Fast imaging of phosphocreatine in the normal human myocardium using a three‐dimensional RARE pulse sequence at 4 Tesla

Greenman, Robert L.; Axel, Leon; Ferrari, Victor A.; Lenkinski, Robert E.

doi:10.1002/jmri.10081

Cited by 18 publications

(16 citation statements)

References 33 publications

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“…A transaxial imaging plane was prescribed through the metatarsal head region of the foot. Separate images of PCr and Pi cellular metabolites were acquired using a rapid acquisition with relaxation enhancement (RARE) pulse sequence with chemical selectivity capabilities (7). The PCr and Pi images were acquired simultaneously in a single 6-min scan.…”

Section: Methodsmentioning

confidence: 99%

Foot Muscle Energy Reserves in Diabetic Patients Without and With Clinical Peripheral Neuropathy

et al. 2009

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OBJECTIVETo investigate changes in the foot muscle energy reserves in diabetic non-neuropathic and neuropathic patients.RESEARCH DESIGN AND METHODSWe measured the phosphocreatinine (PCr)/inorganic phosphate (Pi) ratio, total 31P concentration, and the lipid/water ratio in the muscles in the metatarsal head region using MRI spectroscopy in healthy control subjects and non-neuropathic and neuropathic diabetic patients.RESULTSThe PCr/Pi ratio was higher in the control subjects (3.23 ± 0.43) followed by the non-neuropathic group (2.61 ± 0.36), whereas it was lowest in the neuropathic group (0.60 ± 1.02) (P < 0.0001). There were no differences in total 31P concentration and lipid/water ratio between the control and non-neuropathic groups, but both measurements were different in the neuropathic group (P < 0.0001).CONCLUSIONSResting foot muscle energy reserves are affected before the development of peripheral diabetic neuropathy and are associated with the endothelial dysfunction and inflammation.

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Section: Methodsmentioning

confidence: 99%

Foot Muscle Energy Reserves in Diabetic Patients Without and With Clinical Peripheral Neuropathy

et al. 2009

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“…Such techniques, however, are inherently slow and require careful repositioning of the coil for the acquisition of both the anterior and posterior areas of the muscles. Compared to chemical shift imaging, spectrally selective 31 P imaging sequences (22–27) can increase the temporal resolution of the PCr measurement when studying the dynamics of muscle recovery, following a single repetition of the exercise experiment (28, 29). Previously, we have demonstrated that imaging the entire volume of the lower leg is feasible both at 3 and 7 T with significantly improved spatial resolution (4.2 and 1.6 mL, respectively) and temporal resolution of 24 s per three‐dimensional (3D) dataset (30).…”

Section: Introductionmentioning

confidence: 99%

Why are pretreatment prostate‐specific antigen levels and biochemical recurrence poor predictors of prostate cancer survival?

Denham

Steigler

Wilcox

et al. 2009

Cancer

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An ultra scale‐down (USD) device that provides insight of how industrial homogenization impacts bioprocess performance is desirable in the biopharmaceutical industry, especially at the early stage of process development where only a small quantity of material is available. In this work, we assess the effectiveness of focused acoustics as the basis of an USD cell disruption method to mimic and study high‐pressure, step‐wise homogenization of rec Escherichia coli cells for the recovery of an intracellular protein, antibody fragment (Fab′). The release of both Fab′ and of overall protein follows first‐order reaction kinetics with respect to time of exposure to focused acoustics. The rate constant is directly proportional to applied electrical power input per unit volume. For nearly total protein or Fab′ release (>99%), the key physical properties of the disruptate produced by focused acoustics, such as cell debris particle size distribution and apparent viscosity show good agreement with those for homogenates produced by high‐pressure homogenization operated to give the same fractional release. The only key difference is observed for partial disruption of cells where focused acoustics yields a disruptate of lower viscosity than homogenization, evidently due to a greater extent of polynucleic acids degradation. Verification of this USD approach to cell disruption by high‐pressure homogenization is achieved using USD centrifugation to demonstrate the same sedimentation characteristics of disruptates prepared using both the scaled‐down focused acoustic and the pilot‐scale homogenization methods for the same fraction of protein release. Biotechnol. Bioeng. 2012; 109:2059–2069. © 2012 Wiley Periodicals, Inc.

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“…Abnormal Pi:PCr ratios have been associated with diseases that affect the muscle tissue of the extremities (2, 3, 5, 7). The rapid acquisition with relaxation enhancement (RARE) (8) pulse sequence allows the acquisition of many spin echoes during each TR period, making it well suited to the imaging of tissues or molecules with long T 1 and T 2 relaxation times such as the myocellular Pi and PCr (9–12). Methods for creating PCr images using the RARE sequence have been proposed.…”

Section: Inroductionmentioning

confidence: 99%

“…Furthermore, these methods can only be used to acquire images of a single 31 P moiety with each scan. More recently PCr images of the human myocardium and skeletal muscle have been acquired using the RARE sequence with a chemical-shift selective excitation pulse (12). While PCr images of muscle can be used to identify regions of necrosis, they lack the sensitivity of Pi:PCr ratio maps to measure subtle changes that can occur as diseases progress (1–3, 5–7).…”

Section: Inroductionmentioning

confidence: 99%

Simultaneous acquisition of phosphocreatine and inorganic phosphate images for Pi:PCr ratio mapping using a RARE sequence with chemically selective interleaving

Greenman

Wang

Smithline

2011

Magnetic Resonance Imaging

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The ratio of inorganic phosphate (Pi) to phosphocreatine (PCr) is validated marker of mitochondrial function in human muscle. The MRI rapid acquisition with relaxation enhancement (RARE) pulse sequence can acquire phosphorus-31 (31P) images with higher spatial and temporal resolution than traditional spectroscopic methods, which can then be used to create Pi:PCr ratio maps of muscle regions. While the 31P RARE method produces images that reflect the content of the 31P metabolites, it has been limited to producing an image of only one chemical shift in a scan. This increases the scan time required to acquire images of multiple chemical shifts as well as the likelihood of generating inaccurate Pi:PCr maps due to gross motion. This work is a preliminary study to demonstrate the feasibility of acquiring Pi and PCr images in a single scan by interleaving Pi and PCr chemical shift acquisitions using a chemically selective RF excitation pulse. The chemical selectivity of the excitation pulse is evaluated and Pi:PCr maps generated using the interleaved Pi and PCr acquisition method with the subject at rest and during exercise are compared to those generated using separate Pi and PCr acquisition scans. A paired t-test indicated that the resulting Pi:PCr ratios for the exercised forearm muscle regions were not significantly different between the separate Pi and PCr acquisition method (3.18 ± 1.53) (mean ± standard deviation) and the interleaved acquisition method (3.41 ± 1.66). This work demonstrates the feasibility of creating Pi:PCr ratio maps in human muscle with Pi and PCr images acquired simultaneously by interleaving between the Pi and PCr resonances in a single scan.

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Fast imaging of phosphocreatine in the normal human myocardium using a three‐dimensional RARE pulse sequence at 4 Tesla

Cited by 18 publications

References 33 publications

Foot Muscle Energy Reserves in Diabetic Patients Without and With Clinical Peripheral Neuropathy

Foot Muscle Energy Reserves in Diabetic Patients Without and With Clinical Peripheral Neuropathy

Why are pretreatment prostate‐specific antigen levels and biochemical recurrence poor predictors of prostate cancer survival?

Simultaneous acquisition of phosphocreatine and inorganic phosphate images for Pi:PCr ratio mapping using a RARE sequence with chemically selective interleaving

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