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Preclinical MRI Using Hyperpolarized 129Xe. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238338. [PMID: 36500430 PMCID: PMC9738892 DOI: 10.3390/molecules27238338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022]
Abstract
Although critical for development of novel therapies, understanding altered lung function in disease models is challenging because the transport and diffusion of gases over short distances, on which proper function relies, is not readily visualized. In this review we summarize progress introducing hyperpolarized 129Xe imaging as a method to follow these processes in vivo. The work is organized in sections highlighting methods to observe the gas replacement effects of breathing (Gas Dynamics during the Breathing Cycle) and gas diffusion throughout the parenchymal airspaces (3). We then describe the spectral signatures indicative of gas dissolution and uptake (4), and how these features can be used to follow the gas as it enters the tissue and capillary bed, is taken up by hemoglobin in the red blood cells (5), re-enters the gas phase prior to exhalation (6), or is carried via the vasculature to other organs and body structures (7). We conclude with a discussion of practical imaging and spectroscopy techniques that deliver quantifiable metrics despite the small size, rapid motion and decay of signal and coherence characteristic of the magnetically inhomogeneous lung in preclinical models (8).
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Shepelytskyi Y, Grynko V, Rao MR, Li T, Agostino M, Wild JM, Albert MS. Hyperpolarized 129 Xe imaging of the brain: Achievements and future challenges. Magn Reson Med 2022; 88:83-105. [PMID: 35253919 PMCID: PMC9314594 DOI: 10.1002/mrm.29200] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/22/2021] [Accepted: 01/25/2022] [Indexed: 11/25/2022]
Abstract
Hyperpolarized (HP) xenon-129 (129 Xe) brain MRI is a promising imaging modality currently under extensive development. HP 129 Xe is nontoxic, capable of dissolving in pulmonary blood, and is extremely sensitive to the local environment. After dissolution in the pulmonary blood, HP 129 Xe travels with the blood flow to the brain and can be used for functional imaging such as perfusion imaging, hemodynamic response detection, and blood-brain barrier permeability assessment. HP 129 Xe MRI imaging of the brain has been performed in animals, healthy human subjects, and in patients with Alzheimer's disease and stroke. In this review, the overall progress in the field of HP 129 Xe brain imaging is discussed, along with various imaging approaches and pulse sequences used to optimize HP 129 Xe brain MRI. In addition, current challenges and limitations of HP 129 Xe brain imaging are discussed, as well as possible methods for their mitigation. Finally, potential pathways for further development are also discussed. HP 129 Xe MRI of the brain has the potential to become a valuable novel perfusion imaging technique and has the potential to be used in the clinical setting in the future.
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Affiliation(s)
- Yurii Shepelytskyi
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada
| | - Vira Grynko
- Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Chemistry and Materials Science Program, Lakehead University, Thunder Bay, Ontario, Canada
| | - Madhwesha R Rao
- POLARIS, Unit of Academic Radiology, Department of IICD, University of Sheffield, Sheffield, UK
| | - Tao Li
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada
| | - Martina Agostino
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada
| | - Jim M Wild
- POLARIS, Unit of Academic Radiology, Department of IICD, University of Sheffield, Sheffield, UK.,Insigneo Institute for in Silico Medicine, Sheffield, UK
| | - Mitchell S Albert
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada
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Wakayama T, Ueyama T, Imai F, Kimura A, Fujiwara H. Quantitative assessment of regional lung ventilation in emphysematous mice using hyperpolarized 129Xe MRI with a continuous flow hyperpolarizing system. Magn Reson Imaging 2022; 92:88-95. [PMID: 35654279 DOI: 10.1016/j.mri.2022.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Lung ventilation function in small animals can be assessed by using hyperpolarized gas MRI. For these experiments a free breathing protocol is generally preferred to mechanical ventilation as mechanical ventilation can often lead to ventilation lung injury, while the need to maintain a gas reservoir may lead to a partial reduction of the polarization. PURPOSE To evaluate regional lung ventilation of mice by a simple but fast method under free breathing and give evidence for effectiveness with an elastase instilled emphysematous mice. ANIMAL MODEL Emphysematous mice. MATERIALS AND METHODS A Look-Locker based saturation recovery sequence was developed for continuous flow hyperpolarized (CF-HP) 129Xe gas experiments, and the apparent gas-exchange rate, k', was measured by the analysis of the saturation recovery curve. RESULTS In mice with elastase-induced mild emphysema, reductions of 15-30% in k' values were observed as the results of lesion-induced changes in the lung. DATA CONCLUSION The proposed method was applied to an emphysematous model mice and ventilation dysfunctions have been approved as a definite decrease in k' values, supporting the usefulness for a non-invasive assessment of the lung functions in preclinical study by the CF-HP 129Xe experiments.
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Affiliation(s)
- Tetsuya Wakayama
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Graduate of School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tsuyoshi Ueyama
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Graduate of School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Fumito Imai
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Graduate of School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Atsuomi Kimura
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Graduate of School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hideaki Fujiwara
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Graduate of School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Shepelytskyi Y, Grynko V, Li T, Hassan A, Granberg K, Albert MS. The effects of an initial depolarization pulse on dissolved phase hyperpolarized 129 Xe brain MRI. Magn Reson Med 2021; 86:3147-3155. [PMID: 34254356 DOI: 10.1002/mrm.28918] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/01/2021] [Accepted: 06/16/2021] [Indexed: 12/27/2022]
Abstract
PURPOSE To evaluate the effect of an initial 90° depolarization RF pulse on the dissolved-phase hyperpolarized (HP) xenon-129 (129 Xe) brain imaging and to compare the SNR variability of HP 129 Xe images acquired without an initial depolarization RF pulse to those following the initial depolarization pulse. METHODS Five cognitive normal healthy volunteers were imaged using a Philips Achieva 3.0T MRI scanner during a single breath-hold following inhalation of 1 L of HP 129 Xe. Each participant underwent six HP 129 Xe scans. Three scans were performed using conventional single-slice projection HP 129 Xe brain imaging, and the other three scans were performed using the HP 129 Xe time-of-flight imaging with an initial rectangular depolarization pulse. RESULTS Although the utilization of an initial depolarization results in the reduction of the mean image SNR, the presence of an initial depolarization RF pulse reduces the SNR variability of the HP 129 Xe brain image by a factor of 2.26. The highest SNR variability was observed from the posterior brain region, where the anterior region possessed the lower level of signal variability. CONCLUSION An initial 90° depolarization RF pulse, applied prior to the HP 129 Xe image acquisition, reduced the HP 129 Xe signal variability more than two times between the different breath-hold images.
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Affiliation(s)
- Yurii Shepelytskyi
- Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada
| | - Vira Grynko
- Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Chemistry and Materials Science Program, Lakehead University, Thunder Bay, Ontario, Canada
| | - Tao Li
- Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada
| | - Ayman Hassan
- Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada
| | - Karl Granberg
- Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada
| | - Mitchell S Albert
- Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada
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Multiplexed 129Xe HyperCEST MRI Detection of Genetically Reconstituted Bacterial Protein Nanoparticles in Human Cancer Cells. CONTRAST MEDIA & MOLECULAR IMAGING 2020; 2020:5425934. [PMID: 32256252 PMCID: PMC7091528 DOI: 10.1155/2020/5425934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 01/29/2020] [Indexed: 11/17/2022]
Abstract
Gas vesicle nanoparticles (GVs) are gas-containing protein assemblies expressed in bacteria and archaea. Recently, GVs have gained considerable attention for biotechnological applications as genetically encodable contrast agents for MRI and ultrasonography. However, at present, the practical use of GVs is hampered by a lack of robust methodology for their induction into mammalian cells. Here, we demonstrate the genetic reconstitution of protein nanoparticles with characteristic bicone structures similar to natural GVs in a human breast cancer cell line KPL-4 and genetic control of their size and shape through expression of reduced sets of humanized gas vesicle genes cloned into Tol2 transposon vectors, referencing the natural gas vesicle gene clusters of the cyanobacteria planktothrix rubescens/agardhii. We then report the utility of these nanoparticles as multiplexed, sensitive, and genetically encoded contrast agents for hyperpolarized xenon chemical exchange saturation transfer (HyperCEST) MRI.
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Ruppert K, Amzajerdian F, Hamedani H, Xin Y, Loza L, Achekzai T, Duncan IF, Profka H, Siddiqui S, Pourfathi M, Cereda MF, Kadlecek S, Rizi RR. Rapid assessment of pulmonary gas transport with hyperpolarized 129Xe MRI using a 3D radial double golden-means acquisition with variable flip angles. Magn Reson Med 2018; 80:2439-2448. [PMID: 29682792 DOI: 10.1002/mrm.27217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/20/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE To demonstrate the feasibility of using a 3D radial double golden-means acquisition with variable flip angles to monitor pulmonary gas transport in a single breath hold with hyperpolarized xenon-129 MRI. METHODS Hyperpolarized xenon-129 MRI scans with interleaved gas-phase and dissolved-phase excitations were performed using a 3D radial double golden-means acquisition in mechanically ventilated rabbits. The flip angle was either held fixed at 15 ° or 5 °, or it was varied linearly in ascending or descending order between 5 ° and 15 ° over a sampling interval of 1000 spokes. Dissolved-phase and gas-phase images were reconstructed at high resolution (32 × 32 × 32 matrix size) using all 1000 spokes, or at low resolution (22 × 22 × 22 matrix size) using 400 spokes at a time in a sliding-window fashion. Based on these sliding-window images, relative change maps were obtained using the highest mean flip angle as the reference, and aggregated pixel-based changes were tracked. RESULTS Although the signal intensities in the dissolve-phase maps were mostly constant in the fixed flip-angle acquisitions, they varied significantly as a function of average flip angle in the variable flip-angle acquisitions. The latter trend reflects the underlying changes in observed dissolve-phase magnetization distribution due to pulmonary gas uptake and transport. CONCLUSION 3D radial double golden-means acquisitions with variable flip angles provide a robust means for rapidly assessing lung function during a single breath hold, thereby constituting a particularly valuable tool for imaging uncooperative or pediatric patient populations.
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Affiliation(s)
- Kai Ruppert
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Faraz Amzajerdian
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Luis Loza
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tahmina Achekzai
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ian F Duncan
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harrilla Profka
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mehrdad Pourfathi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Maurizio F Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rahim R Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
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Ruppert K. Biomedical imaging with hyperpolarized noble gases. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:116701. [PMID: 25360484 DOI: 10.1088/0034-4885/77/11/116701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hyperpolarized noble gases (HNGs), polarized to approximately 50% or higher, have led to major advances in magnetic resonance (MR) imaging of porous structures and air-filled cavities in human subjects, particularly the lung. By boosting the available signal to a level about 100 000 times higher than that at thermal equilibrium, air spaces that would otherwise appear as signal voids in an MR image can be revealed for structural and functional assessments. This review discusses how HNG MR imaging differs from conventional proton MR imaging, how MR pulse sequence design is affected and how the properties of gas imaging can be exploited to obtain hitherto inaccessible information in humans and animals. Current and possible future imaging techniques, and their application in the assessment of normal lung function as well as certain lung diseases, are described.
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Imai H, Kimura A, Akiyama K, Ota C, Okimoto K, Fujiwara H. Development of a fast method for quantitative measurement of hyperpolarized 129Xe dynamics in mouse brain. NMR IN BIOMEDICINE 2012; 25:210-217. [PMID: 21755553 DOI: 10.1002/nbm.1733] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 03/23/2011] [Accepted: 03/24/2011] [Indexed: 05/31/2023]
Abstract
A fast method has been established for the precise measurement and quantification of the dynamics of hyperpolarized (HP) xenon-129 ((129)Xe) in the mouse brain. The key technique is based on repeatedly applying radio frequency (RF) pulses and measuring the decrease of HP (129)Xe magnetization after the brain Xe concentration has reached a steady state due to continuous HP (129)Xe ventilation. The signal decrease of the (129)Xe nuclear magnetic resonance (NMR) signal was well described by a simple theoretical model. The technique made it possible to rapidly evaluate the rate constant α, which is composed of cerebral blood flow (CBF), the partition coefficient of Xe between the tissue and blood (λ(i)), and the longitudinal relaxation time (T(1i)) of HP (129)Xe in the brain tissue, without any effect of depolarization by RF pulses and the dynamics in the lung. The technique enabled the precise determination of α as 0.103 ± 0.018 s(-1) (± SD, n = 5) on healthy mice. To investigate the potential of this method for detecting physiological changes in the brain of a kainic acid (KA) -induced mouse model of epilepsy, an attempt was made to follow the time course of α after KA injection. It was found that the α value changes characteristically with time, reflecting the change in the physiological state of the brain induced by KA injection. By measuring CBF using (1)H MRI and (129)Xe dynamics simultaneously and comparing these results, it was suggested that the reduction of T(1i), in addition to the increase of CBF due to KA-induced epilepsy, are possible causes of the change in (129)Xe dynamics. Thus, the present method would be useful to detect a pathophysiological state in the brain and provide a novel tool for future brain study.
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Affiliation(s)
- Hirohiko Imai
- Department of Medical Physics and Engineering, Area of Medical Technology and Science, Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Imai F, Kashiwagi R, Imai H, Iguchi S, Kimura A, Fujiwara H. Hyperpolarized 129Xe MR imaging with balanced steady-state free precession in spontaneously breathing mouse lungs. Magn Reson Med Sci 2011; 10:33-40. [PMID: 21441726 DOI: 10.2463/mrms.10.33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE We investigated the characteristics of hyperpolarized (HP) (129)Xe magnetic resonance (MR) imaging obtained from balanced steady-state free precession (SSFP) measurement of mouse lungs, especially under spontaneous breathing, and compared the results with those obtained using traditional spoiled gradient echo (SPGR) method, focusing on improved signal-to-noise ratio (SNR) and reduced total acquisition time. METHODS We calculated magnetization response of the HP (129)Xe gas for the balanced SSFP sequence under spontaneous breathing to derive optimal conditions for the imaging experiment. We then placed an anesthetized mouse in the magnet (9.4T) supplied with oxygen gas and a mixture of HP (129)Xe gas supplied from a continuous-flow hyperpolarizing system. We obtained an axial plane image of the lung through balanced SSFP and SPGR sequences, changing the various magnetic resonance (MR) imaging parameters, and measured the SNR of these images. RESULTS We demonstrated the clear dependence of image intensity on flip angle and number of shots. The SNR was higher in balanced SSFP than in SPGR and 2.3-fold higher compared at each maximum. In contrast, total acquisition time in balanced SSFP was shortened to about one-eighth that of SPGR using a one-shot acquisition mode. CONCLUSION In HP (129)Xe MR imaging of the lung of a spontaneously breathing mouse, balanced SSFP sequence with multi-shot and centric order acquisition provides higher SNR in a shorter acquisition time than SPGR.
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Affiliation(s)
- Fumito Imai
- Division of Medical Physics and Engineering, Area of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Osaka University, Suita, Japan.
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