Localized semi-LASER dynamic 31P magnetic resonance spectroscopy of the soleus during and following exercise at 7 T

Fiedler, G.; Meyerspeer, Martin; Schmid, A.; Goluch, Sigrun; Schewzow, Kiril; Laistler, Elmar; Mirzahosseini, Arash; Niess, Fabian; Unger, Ewald; Wolzt, Michael; Moser, Ewald

doi:10.1007/s10334-015-0484-5

Cited by 23 publications

(32 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Muscle energetics was evaluated by NMR spectroscopy measurements on a 9.4 T scanner (Bruker BioSpec) using a volume coil for RF transmission and a 31P coil for reception 27 . In vivo imaging was conducted in a custom-made 1H/31P transceiver coil array.…”

Section: Methodsmentioning

confidence: 99%

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

et al. 2017

View full text Add to dashboard Cite

Although cellular therapies represent a promising strategy for a number of conditions, current approaches face major translational hurdles, including limited cell sources and the need for cumbersome pre-processing steps (for example, isolation, induced pluripotency)1–6. In vivo cell reprogramming has the potential to enable more-effective cell-based therapies by using readily available cell sources (for example, fibroblasts) and circumventing the need for ex vivo pre-processing7,8. Existing reprogramming methodologies, however, are fraught with caveats, including a heavy reliance on viral transfection9,10. Moreover, capsid size constraints and/or the stochastic nature of status quo approaches (viral and non-viral) pose additional limitations, thus highlighting the need for safer and more deterministic in vivo reprogramming methods11,12. Here, we report a novel yet simple-to-implement non-viral approach to topically reprogram tissues through a nanochannelled device validated with well-established and newly developed reprogramming models of induced neurons and endothelium, respectively. We demonstrate the simplicity and utility of this approach by rescuing necrotizing tissues and whole limbs using two murine models of injury-induced ischaemia.

show abstract

Section: Methodsmentioning

confidence: 99%

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

et al. 2017

View full text Add to dashboard Cite

show abstract

“…First the complete FAST experiment was performed at rest, and second the FAST experiment with the same parameters was performed during plantar flexion (one flexion per T R ) exercise, at the work load of approximately 20% of maximal voluntary contraction force. FAST measurements during exercise started 2 min after the onset of exercise, when the steady state of PCr depletion is typically reached (Fig. ).…”

Section: Methodsmentioning

confidence: 99%

Feasibility and repeatability of localized ³¹P‐MRS four‐angle saturation transfer (FAST) of the human gastrocnemius muscle using a surface coil at 7 T

et al. 2015

View full text Add to dashboard Cite

Phosphorus (31P) MRS, combined with saturation transfer (ST), provides non‐invasive insight into muscle energy metabolism. However, even at 7 T, the standard ST method with T 1 app measured by inversion recovery takes about 10 min, making it impractical for dynamic examinations. An alternative method, i.e. four‐angle saturation transfer (FAST), can shorten the examination time. The aim of this study was to test the feasibility, repeatability, and possible time resolution of the localized FAST technique measurement on an ultra‐high‐field MR system, to accelerate the measurement of both Pi‐to‐ATP and PCr‐to‐ATP reaction rates in the human gastrocnemius muscle and to test the feasibility of using the FAST method for dynamic measurements.We measured the exchange rates and metabolic fluxes in the gastrocnemius muscle of eight healthy subjects at 7 T with the depth‐resolved surface coil MRS (DRESS)‐localized FAST method. For comparison, a standard ST localized method was also used. The measurement time for the localized FAST experiment was 3.5 min compared with the 10 min for the standard localized ST experiment. In addition, in five healthy volunteers, Pi‐to‐ATP and PCr‐to‐ATP metabolic fluxes were measured in the gastrocnemius muscle at rest and during plantar flexion by the DRESS‐localized FAST method.The repeatability of PCr‐to‐ATP and Pi‐to‐ATP exchange rate constants, determined by the slab‐selective localized FAST method at 7 T, is high, as the coefficients of variation remained below 20%, and the results of the exchange rates measured with the FAST method are comparable to those measured with standard ST.During physical activity, the PCr‐to‐ATP metabolic flux decreased (from F CK = 8.21 ± 1.15 mM s−1 to F CK = 3.86 ± 1.38 mM s−1) and the Pi‐to‐ATP flux increased (from F ATP = 0.43 ± 0.14 mM s−1 to F ATP = 0.74 ± 0.13 mM s−1).In conclusion, we could demonstrate that measurements in the gastrocnemius muscle are feasible at rest and are short enough to be used during exercise with the DRESS‐localized FAST method at 7 T. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

show abstract

“…These processes have been investigated in several studies employing either 31 P MRS and MRI or 1 H arterial spin labeling (ASL) MRI in calf muscles during and after exercise. 1 H ASL is an approach to noninvasively assess local perfusion rates, while 31 P MRS is a well‐established method to investigate the energy metabolism in vivo.…”

Section: Introductionmentioning

confidence: 99%

Interleaved ³¹P MRS/¹H ASL for analysis of metabolic and functional heterogeneity along human lower leg muscles at 7T

Niess

Schmid

Bogner

et al. 2019

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

Purpose MR offers the unique possibility to noninvasively investigate cellular energy metabolism via 31P MRS, while blood perfusion, which provides oxygen and substrates to the tissue, is accessible by arterial spin labeling (ASL) 1H MRI. Because metabolic and hemodynamic parameters are linked, it would be desirable to study them simultaneously. A 3D‐resolved method is presented that allows such measurements with high spatiotemporal resolution and has the potential to discern differences along an exercising muscle. Methods Multi‐voxel localized 31P MRS was temporally interleaved with multi‐slice pASL 1H MRI. Phosphorus spectra were collected from two adjacent positions in gastrocnemius medialis (GM) during rest, submaximal plantar flexion exercise and recovery, while perfusion and T2*‐weighted axial images were acquired at the same time. Seventeen healthy volunteers (9 f / 8 m) were studied at 7 T. Results An increase of postexercise perfusion and T2*‐weighted signal in GM positively correlated with end‐exercise PCr depletion and pH drop. At proximal positions functional and metabolic activity was higher than distally, that is, perfusion increase and peak T2*‐weighted signal, end‐exercise PCr depletion, end‐exercise pH, and PCr recovery time constant were significantly different. An NOE‐induced SNR increase of approximately 20 % (P < .001), at rest, was found in interleaved 31P spectra, when comparing to 31P‐only acquisitions. Conclusions A technique for fast, simultaneous imaging of muscle functional heterogeneity in ASL, T2* and acquisition of time‐resolved 31P MRS data is presented. These single exercise recovery experiments can be used to investigate local variations during disease progression in patients suffering from vascular or muscular diseases.

show abstract

Localized semi-LASER dynamic 31P magnetic resonance spectroscopy of the soleus during and following exercise at 7 T

Cited by 23 publications

References 32 publications

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

Feasibility and repeatability of localized ³¹P‐MRS four‐angle saturation transfer (FAST) of the human gastrocnemius muscle using a surface coil at 7 T

Interleaved ³¹P MRS/¹H ASL for analysis of metabolic and functional heterogeneity along human lower leg muscles at 7T

Contact Info

Product

Resources

About

Localized semi-LASER dynamic 31P magnetic resonance spectroscopy of the soleus during and following exercise at 7 T

Cited by 23 publications

References 32 publications

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

Topical tissue nano-transfection mediates non-viral stroma reprogramming and rescue

Feasibility and repeatability of localized 31P‐MRS four‐angle saturation transfer (FAST) of the human gastrocnemius muscle using a surface coil at 7 T

Interleaved 31P MRS/1H ASL for analysis of metabolic and functional heterogeneity along human lower leg muscles at 7T

Contact Info

Product

Resources

About

Feasibility and repeatability of localized ³¹P‐MRS four‐angle saturation transfer (FAST) of the human gastrocnemius muscle using a surface coil at 7 T

Interleaved ³¹P MRS/¹H ASL for analysis of metabolic and functional heterogeneity along human lower leg muscles at 7T