleviate the weak signal of these nuclei. In this study, numerical simulations of high-speed imaging sequences were developed and used to maximize 23Na and 39K image signal-to-noise ratio (SNR) per unit time within the constraints of existing gradient hardware. The simulation demonstrated that decreasing receiver bandwidth at the expense of echo time (TE) results in a substantial increase in 23Na and 39K image SNR/time despite the short T2 and T2* of these nuclei. Referenced to the available 1H signal on existing 1.5 T scanners, the simulation suggested that it should be possible to acquire three-dimensional 23Na images of the human heart with 7 x 7 x 7 mm resolution and 39K images with 26 x 26 x 26 mm resolution in 30 min. Experimentally in humans at 1.5 T, three-dimensional 23Na images of the heart were acquired in 15 min with 6 x 6 x 12 mm resolution and signal-to-noise ratios of 11 and 7 in the left ventricular cavity and myocardium, respectively, which is very similar to the predicted result. The results demonstrate that by choosing imaging pulse sequence parameters that fully exploit the short relaxation times of 23Na and 39K, potassium MRI is improved but remains impractical, whereas sodium MRI improves to the point where 23Na imaging of the human heart may be clinically feasible on existing 1.5 T scanners.
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Affiliation(s)
- T B Parrish
- Northwestern University Medical School, Feinberg Cardiovascular Research Institute, Department of Radiology, Chicago, Illinois 60611-3008, USA
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Kim RJ, Lima JA, Chen EL, Reeder SB, Klocke FJ, Zerhouni EA, Judd RM. Fast 23Na magnetic resonance imaging of acute reperfused myocardial infarction. Potential to assess myocardial viability. Circulation 1997; 95:1877-85. [PMID: 9107176 DOI: 10.1161/01.cir.95.7.1877] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The ability of the myocyte to maintain an ionic concentration gradient is perhaps the best indication of myocardial viability. We studied the relationship of 23Na MRI intensity to viability and explored the potential of fast-imaging techniques to reduce 23Na imaging times in rabbits and dogs. METHODS AND RESULTS Eighteen rabbits underwent in situ coronary artery occlusion and reperfusion. The hearts were then either imaged following isolation and perfusion with cardioplegic solution (n = 6), imaged in vivo (n = 6), or analyzed for 23Na content and relaxation times (n = 12). Normal rabbits (n = 6) and dogs (n = 4) were imaged to examine the effect of animal size on 23Na image quality. 23Na imaging times were 7, 11, and 4 minutes for isolated rabbits, in vivo rabbits, and in vivo dogs, respectively. Infarcted, reperfused regions, identified by triphenyltetrazolium chloride staining, showed a significant elevation in 23Na image intensity compared with viable regions (isolated, 42 +/- 5%, P < .02; in vivo, 95 +/- 6%, P < .001), consistent with increased tissue sodium content. Similarly, 23Na MR spectroscopy showed that [Na+] was higher in nonviable than viable myocardium (isolated, 99 +/- 4 versus 61 +/- 2 mmol/L; in vivo, 91 +/- 2 versus 38 +/- 1 mmol/L; P < .001 for both). Image signal-to-noise ratios were higher in dogs than rabbits despite shorter imaging times, primarily due to larger voxels. CONCLUSIONS Following acute infarction with reperfusion, a regional increase in 23Na MR image intensity is associated with nonviable myocardium. Fast gradient-echo imaging techniques reduce 23Na imaging times to a few minutes, suggesting that 23Na MR imaging has the potential to become a useful experimental and clinical tool.
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Affiliation(s)
- R J Kim
- Johns Hopkins Medical Institutions (R.J.K., J.A.C.L., S.B.R., E.A.Z.), Baltimore, Md, USA
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Schepkin VD, Choy IO, Budinger TF. Sodium alterations in isolated rat heart during cardioplegic arrest. J Appl Physiol (1985) 1996; 81:2696-702. [PMID: 9018524 DOI: 10.1152/jappl.1996.81.6.2696] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Triple-quantum-filtered (TQF) Na nuclear magnetic resonance (NMR) without chemical shift reagent is used to investigate Na derangement in isolated crystalloid perfused rat hearts during St. Thomas cardioplegic (CP) arrest. The extracellular Na contribution to the NMR TQF signal of a rat heart is found to be 73 +/- 5%, as determined by wash-out experiments at different moments of ischemia and reperfusion. With the use of this contribution factor, the estimated intracellular Na ([Na+]i) TQF signal is 222 +/- 13% of preischemic level after 40 min of CP arrest and 30 min of reperfusion, and the heart rate pressure product recovery is 71 +/- 8%. These parameters are significantly better than for stop-flow ischemia: 340 +/- 20% and 6 +/- 3%, respectively. At 37 degrees C, the initial delay of 15 min in [Na+]i growth occurs during CP arrest along with reduced growth later (approximately 4.0%/min) in comparison with stop-flow ischemia (approximately 6.7%/min). The hypothermia (21 degrees C, 40 min) for the stop-flow ischemia and CP dramatically decreases the [Na+]i gain with the highest heart recovery for CP (approximately 100%). These studies confirm the enhanced sensitivity of TQF NMR to [Na+]i and demonstrate the potential of NMR without chemical shift reagent to monitor [Na+]i derangements.
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Affiliation(s)
- V D Schepkin
- Center for Functional Imaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Dai H, McFarland EW. Characterization of polyion counterion interactions in cartilage by 23Na NMR relaxation. J Biomol Struct Dyn 1996; 13:873-83. [PMID: 8723780 DOI: 10.1080/07391102.1996.10508898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nuclear quadrupole relaxation is a sensitive measure of electrolyte environments. We used the relaxation of 23Na to probe mobile ion-matrix interactions and the electrostatic structure of the polyelectrolyte extracellular matrix of cartilage. Specifically, we measured spin-lattice and spin-spin relaxation times of 23Na in bovine nasal cartilage at 132 MHz under several conditions. Matrix fixed charge density was reduced by protonating anionic sites and by matrix digestion with trypsin and the relaxation times compared to controls. Under all conditions studied, measured longitudinal relaxation was monoexponential with values ranging from 16-32 msec. Transverse relaxation exhibited biexponential behavior in all cartilage samples with a fast component in the range of 2 to 5 ms and a slow component between 16 and 53 ms. Reduction in matrix fixed charge density in all cases led to a decrease in the relaxation rates. The results suggest a two-site model for Na+ ions in cartilage and a relaxation mechanism involving both polyion segmental motion and counterion diffusion. In the context of ion condensation theory, the implication of a two-site model is that the mean polyion-polyion spacing may be less than 0.7 nm. The mean polyion-counterion spacings were estimated by calculating correlation times and quadrupole coupling constants. These spacings were found to be 0.5-0.7 nm.
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Affiliation(s)
- H Dai
- Department of Chemical Engineering, University of California, Santa Barbara 93106, USA
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Dizon JM, Tauskela JS, Wise D, Burkhoff D, Cannon PJ, Katz J. Evaluation of triple-quantum-filtered 23Na NMR in monitoring of Intracellular Na content in the perfused rat heart: comparison of intra- and extracellular transverse relaxation and spectral amplitudes. Magn Reson Med 1996; 35:336-45. [PMID: 8699945 DOI: 10.1002/mrm.1910350311] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Multiple-quantum filtered (MQF) NMR offers the possibility of monitoring intracellular (IC) Na content in the absence of shift reagents (SR), provided that (i) the contribution from IC Na to the MQF spectrum is substantial and responds to a change in IC Na content, and (ii) the amplitude of the extracellular (EC) MQF component remains constant during a change in IC Na content. The validity and basis for these conditions were examined in isolated perfused rat hearts using SR-aided and SR-free triple-quantum filtered (TQF) 23NaNMR. Despite a myocardial Na content that was only approximately 1/70 that of EC Na. IC Na contributed to over 25% of the total TQF spectrum acquired in the absence of SR. Transverse relaxation times (T2) were approximately twice as long for EC compared to IC Na, despite SR-induced relaxation of T2 for the former pool. However, the efficiency of generation of the TQF signal was similar for IC and EC Na, indicating that a much greater percentage of IC relative to EC Na exhibits TQ coherence. During constant perfusion with ouabain (0.2 mM for 25 min) or with a hypoxic and aglycemic solution (50 min), the amplitude of the IC TQF spectrum increased by approximately 330% and -280%, respectively. In contrast, the amplitude of the EC TQF spectra remained essentially constant for both interventions. The amplitude for IC Na increased approximately 250% relative to baseline during no-flow ischemia (60 min), whereas the amplitude of the EC TQF spectra decreased by approximately 33% before stabilizing. In SR-free experiments, the TQF spectral amplitude increased approximately 2-fold during the constant perfusion interventions, but did not change significantly during no-flow ischemia. These data suggest that the change in the TQF spectral amplitude during constant perfusion interventions is from IC Na, and that TQF techniques in the absence of SR may be useful in monitoring IC Na during these interventions. The fall in the amplitude of the EC TQF spectral amplitude during no-flow ischemia complicates the use of TQF techniques without SR during this intervention.
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Affiliation(s)
- J M Dizon
- Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, New York 10032, USA
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