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Kemp GJ. Editorial for "Quantitative Assessment of Peripheral Oxidative Metabolism With a New Dynamic 1H MRI: A Pilot Study in People With and Without Diabetes Mellitus". J Magn Reson Imaging 2024; 60:220-221. [PMID: 37655836 DOI: 10.1002/jmri.28993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 09/02/2023] Open
Affiliation(s)
- Graham J Kemp
- Department of Musculoskeletal and Ageing Science, University of Liverpool, Liverpool, UK
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2
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Dynamic 31P-MRI and 31P-MRS of lower leg muscles in heart failure patients. Sci Rep 2021; 11:7412. [PMID: 33795721 PMCID: PMC8016929 DOI: 10.1038/s41598-021-86392-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/15/2021] [Indexed: 11/29/2022] Open
Abstract
Impaired oxidative metabolism is one of multi-variate factors leading to exercise intolerance in heart failure patients. The purpose of the study was to demonstrate the use of dynamic 31P magnetic resonance spectroscopy (MRS) and 31P magnetic resonance imaging (MRI) techniques to measure PCr resynthesis rate post-exercise as a biomarker for oxidative metabolism in skeletal muscle in HF patients and controls. In this prospective imaging study, we recruited six HF patients and five healthy controls. The imaging protocol included 31P-MRS, spectrally selective 3D turbo spin echo for 31P-MRI, and Dixon multi-echo GRE for fat–water imaging on a 3 T clinical MRI scanner. All the subjects were scanned pre-exercise, during plantar flexion exercise, and post-exercise recovery, with two rounds of exercise for 31P -MRS and 31P-MRI, respectively. Unpaired t-tests were used to compare 31P-MRS and 31P-MRI results between the HF and control cohorts. The results show that PCr resynthesis rate was significantly slower in the HF cohort compared to the controls using 31P-MRS (P = 0.0003) and 31P-MRI (P = 0.0014). 31P-MRI showed significant differences between the cohorts in muscle groups (soleus (P = 0.0018), gastrocnemius lateral (P = 0.0007) and gastrocnemius medial (P = 0.0054)). The results from this study suggest that 31P-MRS/31P-MRI may be used to quantify lower leg muscle oxidative metabolism in HF patients, with 31P-MRI giving an additional advantage of allowing further localization of oxidative metabolism deficits. Upon further validation, these techniques may serve as a potentially useful clinical imaging biomarker for staging and monitoring therapies in HF-patients.
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Santos-Díaz A, Noseworthy MD. Phosphorus magnetic resonance spectroscopy and imaging (31P-MRS/MRSI) as a window to brain and muscle metabolism: A review of the methods. Biomed Signal Process Control 2020. [DOI: 10.1016/j.bspc.2020.101967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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4
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Abstract
In this article, an overview of the current developments and research applications for non-proton magnetic resonance imaging (MRI) at ultrahigh magnetic fields (UHFs) is given. Due to technical and methodical advances, efficient MRI of physiologically relevant nuclei, such as Na, Cl, Cl, K, O, or P has become feasible and is of interest to obtain spatially and temporally resolved information that can be used for biomedical and diagnostic applications. Sodium (Na) MRI is the most widespread multinuclear imaging method with applications ranging over all regions of the human body. Na MRI yields the second largest in vivo NMR signal after the clinically used proton signal (H). However, other nuclei such as O and P (energy metabolism) or Cl and K (cell viability) are used in an increasing number of MRI studies at UHF. One major advancement has been the increased availability of whole-body MR scanners with UHFs (B0 ≥7T) expanding the range of detectable nuclei. Nevertheless, efforts in terms of pulse sequence and post-processing developments as well as hardware designs must be made to obtain valuable information in clinically feasible measurement times. This review summarizes the available methods in the field of non-proton UHF MRI, especially for Na MRI, as well as introduces potential applications in clinical research.
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Affiliation(s)
- Sebastian C Niesporek
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Tanja Platt
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Liu Y, Gu Y, Yu X. Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review. Quant Imaging Med Surg 2017; 7:707-726. [PMID: 29312876 PMCID: PMC5756783 DOI: 10.21037/qims.2017.11.03] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/11/2017] [Indexed: 01/11/2023]
Abstract
Many human diseases are caused by an imbalance between energy production and demand. Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 (31P) MRS/MRI. Furthermore, 31P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase. However, a major impediment for the clinical applications of 31P-MRS/MRI is the prohibitively long acquisition time and/or the low spatial resolution that are necessary to achieve adequate signal-to-noise ratio. In this review, current 31P-MRS/MRI techniques used in basic science and clinical research are presented. Recent advances in the development of fast 31P-MRS/MRI methods are also discussed.
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Affiliation(s)
- Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, USA
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Iterative reconstruction of radially-sampled 31 P bSSFP data using prior information from 1 H MRI. Magn Reson Imaging 2017; 37:147-158. [DOI: 10.1016/j.mri.2016.11.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 10/10/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022]
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7
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Valkovič L, Chmelík M, Krššák M. In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism. Anal Biochem 2017; 529:193-215. [PMID: 28119063 PMCID: PMC5478074 DOI: 10.1016/j.ab.2017.01.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 01/18/2023]
Abstract
In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.
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Affiliation(s)
- Ladislav Valkovič
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Oxford, United Kingdom; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia.
| | - Marek Chmelík
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Institute for Clinical Molecular MRI in Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria
| | - Martin Krššák
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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8
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Skeletal muscle ATP synthesis and cellular H(+) handling measured by localized (31)P-MRS during exercise and recovery. Sci Rep 2016; 6:32037. [PMID: 27562396 PMCID: PMC4999956 DOI: 10.1038/srep32037] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/02/2016] [Indexed: 11/09/2022] Open
Abstract
(31)P magnetic resonance spectroscopy (MRS) is widely used for non-invasive investigation of muscle metabolism dynamics. This study aims to extend knowledge on parameters derived from these measurements in detail and comprehensiveness: proton (H(+)) efflux, buffer capacity and the contributions of glycolytic (L) and oxidative (Q) rates to ATP synthesis were calculated from the evolutions of phosphocreatine (PCr) and pH. Data are reported for two muscles in the human calf, for each subject and over a wide range of exercise intensities. 22 subjects performed plantar flexions in a 7T MR-scanner, leading to PCr changes ranging from barely noticeable to almost complete depletion, depending on exercise protocol and muscle studied by localized MRS. Cytosolic buffer capacity was quantified for the first time non-invasively and individually, as was proton efflux evolution in early recovery. Acidification started once PCr depletion reached 60-75%. Initial and end-exercise L correlated with end-exercise levels of PCr and approximately linear with pH. Q calculated directly from PCr and pH derivatives was plausible, requiring fewer assumptions than the commonly used ADP-model. In conclusion, the evolution of parameters describing cellular energy metabolism was measured over a wide range of exercise intensities, revealing a relatively complete picture of muscle metabolism.
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Lin YC, Wu J, Baltzis D, Veves A, Greenman RL. MRI assessment of regional differences in phosphorus-31 metabolism and morphological abnormalities of the foot muscles in diabetes. J Magn Reson Imaging 2016; 44:1132-1142. [PMID: 27080459 DOI: 10.1002/jmri.25278] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/29/2016] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To assess differences in the phosphorus-31 (31 P) metabolism and morphology in multiple muscle regions in the forefoot of diabetic patients and normal subjects. MATERIALS AND METHODS Fifteen diabetic patients and 15 normal subjects were assessed for muscle atrophy by 1 H magnetic resonance imaging (MRI) at 3T to grade the flexor hallucis, adductor hallucis, interosseous regions, and entire foot cross-section. Each region and the entire foot were also quantitatively evaluated for metabolic function using 31 P imaging for spatial mapping of the inorganic phosphate (Pi) to phosphocreatine (PCr) ratio (Pi/PCr). The ratio of viable muscle area to the predefined region areas (31 P/1 H) was calculated. The variability of each method was assessed by its coefficient of variation (CV). RESULTS Muscle atrophy was significantly more severe in diabetic compared to normal subjects in all regions (P < 0.01). The 31 P/1 H area ratio was significantly larger in the adductor hallucis than in the other two regions (P < 0.05). The Pi/PCr ratio was significantly different between the two groups in the flexor hallucis and interosseous regions (P < 0.05) but not adductor hallucis region. The CV for Pi/PCr ranged from 10.13 to 55.84, while it ranged from 73.40 to 263.90 for qualitative grading. CONCLUSION Changes in atrophy and metabolism appear to occur unequally between different regions of the forefoot in diabetes. The adductor hallucis region appears more capable of maintaining structural and metabolic integrity than the flexor hallucis or interosseous regions. The CV analysis suggests that the quantitative 31 P methods have less variability than the qualitative grading. J. Magn. Reson. Imaging 2016;44:1132-1142.
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Affiliation(s)
- Yu-Ching Lin
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School,Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Keelung and Chang Gung University, Taiwan
| | - Jim Wu
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School
| | - Dimitrios Baltzis
- Microcirculation Laboratory and Joslin‐Beth Israel Deaconess Foot Center, the Beth Israel Deaconess Medical Center
| | - Aristidis Veves
- Microcirculation Laboratory and Joslin‐Beth Israel Deaconess Foot Center, the Beth Israel Deaconess Medical Center
| | - Robert L Greenman
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School,RLG Scientific, Millis. MA
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10
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Rink K, Berger MC, Korzowski A, Breithaupt M, Biller A, Bachert P, Nagel AM. Nuclear-Overhauser-enhanced MR imaging of (31)P-containing metabolites: multipoint-Dixon vs. frequency-selective excitation. Magn Reson Imaging 2015; 33:1281-1289. [PMID: 26248272 DOI: 10.1016/j.mri.2015.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 07/31/2015] [Indexed: 01/01/2023]
Abstract
The purpose of this study is to develop nuclear-Overhauser-enhanced (NOE) [(1)H]-(31)P magnetic resonance imaging (MRI) based on 3D fully-balanced steady-state free precession (fbSSFP). Therefore, two implementations of a 3D fbSSFP sequence are compared using frequency-selective excitation (FreqSel) and multipoint-Dixon (MP-Dixon). (31)P-containing model solutions and four healthy volunteers were examined at field strengths of B0=3T and 7T. Maps of the distribution of phosphocreatine (PCr), inorganic phosphate (Pi), and adenosine 5´-triphosphate (ATP) in the human calf were obtained with an isotropic resolution of 1.5cm (1.0cm) in an acquisition time of 5min (10min). NOE-pulses had the highest impact on the PCr acquisitions enhancing the signal up to (82 ± 13) % at 3T and up to (37 ± 9) % at 7T. An estimation of the level of PCr in muscle tissue from [(1)H]-(31)P MRI data yielded a mean value of (33 ± 8) mM. In conclusion, direct [(1)H]-(31)P imaging using FreqSel as well as MP-Dixon is possible in clinically feasible acquisition times. FreqSel should be preferred for measurements where only a single metabolite resonance is considered. MP-Dixon performs better in terms of SNR if a larger spectral width is of interest.
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Affiliation(s)
- Kristian Rink
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Moritz C Berger
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andreas Korzowski
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mathies Breithaupt
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin Biller
- Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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11
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Schmid AI, Meyerspeer M, Robinson SD, Goluch S, Wolzt M, Fiedler GB, Bogner W, Laistler E, Krššák M, Moser E, Trattnig S, Valkovič L. Dynamic PCr and pH imaging of human calf muscles during exercise and recovery using (31) P gradient-Echo MRI at 7 Tesla. Magn Reson Med 2015; 75:2324-31. [PMID: 26115021 DOI: 10.1002/mrm.25822] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/15/2015] [Accepted: 06/01/2015] [Indexed: 12/26/2022]
Abstract
PURPOSE Simultaneous acquisition of spatially resolved (31) P-MRI data for evaluation of muscle specific energy metabolism, i.e., PCr and pH kinetics. METHODS A three-dimensional (3D) gradient-echo sequence for multiple frequency-selective excitations of the PCr and Pi signals in an interleaved sampling scheme was developed and tested at 7 Tesla (T). The pH values were derived from the chemical shift-induced phase difference between the resonances. The achieved spatial resolution was ∼2 mL with image acquisition time below 6 s. Ten healthy volunteers were studied performing plantar flexions during the delay between (31) P-MRI acquisitions, yielding a temporal resolution of 9-10 s. RESULTS Signal from anatomically matched regions of interest had sufficient signal-to-noise ratio to allow single-acquisition PCr and pH quantification. The Pi signal was clearly detected in voxels of actively exercising muscles. The PCr depletions were in gastrocnemius 42 ± 14% (medialis), 48 ± 17% (lateralis) and in soleus 20 ± 11%. The end exercise pH values were 6.74 ± 0.18 and 6.65 ± 0.27 for gastrocnemius medialis and lateralis, respectively, and 6.96 ± 0.12 for soleus muscle. CONCLUSION Simultaneous acquisition of PCr and Pi images with high temporal resolution, suitable for measuring PCr and pH kinetics in exercise-recovery experiments, was demonstrated at 7T. This study presents a fast alternative to MRS for quantifying energy metabolism of posterior muscle groups of the lower leg. Magn Reson Med 75:2324-2331, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Albrecht Ingo Schmid
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Martin Meyerspeer
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Simon Daniel Robinson
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Sigrun Goluch
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Wolzt
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Georg Bernd Fiedler
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Bogner
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Elmar Laistler
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Martin Krššák
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria.,Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Ewald Moser
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Siegfried Trattnig
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Ladislav Valkovič
- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria.,Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria.,Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
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12
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Magland JF, Li C, Langham MC, Wehrli FW. Pulse sequence programming in a dynamic visual environment: SequenceTree. Magn Reson Med 2015; 75:257-65. [PMID: 25754837 DOI: 10.1002/mrm.25640] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/09/2014] [Accepted: 01/07/2015] [Indexed: 01/04/2023]
Abstract
PURPOSE To describe SequenceTree, an open source, integrated software environment for implementing MRI pulse sequences and, ideally, exporting them to actual MRI scanners. The software is a user-friendly alternative to vendor-supplied pulse sequence design and editing tools and is suited for programmers and nonprogrammers alike. METHODS The integrated user interface was programmed using the Qt4/C++ toolkit. As parameters and code are modified, the pulse sequence diagram is automatically updated within the user interface. Several aspects of pulse programming are handled automatically, allowing users to focus on higher-level aspects of sequence design. Sequences can be simulated using a built-in Bloch equation solver and then exported for use on a Siemens MRI scanner. Ideally, other types of scanners will be supported in the future. RESULTS SequenceTree has been used for 8 years in our laboratory and elsewhere and has contributed to more than 50 peer-reviewed publications in areas such as cardiovascular imaging, solid state and nonproton NMR, MR elastography, and high-resolution structural imaging. CONCLUSION SequenceTree is an innovative, open source, visual pulse sequence environment for MRI combining simplicity with flexibility and is ideal both for advanced users and users with limited programming experience.
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Affiliation(s)
- Jeremy F Magland
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Cheng Li
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Michael C Langham
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Felix W Wehrli
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
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13
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Zhu H, Arlinghaus LR, Whisenant JG, Li M, Gore JC, Yankeelov TE. Sequence design and evaluation of the reproducibility of water-selective diffusion-weighted imaging of the breast at 3 T. NMR IN BIOMEDICINE 2014; 27:1030-1036. [PMID: 24986756 PMCID: PMC4134406 DOI: 10.1002/nbm.3146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/02/2014] [Accepted: 05/08/2014] [Indexed: 06/03/2023]
Abstract
Diffusion measurements derived from breast MRI can be adversely affected by unwanted signals from abundant fatty tissues if they are not suppressed adequately. To minimize this undesired contribution, we designed and optimized a water-selective diffusion-weighted imaging (DWI) sequence, which relies on spectrally selective excitation on the water resonance, obviating the need for fat suppression. As this method is more complex than standard DWI methods, we also report a test-retest study to evaluate its reproducibility. In this study, a spectrally selective Gaussian pulse on water resonance was combined with a pair of slice-selective adiabatic refocusing pulses for water-only DWI. Field map-based shimming and manual determination of the center frequency were used for water selection. The selectivity of the excitation pulse was optimized by a spectrally selective spectroscopy sequence based on the same principles. A test-retest study of 10 volunteers in two separate visits was used to evaluate its reproducibility. Our results from all subjects showed high-quality diffusion-weighted images of the breast without fat contamination. Mean apparent diffusion coefficients for b = 0, 600 s/mm(2) and b = 50, 600 s/mm(2) all showed good reproducibility, as 95% confidence intervals of the apparent diffusion coefficients were 4 × 10(-5) mm(2) /s and 5 × 10(-5) mm(2) /s and repeatability values were 1.09 × 10(-4) and 1.31 × 10(-4) , respectively. In conclusion, water-selective DWI is a feasible alternative to standard methods of DWI based on fat suppression. The added complexity of the method does not compromise the reproducibility of diffusion measurements in the breast.
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Affiliation(s)
- He Zhu
- Vanderbilt University Institute of Imaging Science, Tennessee 37232
- Radiology and Radiological Sciences, Vanderbilt University Nashville, Tennessee 37232
| | - Lori R. Arlinghaus
- Vanderbilt University Institute of Imaging Science, Tennessee 37232
- Radiology and Radiological Sciences, Vanderbilt University Nashville, Tennessee 37232
| | - Jennifer G. Whisenant
- Vanderbilt University Institute of Imaging Science, Tennessee 37232
- Radiology and Radiological Sciences, Vanderbilt University Nashville, Tennessee 37232
| | - Ming Li
- Department of Biostatistics Vanderbilt University Nashville, Tennessee 37232
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science, Tennessee 37232
- Radiology and Radiological Sciences, Vanderbilt University Nashville, Tennessee 37232
- Department of Physics, Vanderbilt University Nashville, Tennessee 37232
- Department of Biomedical Engineering, Vanderbilt University Nashville, Tennessee 37232
- Department of Molecular Physiology and Biophysics, Vanderbilt University Nashville, Tennessee 37232
| | - Thomas E. Yankeelov
- Vanderbilt University Institute of Imaging Science, Tennessee 37232
- Radiology and Radiological Sciences, Vanderbilt University Nashville, Tennessee 37232
- Department of Physics, Vanderbilt University Nashville, Tennessee 37232
- Department of Biomedical Engineering, Vanderbilt University Nashville, Tennessee 37232
- Department of Cancer Biology, Vanderbilt University Nashville, Tennessee 37232
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14
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Three-dimensional saturation transfer ³¹P-MRI in muscles of the lower leg at 3.0 T. Sci Rep 2014; 4:5219. [PMID: 24910264 PMCID: PMC4048915 DOI: 10.1038/srep05219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 05/19/2014] [Indexed: 02/02/2023] Open
Abstract
The creatine kinase (CK) reaction plays a critical role in skeletal muscle function, and can be studied non-invasively using phosphorus (31P) saturation transfer (ST) techniques. However, due to the low MR sensitivity of the 31P nucleus, most studies on clinically approved magnetic fields (≤3.0 T) have been performed with coarse resolution and limited tissue coverage. However, such methods are not able to detect spatially resolved metabolic heterogeneities, which may be important in diseases of the skeletal muscle. In this study, our aim was to develop and implement a 31P-MRI method for mapping the kinetics of the CK reaction, and the unidirectional phosphocreatine (PCr) to adenosine triphosphate (ATP) metabolic fluxes in muscles of the lower leg on a clinical 3.0 T MR scanner. We imaged the lower leg muscles of ten healthy volunteers (total experimental time: 40 min, nominal voxel sizes 0.5 mL), and found statistically significant differences between the kinetics of the CK reaction among muscle groups. Our developed technique may allow in the future the early detection of focal metabolic abnormalities in diseases that affect the function of the skeletal muscle.
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15
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Parasoglou P, Xia D, Chang G, Convit A, Regatte RR. Three-dimensional mapping of the creatine kinase enzyme reaction rate in muscles of the lower leg. NMR IN BIOMEDICINE 2013; 26:1142-51. [PMID: 23436474 PMCID: PMC3744626 DOI: 10.1002/nbm.2928] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/06/2012] [Accepted: 01/07/2013] [Indexed: 05/25/2023]
Abstract
Phosphorus ((31) P) magnetization transfer (MT) techniques enable the non-invasive measurement of metabolic turnover rates of important enzyme-catalyzed reactions, such as the creatine kinase reaction (CK), a major transducing reaction involving adenosine triphosphate and phosphocreatine. Alteration in the kinetics of the CK reaction rate appears to play a central role in many disease states. In this study, we developed and implemented at ultra-high field (7T) a novel three-dimensional (31) P-MT imaging sequence that maps the kinetics of CK in the entire volume of the lower leg at relatively high resolution (0.52 mL voxel size), and within acquisition times that can be tolerated by patients (below 60 min). We tested the sequence on five healthy and two clinically diagnosed type 2 diabetic subjects. Overall, we obtained measurements that are in close agreement with measurements reported previously using spectroscopic methods. Importantly, our spatially resolved method allowed us to measure local CK reaction rate constants and metabolic fluxes in individual muscles in a non-invasive manner. Furthermore, it allowed us to detect variations of the CK rates of different muscles, which would not have been possible using unlocalized MRS methods. The results of this work suggest that 3D mapping of the CK reaction rates and metabolic fluxes can be achieved in the skeletal muscle in vivo at relatively high spatial resolution and with acquisition times well tolerated by patients. The ability to measure bioenergetics simultaneously in large areas of muscles will bring new insights into possible heterogeneous patterns of muscle metabolism associated with several diseases and serve as a valuable tool for monitoring the efficacy of interventions.
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Affiliation(s)
- Prodromos Parasoglou
- Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY 10016, USA.
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Parasoglou P, Xia D, Chang G, Regatte RR. Dynamic three-dimensional imaging of phosphocreatine recovery kinetics in the human lower leg muscles at 3T and 7T: a preliminary study. NMR IN BIOMEDICINE 2013; 26:348-56. [PMID: 23065754 PMCID: PMC3696475 DOI: 10.1002/nbm.2866] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 08/20/2012] [Accepted: 08/22/2012] [Indexed: 05/11/2023]
Abstract
The rate of phosphocreatine (PCr) resynthesis after physical exercise has been extensively studied with phosphorus (³¹P)-MRS. Previous studies have used small surface coils that were limited to measuring one superficial muscle per experiment. This study focuses on the development and implementation of a spectrally selective three-dimensional turbo spin echo (3D-TSE) sequence at 3T and 7T with temporal resolution of 24 s, using two geometrically identical volume coils. We acquired imaging data of PCr recovery from four healthy volunteers and one diabetic patient, who performed plantar flexions using resistance bands. We segmented the anatomical regions of six different muscles from the lower leg, namely the gastrocnemius [lateral (GL) and medial (GM)], the tibialis [anterior (TA) and posterior (TP)], the soleus (S) and the peroneus (P) and measured the local PCr resynthesis rate constants. During the same examination, we also acquired unlocalized (³¹P-MRS data at a temporal resolution of 6 s. At 3T, the PCr resynthesis rate constants were measured at 25.4 ± 3.7 s [n = 4, mean ± standard deviation (SD)] using the MRS method and 25.6 ± 4.4 s using the MRI method. At 7T, the measured rates were 26.4 ± 3.2 s and 26.2 ± 4.7 s for MRS and MRI. Using our imaging method, we measured the local PCr resynthesis rate constants in six individual muscles of the lower leg (min/max 20.2/31.7 ). The recovery rate constants measured for the diabetic patient were 55.5 s (MRS) and 52.7 s (MRI). The successful implementation of our 3D-method suggests that imaging is possible at both fields with a relatively high spatial resolution (voxel size: 4.2 mL at 3T and 1.6 mL at 7T) using volume coils and that local PCr resynthesis rates can be obtained in a single measurement. The advantage of the imaging method is that it can highlight differences in PCr resynthesis rates between different muscles in a single measurement in order to study spatial gradients of metabolic properties of diseased states for which very little is currently known.
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Affiliation(s)
- Prodromos Parasoglou
- Quantitative Multinuclear Musculoskeletal Imaging Group, Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA.
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Parasoglou P, Xia D, Chang G, Regatte RR. 3D-mapping of phosphocreatine concentration in the human calf muscle at 7 T: comparison to 3 T. Magn Reson Med 2013; 70:1619-25. [PMID: 23390003 DOI: 10.1002/mrm.24616] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 11/27/2012] [Accepted: 12/05/2012] [Indexed: 01/09/2023]
Abstract
PURPOSE The development and implementation of a spectrally selective 3D-Turbo Spin Echo sequence for quantitative mapping of phosphocreatine (PCr) concentration in different muscles of the lower leg of healthy volunteers both at 3 T and 7 T. METHODS Nine healthy volunteers were recruited, all of whom where scanned at 3 T and 7 T. Three dimensional PCr concentration maps were obtained after images were corrected for B1 inhomogeneities, T1 relaxation weighting, and partial volume of fatty tissue in the muscles. Two volunteers performed plantar flexions inside the magnet, and the oxidative capacity of their muscles was estimated. RESULTS Three dimensional PCr concentration maps were obtained, with full muscle coverage and nominal voxel size of 0.52 mL at both fields. At 7 T a 2.7-fold increase of signal-to-noise ratio was achieved compared to 3 T. CONCLUSION Imaging (31) P metabolites at 7 T allowed for significant increase in signal to noise ratio compared to imaging at 3 T, while quantification of the PCr concentration remained unaffected. The importance of such an increase in signal-to-noise ratio is 2-fold, first higher resolution images with reduced partial volume effects can be acquired, and second multiple measurements such as dynamic imaging of PCr post-exercise, (31) P magnetization transfer, or other (1) H measurements, can be acquired in a single imaging session.
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Affiliation(s)
- Prodromos Parasoglou
- Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, New York, USA
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Parasoglou P, Feng L, Xia D, Otazo R, Regatte RR. Rapid 3D-imaging of phosphocreatine recovery kinetics in the human lower leg muscles with compressed sensing. Magn Reson Med 2012; 68:1738-46. [PMID: 23023624 DOI: 10.1002/mrm.24484] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/09/2012] [Accepted: 08/13/2012] [Indexed: 12/30/2022]
Abstract
The rate of phosphocreatine (PCr) resynthesis following physical exercise is an accepted index of mitochondrial oxidative metabolism and has been studied extensively with unlocalized (31)P-MRS methods and small surface coils. Imaging experiments using volume coils that measure several muscles simultaneously can provide new insights into the variability of muscle function in healthy and diseased states. However, they are limited by long acquisition times relative to the dynamics of PCr recovery. This work focuses on the implementation of a compressed sensing technique to accelerate imaging of PCr resynthesis following physical exercise, using a modified three-dimensional turbo-spin-echo sequence and principal component analysis as sparsifying transform. The compressed sensing technique was initially validated using 2-fold retrospective undersampling of fully sampled data from four volunteers acquired on a 7T MRI system (voxel size: 1.6 mL, temporal resolution: 24 s), which led to an accurate estimation of the mono-exponential PCr resynthesis rate constant (mean error <6.4%). Acquisitions with prospective 2-fold acceleration (temporal resolution: 12 s) demonstrated that three-dimensional mapping of PCr resynthesis is possible at a temporal resolution that is sufficiently high for characterizing the recovery curve of several muscles in a single measurement.
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Affiliation(s)
- Prodromos Parasoglou
- Department of Radiology, Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), New York University Langone Medical Center, New York, New York 10016, USA.
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