scholarly journals Magnetic Resonance-Compatible Arm-Crank Ergometry: A New Platform Linking Whole-Body Calorimetry to Upper-Extremity Biomechanics and Arm Muscle Metabolism

2021 ◽  
Vol 12 ◽  
Author(s):  
Riemer J. K. Vegter ◽  
Sebastiaan van den Brink ◽  
Leonora J. Mouton ◽  
Anita Sibeijn-Kuiper ◽  
Lucas H. V. van der Woude ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Surface Electromyography ◽  
Healthy Subjects ◽  
Muscle Disease ◽  
Upper Body ◽  
Whole Body ◽  
Muscle Coordination ◽  
Muscle Energetics ◽  
Arm Muscles

IntroductionEvaluation of the effect of human upper-body training regimens may benefit from knowledge of local energy expenditure in arm muscles. To that end, we developed a novel arm-crank ergometry platform for use in a clinical magnetic resonance (MR) scanner with 31P spectroscopy capability to study arm muscle energetics. Complementary datasets on heart-rate, whole-body oxygen consumption, proximal arm-muscle electrical activity and power output, were obtained in a mock-up scanner. The utility of the platform was tested by a preliminary study over 4 weeks of skill practice on the efficiency of execution of a dynamic arm-cranking task in healthy subjects.ResultsThe new platform successfully recorded the first ever in vivo31P MR spectra from the human biceps brachii (BB) muscle during dynamic exercise in five healthy subjects. Changes in BB energy- and pH balance varied considerably between individuals. Surface electromyography and mechanical force recordings revealed that individuals employed different arm muscle recruitment strategies, using either predominantly elbow flexor muscles (pull strategy; two subjects), elbow extensor muscles (push strategy; one subject) or a combination of both (two subjects). The magnitude of observed changes in BB energy- and pH balance during ACT execution correlated closely with each strategy. Skill practice improved muscle coordination but did not alter individual strategies. Mechanical efficiency on group level seemed to increase as a result of practice, but the outcomes generated by the new platform showed the additional caution necessary for the interpretation that total energy cost was actually reduced at the same workload.ConclusionThe presented platform integrates dynamic in vivo31P MRS recordings from proximal arm muscles with whole-body calorimetry, surface electromyography and biomechanical measurements. This new methodology enables evaluation of cyclic motor performance and outcomes of upper-body training regimens in healthy novices. It may be equally useful for investigations of exercise physiology in lower-limb impaired athletes and wheelchair users as well as frail patients including patients with debilitating muscle disease and the elderly.

scholarly journals Magnetic Resonance-Compatible Arm-Crank Ergometry: A New Platform Linking Whole-Body Calorimetry to Upper-Extremity Biomechanics and Arm Muscle Metabolism

2020 ◽  
Author(s):  
Riemer JK Vegter ◽  
Sebastiaan van den Brink ◽  
Leonora J Mouton ◽  
Anita Sibeijn-Kuiper ◽  
Lucas H.V. van der Woude ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Surface Electromyography ◽  
Motor Units ◽  
Daily Practice ◽  
Muscle Disease ◽  
Upper Body ◽  
Whole Body ◽  
Energetic Efficiency ◽  
The Impact

Abstract Background: Evaluation of the effect of human upper body training regimens may benefit from knowledge of local energy expenditure in arm muscles. To that end, we developed a novel asynchronous arm-crank ergometry platform for use in a clinical magnetic resonance (MR) scanner with 31P spectroscopy capability to study arm muscle energetics. The utility of the platform was tested in an investigation of the impact of daily practice on the energetic efficiency of execution of an arm-cranking task (ACT) in healthy subjects. Results: We recorded the first ever in vivo 31P MR spectra from the human biceps bracii muscle during ACT execution pre- and post-three weeks of daily practice bouts, respectively. Complementary datasets on whole body oxygen consumption, arm muscle electrical activity, arm-force and power output, respectively, were obtained in the mock-up scanner. The mean gross mechanical efficiency of execution of the ACT significantly increased 1.5-fold from 5.7 ± 1.2% to 8.6 ± 1.7% (P<0.05) after training, respectively. However, in only one subject this improvement was associated with recruitment of strictly oxidative motor units in the working biceps muscle. In all other subjects, biceps pH fell below 6.8 during exercise indicating recruitment of anaerobic motor units, the magnitude of which was either unaffected (two subjects) or even increased (two subjects) post-training. Surface electromyography and mechanical force recordings revealed that individuals employed various arm muscle recruitment strategies, using either predominantly elbow flexor muscles (two subjects), elbow extensor muscles (one subject,) or a combination of the two (two subjects), respectively. Three weeks of training improved muscle coordination but did not alter individual strategies. Conclusions: The new platform has produced the first ever in vivo dynamic data on human biceps energy and pH balance during upper body exercise. It allows evaluation of cyclic motor performance and outcomes of upper-body training regimens in healthy novices by integrating these new measurements with whole body calorimetry, surface electromyography and biomechanical measurements. This methodology may be equally valid for lower-limb impaired athletes, wheelchair users and patients with debilitating muscle disease.

Hepatic sugar phosphate levels reflect gluconeogenesis in lung cancer: simultaneous turnover measurements and 31P magnetic resonance spectroscopy in vivo

2000 ◽  
Vol 98 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Susanne LEIJ-HALFWERK ◽  
Pieter C. DAGNELIE ◽  
J. Willem O. VAN DEN BERG ◽  
J. H. Paul WILSON ◽  
Paul E. SIJENS
Keyword(s):  
Lung Cancer ◽  
Weight Loss ◽  
Magnetic Resonance ◽  
Cancer Patients ◽  
Healthy Subjects ◽  
Whole Body ◽  
Glucose Turnover ◽  
Lung Cancer Patients ◽  
Gluconeogenesis From Alanine

Stable-isotope tracers were used to assess whether levels of phosphomonoesters (PME) and phosphodiesters (PDE) in the livers of lung cancer patients, as observed by 31P magnetic resonance (MR) spectroscopy, reflect elevated whole-body glucose turnover and gluconeogenesis from alanine. Patients with advanced non-small-cell lung cancer without liver metastases (n = 24; weight loss 0–24%) and healthy control subjects (n = 13) were studied after an overnight fast. 31P MR spectra of the liver in vivo were obtained, and glucose turnover and gluconeogenesis from alanine were determined simultaneously using primed-constant infusions of [6,6-2H2]glucose and [3-13C]alanine. Liver PME concentrations were 6% higher in lung cancer patients compared with controls (not significant); PME levels in patients with ⩾ 5% weight loss were significantly higher than in patients with < 5% weight loss (P < 0.01). PDE levels did not differ between the groups. In lung cancer patients, whole-body glucose production was 19% higher (not significant) and gluconeogenesis from alanine was 42% higher (P < 0.05) compared with healthy subjects; turnover rates in lung cancer patients with ⩾ 5% weight loss were significantly elevated compared with both patients with < 5% weight loss and healthy subjects (P < 0.05). PME levels were significantly correlated with glucose turnover and gluconeogenesis from alanine in lung cancer patients (r = 0.48 and r = 0.48 respectively; P < 0.05). In conclusion, elevated PME levels in lung cancer patients appear to reflect increased glucose flux and gluconeogenesis from alanine. These results are consistent with the hypothesis that elevated PME levels are due to contributions from gluconeogenic intermediates.

Whole-Body Magnetic Resonance Imaging in Skeletal Muscle Disease

2010 ◽  
Vol 14 (01) ◽  
pp. 047-056 ◽  
Author(s):  
Martin Shelly ◽  
Ferdia Bolster ◽  
Paul Foran ◽  
Ian Crosbie ◽  
Eoin Kavanagh ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Skeletal Muscle ◽  
Magnetic Resonance ◽  
Muscle Disease ◽  
Whole Body ◽  
Resonance Imaging ◽  
Body Magnetic Resonance Imaging

The Use of Magnetic Resonance Imaging to Estimate the Mass of the Pectoralis Muscle of Chickens In Vivo

1994 ◽  
Vol 1994 ◽  
pp. 50-50
Author(s):  
N.D. Scollan ◽  
L.J. Caston ◽  
Z. Liu ◽  
A.K. Zubair ◽  
S. Leeson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Broiler Chickens ◽  
Animal Studies ◽  
Whole Body ◽  
Imaging Method ◽  
Resonance Imaging ◽  
Body Images ◽  
Tissue Samples

In studies of animal growth it is often necessary to assess whole body composition or organ size prior to and during the course of a particular treatment. Nuclear Magnetic Resonance (NMR) offers the possibility to achieve these measurements on the same animal and in a non-invasive fashion. The use of NMR in attaining body images, referred to as Magnetic Resonance Imaging (MRI), has developed as the imaging method of choice for humans, due to its excellent soft tissue contrast and use of nonionizing radiation. The use of NMR in animal studies has been limited, which is probably related to the availability of suitable facilities and the cost of using them. However, several research groups have applied it to determining fat and water content of tissue samples and intact animals (Mitchell et al., 1991; Scollan et al., 1993). The aim of this study was to evaluate the use of MRI to determine the size (volume) and shape of the Pectoralis muscle (Pectoralis major and minor) in broiler chickens, non-invasively and in vivo.

scholarly journals Noninvasive Measurements of Human Brain Temperature Using Volume-Localized Proton Magnetic Resonance Spectroscopy

1997 ◽  
Vol 17 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Ron Corbett ◽  
Abbot Laptook ◽  
Paul Weatherall
Keyword(s):  
Magnetic Resonance ◽  
Frontal Lobe ◽  
Mr Spectroscopy ◽  
Brain Temperature ◽  
Human Subjects ◽  
Normal Subjects ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Noninvasive Measurements

Elucidation of the role of cerebral hyperthermia as a secondary factor that worsens outcome after brain injury, and the therapeutic application of modest brain hypothermia would benefit from noninvasive measurements of absolute brain temperature. The present study was performed to evaluate the feasibility of using 1H magnetic resonance (MR) spectroscopy to measure absolute brain temperature in human subjects on a clinical imaging spectroscopy system operating at a field strength of 1.5 T. In vivo calibration results were obtained from swine brain during whole-body heating and cooling, with concurrent measurements of brain temperature via implanted probes. Plots of the frequency differences between the in vivo MR peaks of water and N-acetyl-aspartate and related compounds (NAX), or water and choline and other trimethylamines versus brain temperature were linear over the temperature range studied (28–40°C). These relationships were used to estimate brain temperature from 1H MR spectra obtained from 10 adult human volunteers from 4 cm3-volumes selected from the frontal lobe and thalamus. Oral and forehead temperatures were monitored concurrently with MR data collection to verify normothermia in all the subjects studied. Temperatures determined using N-acetyl-aspartate or choline as the chemical shift reference did not differ significantly, and therefore results from these estimates were averaged. The brain temperature (mean ± SD) measured from the frontal lobe (37.2 = 0.6°C) and thalamus (37.7 ± 0.6°C) were significantly different from each other (paired t-test, p = 0.035). We conclude that 1H MR spectroscopy provides a viable noninvasive means of measuring regional brain temperatures in normal subjects and is a promising approach for measuring temperatures in brain-injured subjects.

scholarly journals Advanced MRI Techniques for Muscle Imaging

2017 ◽  
Vol 21 (04) ◽  
pp. 459-469 ◽  
Author(s):  
Doris Leung ◽  
Darryl Sneag ◽  
Filippo Grande ◽  
John Carrino ◽  
Vivek Kalia
Keyword(s):  
Magnetic Resonance ◽  
Fatty Infiltration ◽  
Sampling Bias ◽  
Disease Diagnosis ◽  
Quantitative Mri ◽  
Muscle Disease ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Capillary Perfusion ◽  
Complete Evaluation

AbstractAdvanced magnetic resonance imaging (MRI) techniques can evaluate a wide array of muscle pathologies including acute or chronic muscle injury, musculotendinous response to injury, intramuscular collections and soft tissue masses, and others. In recent years, MRI has played a more important role in muscle disease diagnosis and monitoring. MRI provides excellent spatial and contrast resolution and helps direct optimal sites for muscle biopsy. Whole-body MRI now helps identify signature patterns of muscular involvement in large anatomical regions with relative ease. Quantitative MRI has advanced the evaluation and disease tracking of muscle atrophy and fatty infiltration in entities such as muscular dystrophies. Multivoxel magnetic resonance spectroscopy (MRS) now allows a more thorough, complete evaluation of a muscle of interest without the inherent sampling bias of single-voxel MRS or biopsy. Diffusion MRI allows quantification of muscle inflammation and capillary perfusion as well as muscle fiber tracking.

Lymphocyte Protein Synthesis In Vivo: a Measure of Activation

1994 ◽  
Vol 86 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Kenneth G. M. Park ◽  
Steven D. Heys ◽  
Margaret A. McNurlan ◽  
Peter J. Garlick ◽  
Oleg Eremin
Keyword(s):  
Colorectal Cancer ◽  
Protein Synthesis ◽  
Healthy Subjects ◽  
Interleukin 2 ◽  
Lymphocyte Activation ◽  
Whole Body ◽  
Thymidine Uptake ◽  
Recombinant Interleukin 2 ◽  
Median Rate

1. The ‘flooding’ dose technique was used to measure rates of lymphocyte protein synthesis after infusion of [1-13C]leucine (20 atoms% enrichment, 4 g/70 kg body weight). Lymphocyte protein synthesis was measured in healthy subjects and in patients with metastatic colorectal cancer before and during infusion of recombinant interleukin-2. Rates of protein synthesis were compared with thymidine uptake in vitro and phenotypic analysis of lymphocytes. 2. The median rate of lymphocyte protein synthesis in four healthy subjects was 9% (range 7.2–11.4%/day) and in seven patients with colorectal cancer was 6.4% (range 4.2–8.2%/day). After recombinant interleukin-2 treatment the median rate of lymphocyte protein synthesis was 27.8% (range 25.2–33.7%/day). 3. The increased rates of lymphocyte protein synthesis in vivo, after recombinant interleukin-2 infusion, corresponded with increased rates of thymidine uptake and changes in the phenotypic expression of lymphocytes, but these were less consistent than the measured rates of protein synthesis. 4. It is concluded that lymphocyte activation is accompanied by a marked increase in lymphocytic protein synthesis which may have important implications for whole body protein metabolism. Furthermore, measurement of lymphocyte protein synthesis may provide a determination of lymphocyte activation in vivo.

Ascorbic acid, a vitamin, is observed by in vivo13C nuclear magnetic resonance spectroscopy of rat liver

1998 ◽  
Vol 274 (1) ◽  
pp. E65-E71 ◽  
Author(s):  
Ekkehard Küstermann ◽  
Joachim Seelig ◽  
Basil Künnecke
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Ascorbic Acid ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Rat Liver ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
C Nmr ◽  
Nuclear Magnetic

The first in vivo detection of a vitamin with nuclear magnetic resonance (NMR) is reported for mammalian liver. Vitamin C, also known as ascorbic acid, was monitored noninvasively in rat liver by “whole body”13C NMR spectroscopy at high field after infusion of [1,2-13C2]glucose into anesthetized rats. Generally, the carbon resonances of ascorbic acid overlap with those of other highly abundant cellular metabolites, thus precluding their observation in situ. This problem was resolved by taking advantage of the13C-13C spin couplings introduced by the two covalently bound13C nuclei in [1,2-13C2]glucose. During glucose metabolism, [5,6-13C2]ascorbic acid was synthesized, which also exhibited characteristic13C homonuclear spin couplings. This feature enabled the spectral discrimination of ascorbic acid from overlapping singlet resonances of other metabolites. Quantitative analysis of the spin-coupling patterns provided an estimate of the turnover rate of hepatic ascorbic acid in vivo (1.9 ± 0.4 nmol ⋅ min−1 ⋅ g−1) and a novel approach toward a better understanding of optimal ascorbic acid requirements in humans. The results obtained in vivo were confirmed with high-resolution proton and13C NMR spectroscopy of liver extracts.

Artifacts by Misalignment of Cardiac Magnetic Resonance Phased-array Coil Elements: From Simulation to In vivo Test

2019 ◽  
Vol 15 (3) ◽  
pp. 301-307
Author(s):  
Daniele De Marchi ◽  
Alessandra Flori ◽  
Nicola Martini ◽  
Giulio Giovannetti
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Phased Array ◽  
Signal To Noise Ratio ◽  
Whole Body ◽  
Signal To Noise ◽  
Phased Array Coil ◽  
Noise Ratio ◽  
Array Coil

Background: Cardiac magnetic resonance evaluations generally require a radiofrequency coil setup comprising a transmit whole-body coil and a receive coil. In particular, radiofrequency phased-array coils are employed to pick up the signals emitted by the nuclei with high signal-tonoise ratio and a large region of sensitivity. Methods: Literature discussed different technical issues on how to minimize interactions between array elements and how to combine data from such elements to yield optimum Signal-to-Noise Ratio images. However, image quality strongly depends upon the correct coil position over the heart and of one array coil portion with respect to the other. Results: In particular, simple errors in coil positioning could cause artifacts carrying to an inaccurate interpretation of cardiac magnetic resonance images. Conclusion: This paper describes the effect of array elements misalignment, starting from coil simulation to cardiac magnetic resonance acquisitions with a 1.5 T scanner. </P><P> Phased-array coil simulation was performed using the magnetostatic approach; moreover, phantom and in vivo experiments with a commercial 8-elements cardiac phased-array receiver coil permitted to estimate signal-to-noise ratio and B1 mapping for aligned and shifted coil.

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