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IJsselstijn H, Hunfeld M, Schiller RM, Houmes RJ, Hoskote A, Tibboel D, van Heijst AFJ. Improving Long-Term Outcomes After Extracorporeal Membrane Oxygenation: From Observational Follow-Up Programs Toward Risk Stratification. Front Pediatr 2018; 6:177. [PMID: 30013958 PMCID: PMC6036288 DOI: 10.3389/fped.2018.00177] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/30/2018] [Indexed: 01/02/2023] Open
Abstract
Since the introduction of extracorporeal membrane oxygenation (ECMO), more neonates and children with cardiorespiratory failure survive. Interest has therefore shifted from reduction of mortality toward evaluation of long-term outcomes and prevention of morbidity. This review addresses the changes in ECMO population and the ECMO-treatment that may affect long-term outcomes, the diagnostic modalities to evaluate neurological morbidities and their contributions to prognostication of long-term outcomes. Most follow-up data have only become available from observational follow-up programs in neonatal ECMO-survivors. The main topics are discussed in this review. Recommendations for long-term follow up depend on the presence of neurological comorbidity, the nature and extent of the underlying disease, and the indication for ECMO. Follow up should preferably be offered as standard of care, and in an interdisciplinary, structured and standardized way. This permits evaluation of outcome data and effect of interventions. We propose a standardized approach and recommend that multiple domains should be evaluated during long-term follow up of neonates and children who needed extracorporeal life support.
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Affiliation(s)
- Hanneke IJsselstijn
- Division of Pediatric Intensive Care, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands.,Department of Pediatric Surgery, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands
| | - Maayke Hunfeld
- Division of Pediatric Intensive Care, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands
| | - Raisa M Schiller
- Division of Pediatric Intensive Care, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands.,Department of Pediatric Surgery, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands
| | - Robert J Houmes
- Division of Pediatric Intensive Care, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands.,Department of Pediatric Surgery, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands
| | - Aparna Hoskote
- Department of Cardiac Intensive Care, Great Ormond Street Institute of Child Health, University College London and Great Ormond Street Hospital for Children, London, United Kingdom
| | - Dick Tibboel
- Division of Pediatric Intensive Care, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands.,Department of Pediatric Surgery, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, Netherlands
| | - Arno F J van Heijst
- Department of Neonatology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, Netherlands
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Chen YW, Hwang DW. Multi-chromatic magnetic resonance imaging using frequency lock-in suppression. NMR IN BIOMEDICINE 2015; 28:1187-1195. [PMID: 26282163 DOI: 10.1002/nbm.3361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 06/02/2015] [Accepted: 06/15/2015] [Indexed: 06/04/2023]
Abstract
This study developed a multi-chromatic MR contrast using the frequency lock-in technique. An electronic feedback device that generates a specific narrow-frequency-bandwidth RF field is presented. The effects of this RF field on MR images are assessed both theoretically and experimentally. Spectroscopy and imaging experiments were performed. Frequency tuning allowed the selected spectral peak to be suppressed. Phantom tests using methanol, ethanol, and water showed different contrasts using different feedback RF field frequencies. The frequency lock-in was also found to help differentiate among the small structural variations in biological tissues. The contrast achieved in in vivo mouse brain imaging using the lock-in suppressed technique indicated a better spatial discrimination when compared with that achieved using conventional imaging methods, especially in the hippocampus region. Selective lock-in suppressed imaging is a new approach to provide frequency information in MRI; rather than determining the evolution of image contrast over time, this approach allows small susceptibility variations to be distinguished by tuning the frequency of the narrow-bandwidth lock-in RF field. A new and enhanced contrast can be achieved using this technique.
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Affiliation(s)
- Yu-Wen Chen
- Department of Chemistry and Biochemistry, National Chung Cheng University, Min-Hsiung Township, Chiayi, Taiwan
| | - Dennis W Hwang
- Department of Chemistry and Biochemistry, National Chung Cheng University, Min-Hsiung Township, Chiayi, Taiwan
- Center for Nano Bio-detection, AIM-HI, National Chung Cheng University, Min-Hsiung Township, Chiayi, Taiwan
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3
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Qian C, Duan Q, Dodd S, Koretsky A, Murphy-Boesch J. Sensitivity Enhancement of an Inductively Coupled Local Detector Using a HEMT-Based Current Amplifier. Magn Reson Med 2015; 75:2573-8. [PMID: 26192998 DOI: 10.1002/mrm.25850] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/12/2015] [Accepted: 06/27/2015] [Indexed: 01/26/2023]
Abstract
PURPOSE To improve the signal transmission efficiency and sensitivity of a local detection coil that is weakly inductively coupled to a larger receive coil. METHODS The resonant detection coil is connected in parallel with the gate of a high electron mobility transistor (HEMT) transistor without impedance matching. When the drain of the transistor is capacitively shunted to ground, current amplification occurs in the resonator by feedback that transforms a capacitive impedance on the transistor's source to a negative resistance on its gate. RESULTS High resolution images were obtained from a mouse brain using a small, 11 mm diameter surface coil that was inductively coupled to a commercial, phased array chest coil. Although the power consumption of the amplifier was only 88 μW, 14 dB gain was obtained with excellent noise performance. CONCLUSION An integrated current amplifier based on a HEMT can enhance the sensitivity of inductively coupled local detectors when weakly coupled. This amplifier enables efficient signal transmission between customized user coils and commercial clinical coils, without the need for a specialized signal interface. Magn Reson Med 75:2573-2578, 2016. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Chunqi Qian
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA.,Department of Radiology, Michigan State University, East Lansing, Michigan, USA
| | - Qi Duan
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Steve Dodd
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Alan Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Joe Murphy-Boesch
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Li Z, Hsu CH, Dimitrov N, Hwang DW, Chang HW, Hwang LP, Lin YY. Sensitive imaging of magnetic nanoparticles for cancer detection by active feedback MR. Magn Reson Med 2015; 74:33-41. [PMID: 25845581 DOI: 10.1002/mrm.25632] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 12/31/2014] [Accepted: 01/03/2015] [Indexed: 12/23/2022]
Abstract
PURPOSE Sensitive imaging of superparamagnetic nanoparticles or aggregates is of great importance in MR molecular imaging and medical diagnosis. For this purpose, a conceptually new approach, termed active feedback magnetic resonance, was developed. METHODS In the presence of the Zeeman field, a dipolar field is induced by the superparamagnetic nanoparticles or aggregates. Such dipolar field creates spatial and temporal (due to water diffusion) variations to the precession frequency of the nearby water 1 H magnetization. Sensitive imaging of magnetic nanoparticles or aggregates can be achieved by manipulating the intrinsic spin dynamics by selective self-excitation and fixed-point dynamics under active feedback fields. RESULTS Phantom experiments of superparamagnetic nanoparticles; in vitro experiments of brain tissue with blood clots; and in vivo mouse images of colon cancers, with and without labeling by magnetic nanoparticles, suggest that this new approach provides enhanced, robust, and positive contrast in imaging magnetic nanoparticles or aggregates for cancer detection. CONCLUSION The spin dynamics originated from selective self-excitation and fixed-point dynamics under active feedback fields have been shown to be sensitive to dipolar fields generated by magnetic nanoparticles. Magn Reson Med 74:33-41, 2015. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Zhao Li
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
| | - Chao-Hsiung Hsu
- Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan.,Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
| | - Nikolay Dimitrov
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
| | - Dennis W Hwang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
| | - Hsin-Wei Chang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Lian-Pin Hwang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yung-Ya Lin
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, USA
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Chen YW, Hsu CH, Hsu CH, Hwang DW. Novel MRI contrast development by lock-in suppression. Magn Reson Med 2014; 71:1676-81. [PMID: 24604473 DOI: 10.1002/mrm.25162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/12/2014] [Accepted: 01/14/2014] [Indexed: 11/06/2022]
Abstract
PURPOSE The goal of this study is to develop novel MR contrast by frequency lock-in technique. METHODS An electronic feedback device that can control the frequency and bandwidth of the feedback RF field is presented. In this study, the effects of lock-in suppressed imaging are discussed both theoretically and experimentally. RESULTS Two important imaging experiments were performed. The first experiment used magnetizations with the same central frequency but different frequency distributions and was compared with MR images obtained with T2 contrast agents. Lock-in suppressed images showed an improvement in contrast relative to the conventional imaging method. The second experiment used magnetizations with small shifts in frequency and a broad frequency distribution. This is helpful for differentiating between small structural variations in biological tissues. The contrast achieved in in vivo tumor imaging using the lock-in suppressed technique provide higher spatial resolutions and discriminate the regimes of necrosis and activation consistent with pathologic results. CONCLUSION Lock-in suppressed imaging introduces a conceptually new approach to MRI. Heightened sensitivity to underlying susceptibility variations and their relative contribution to total magnetization may thus be achieved to yield new and enhanced contrast.
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Affiliation(s)
- Yu-Wen Chen
- Department of Chemistry and Biochemistry, National Chung Cheng University, Min-Hsiung Township Chiayi, Taiwan
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Phung J, Krogstad P, Mathern GW. Etiology associated with developing posthemispherectomy hydrocephalus after resection-disconnection procedures. J Neurosurg Pediatr 2013; 12:469-75. [PMID: 24011367 DOI: 10.3171/2013.8.peds13212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The authors sought to determine if clinical epilepsy variables, maximum daily temperature (Tmax), and blood and CSF findings were associated with the risk of developing hydrocephalus after first-time resection-disconnection hemispherectomy. METHODS Patients who underwent cerebral hemispherectomy in whom a standardized perioperative protocol was used, including the use of ventriculostomies (n = 79), were classified into those who developed and those who did not develop hydrocephalus requiring CSF shunts. The authors compared these 2 groups for clinical variables, Tmax, and blood and CSF studies through postoperative Day 12. RESULTS In this cohort, 30% of the patients required CSF shunts, of which 8% developed late hydrocephalus up to 3 years posthemispherectomy. Multivariate analysis found that etiology was associated with developing posthemispherectomy hydrocephalus. Higher shunt rates were observed for patients with hemimegalencephaly (40%; n = 15) and a history of CNS infection (100%; n = 4) compared with cortical dysplasia (17%; n = 23) and Rasmussen encephalitis (17%; n = 12). In univariate analysis, other factors associated with developing hydrocephalus were elevated maximum daily temperatures, elevated white blood cell counts, decreased CSF protein, and increased CSF red blood cell counts. CONCLUSIONS The findings of the study indicate that etiology was the factor most strongly associated with developing posthemispherectomy hydrocephalus. These findings suggest that there are variable mechanisms for developing hydrocephalus after cerebral hemispherectomy depending on the procedure, and in resection-disconnection operations the mechanism may involve changes in CSF bulk flow that varies by histopathology.
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Affiliation(s)
- Jennifer Phung
- Departments of Neurosurgery and Psychiatry & Biobehavioral Sciences
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Desvaux H. Non-linear liquid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 70:50-71. [PMID: 23540576 DOI: 10.1016/j.pnmrs.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/31/2012] [Indexed: 06/02/2023]
Affiliation(s)
- Hervé Desvaux
- CEA, IRAMIS, SIS2M, UMR CEA/CNRS 3299, Laboratoire Structure et Dynamique par Résonance Magnétique, CEA/Saclay, Gif-sur-Yvette, France.
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Cho JH, Cho JG, Chung KC, Yu HY, Ryu EK, Ahn SD, Lee CH. Experimental Analyses on Contrast Behaviors of iDQC and iTQC MR Images at 4.7 T. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.6.2113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Tabuchi Y, Negoro M, Takeda K, Kitagawa M. Total compensation of pulse transients inside a resonator. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 204:327-332. [PMID: 20378380 DOI: 10.1016/j.jmr.2010.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 03/09/2010] [Accepted: 03/18/2010] [Indexed: 05/29/2023]
Abstract
The profile of rf pulses that nuclear spins experience inside a resonator deviates from that of rf voltage signals generated by a NMR spectrometer according to users' pulse programming, when change of the profile in time is comparable to or shorter than the time constant of the resonator. In our previous work [Takeda et al., J. Magn. Reson. 197 (2009) 242-244], we proposed active compensation of rf pulse transients, in which the amplitude transient of the rf pulse can be suppressed without sacrificing the Q factor of the probe. Here we extend the idea of active compensation toward total compensation of the amplitude as well as phase transients. By measuring the transient response of the probe to a given excitation using a pickup coil, the response function determining the transient behavior of the probe is numerically obtained. Then, by numerically solving the convolution equation with the help of Laplace transformation, one can obtain the amplitude and phase profiles of the pulse that should be programmed in the spectrometer in order to apply the rf pulses to the nuclear spins as intended. Accurate rf pulsing based on this idea is experimentally demonstrated, and prospect and requirements for coping with the receiver dead-time problem are discussed.
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Affiliation(s)
- Y Tabuchi
- Division of Advanced Electronics and Optical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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Peng L, Cai S, Fu R, Ye C, Chen Z. Harmonic peaks in 1D NMR spectra induced by radiation damping fields. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Huang SY, Yang SS, Lin YY. Sensitivity of feedback-enhanced MRI contrast to macroscopic and microscopic field variations. Magn Reson Med 2009; 61:925-36. [DOI: 10.1002/mrm.21584] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Huang SY, Witzel T, Wald LL. Accelerated radiation damping for increased spin equilibrium (ARISE): a new method for controlling the recovery of longitudinal magnetization. Magn Reson Med 2009; 60:1112-21. [PMID: 18956463 DOI: 10.1002/mrm.21702] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Control of the longitudinal magnetization in fast gradient-echo (GRE) sequences is an important factor in enabling the high efficiency of balanced steady-state free precession (bSSFP) sequences. We introduce a new method for accelerating the return of the longitudinal magnetization to the +z-axis that is independent of externally applied RF pulses and shows improved off-resonance performance. The accelerated radiation damping for increased spin equilibrium (ARISE) method uses an external feedback circuit to strengthen the radiation damping (RD) field. The enhanced RD field rotates the magnetization back to the +z-axis at a rate faster than T(1) relaxation. The method is characterized in GRE phantom imaging at 3T as a function of feedback gain, phase, and duration, and compared with results from numerical simulations of the Bloch equations incorporating RD. A short period of feedback (10 ms) during a refocused interval of a crushed GRE sequence allowed greater than 99% recovery of the longitudinal magnetization when very little T(2) relaxation had time to occur. An appropriate application might be to improve navigated sequences. Unlike conventional flip-back schemes, the ARISE "flip-back" is generated by the spins themselves, thereby offering a potentially useful building block for enhancing GRE sequences.
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Affiliation(s)
- Susie Y Huang
- Department of Radiology, Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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Effects on 1H and 129Xe NMR spectra of large magnetization created by dissolved laser-polarized xenon. CR CHIM 2008. [DOI: 10.1016/j.crci.2007.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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van de Ven RCG, Hogers B, van den Maagdenberg AMJM, de Groot HJM, Ferrari MD, Frants RR, Poelmann RE, van der Weerd L, Kiihne SR. T1 relaxation in in vivo mouse brain at ultra-high field. Magn Reson Med 2007; 58:390-5. [PMID: 17654587 DOI: 10.1002/mrm.21313] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Accurate knowledge of relaxation times is imperative for adjustment of MRI parameters to obtain optimal signal-to-noise ratio (SNR) and contrast. As small animal MRI studies are extended to increasingly higher magnetic fields, these parameters must be assessed anew. The goal of this study was to obtain accurate spin-lattice (T(1)) relaxation times for the normal mouse brain at field strengths of 9.4 and 17.6 T. T(1) relaxation times were determined for cortex, corpus callosum, caudate putamen, hippocampus, periaqueductal gray, lateral ventricle, and cerebellum and varied from 1651 +/- 28 to 2449 +/- 150 ms at 9.4 T and 1824 +/- 101 to 2772 +/- 235 ms at 17.6 T. A field strength-dependent increase of T(1) relaxation times is shown. The SNR increase at 17.6 T is in good agreement with the expected SNR increase for a sample-dominated noise regime.
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Affiliation(s)
- Rob C G van de Ven
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Huang SY, Furuyama JK, Lin YY. Designing feedback-based contrast enhancement for in vivo imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2006; 19:333-46. [PMID: 17171385 DOI: 10.1007/s10334-006-0061-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 11/07/2006] [Accepted: 11/15/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Nonlinear feedback interactions induced by the spins themselves have recently been introduced as novel MRI contrast enhancement mechanisms sensitive to small differences in MR parameters. Developing feedback-based contrast enhancement into a useful tool for in vivo imaging requires improved techniques that are robust to inhomogeneity and sensitive to subtle anatomical/physiological variations. MATERIALS AND METHODS Three different imaging methods combining the radiation damping feedback field with the distant dipolar field, applied radio-frequency (RF) fields, and local dipole fields, respectively, were designed and tested through numerical simulations on simple phantoms. These methods were demonstrated experimentally on live guppy fish, developing frog embryos, and blood in in vitro tissue samples by microimaging at 14.1 T. RESULTS The developed feedback-based methods yielded images that identified distinct morphological features with superior contrast compared with conventional MR images and those acquired under radiation damping only. Positive contrast due to evolution under radiation damping and local dipole fields was also observed in SPIOs and blood. CONCLUSION Approaches to enhancing feedback-based contrast were successfully designed and demonstrated in vitro and in vivo. The newly devised methods were less sensitive to field inhomogeneity and prolonged evolution under the feedback fields, allowing for better visualization of contrast in vivo.
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Affiliation(s)
- Susie Y Huang
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095-1569, USA
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