1
|
Jahromi AH, Wang C, Adams SR, Zhu W, Narsinh K, Xu H, Gray DL, Tsien RY, Ahrens ET. Fluorous-Soluble Metal Chelate for Sensitive Fluorine-19 Magnetic Resonance Imaging Nanoemulsion Probes. ACS NANO 2019; 13:143-151. [PMID: 30525446 PMCID: PMC6467752 DOI: 10.1021/acsnano.8b04881] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fluorine-19 MRI is an emerging cellular imaging approach, enabling lucid, quantitative "hot-spot" imaging with no background signal. The utility of 19F-MRI to detect inflammation and cell therapy products in vivo could be expanded by improving the intrinsic sensitivity of the probe by molecular design. We describe a metal chelate based on a salicylidene-tris(aminomethyl)ethane core, with solubility in perfluorocarbon (PFC) oils, and a potent accelerator of the 19F longitudinal relaxation time ( T1). Shortening T1 can increase the 19F image sensitivity per time and decrease the minimum number of detectable cells. We used the condensation between the tripodal ligand tris-1,1,1-(aminomethyl)ethane and salicylaldehyde to form the salicylidene-tris(aminomethyl)ethane chelating agent (SALTAME). We purified four isomers of SALTAME, elucidated structures using X-ray scattering and NMR, and identified a single isomer with high PFC solubility. Mn4+, Fe3+, Co3+, and Ga3+ cations formed stable and separable chelates with SALTAME, but only Fe3+ yielded superior T1 shortening with modest line broadening at 3 and 9.4 T. We mixed Fe3+ chelate with perfluorooctyl bromide (PFOB) to formulate a stable paramagnetic nanoemulsion imaging probe and assessed its biocompatibility in macrophages in vitro using proliferation, cytotoxicity, and phenotypic cell assays. Signal-to-noise modeling of paramagnetic PFOB shows that sensitivity enhancement of nearly 4-fold is feasible at clinical magnetic field strengths using a 19F spin-density-weighted gradient-echo pulse sequence. We demonstrate the utility of this paramagnetic nanoemulsion as an in vivo MRI probe for detecting inflammation macrophages in mice. Overall, these paramagnetic PFC compounds represent a platform for the development of sensitive 19F probes.
Collapse
Affiliation(s)
- Amin Haghighat Jahromi
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
| | - Chao Wang
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
| | - Stephen R. Adams
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, United States
| | - Wenlian Zhu
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
| | - Kazim Narsinh
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Hongyan Xu
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
| | - Danielle L. Gray
- School of Chemical Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
| | - Roger Y. Tsien
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093, United States
| | - Eric T. Ahrens
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
- Corresponding Author: (E. T. Ahrens) Phone: (858) 246-0279.
| |
Collapse
|
2
|
Hegde SS, Zhang Y, Bottomley PA. Acceleration and motion-correction techniques for high-resolution intravascular MRI. Magn Reson Med 2014; 74:452-61. [PMID: 25163750 DOI: 10.1002/mrm.25436] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 08/06/2014] [Accepted: 08/11/2014] [Indexed: 11/07/2022]
Abstract
PURPOSE High-resolution intravascular (IV) MRI is susceptible to degradation from physiological motion and requires high frame-rates for true endoscopy. Traditional cardiac-gating techniques compromise efficiency by reducing the effective scan rate. Here we test whether compressed sensing (CS) reconstruction and ungated motion-compensation using projection shifting, could provide faster motion-suppressed, IVMRI. THEORY AND METHODS CS reconstruction is developed for undersampled Cartesian and radial imaging using a new IVMRI-specific cost function to effectively increase imaging speed. A new motion correction method is presented wherein individual IVMRI projections are shifted based on the IVMRI detector's intrinsic amplitude and phase properties. The methods are tested at 3 Tesla (T) in fruit, human vessel specimens, and a rabbit aorta in vivo. Images are compared using structural-similarity and "spokal variation" indices. RESULTS Although some residual artifacts persisted, CS acceleration and radial motion compensation strategies reduced motion artifact in vitro and in vivo, allowing effective accelerations of up to eight-fold at 200-300 µm resolution. CONCLUSION The 3T IVMRI detectors are well-suited to CS and motion correction strategies based on their intrinsic radially-sparse sensitivity profiles and high signal-to-noise ratios.
Collapse
Affiliation(s)
- Shashank Sathyanarayana Hegde
- Russell H. Morgan Department of Radiology & Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yi Zhang
- Russell H. Morgan Department of Radiology & Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Electrical & Computer Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Paul A Bottomley
- Russell H. Morgan Department of Radiology & Radiological Sciences, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Electrical & Computer Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| |
Collapse
|
3
|
Ahrens ET, Zhong J. In vivo MRI cell tracking using perfluorocarbon probes and fluorine-19 detection. NMR IN BIOMEDICINE 2013; 26:860-71. [PMID: 23606473 PMCID: PMC3893103 DOI: 10.1002/nbm.2948] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 01/29/2013] [Accepted: 02/21/2013] [Indexed: 05/08/2023]
Abstract
This article presents a brief review of preclinical in vivo cell-tracking methods and applications using perfluorocarbon (PFC) probes and fluorine-19 ((19) F) MRI detection. Detection of the (19) F signal offers high cell specificity and quantification ability in spin density-weighted MR images. We discuss the compositions of matter, methods and applications of PFC-based cell tracking using ex vivo and in situ PFC labeling in preclinical studies of inflammation and cellular therapeutics. We also address the potential applicability of (19) F cell tracking to clinical trials.
Collapse
Affiliation(s)
- Eric T Ahrens
- Department of Biological Sciences and Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | | |
Collapse
|
4
|
Abstract
In recent years, there has been an explosive growth of magnetic resonance imaging (MRI) techniques that allow faster scan speed by exploiting temporal or spatiotemporal redundancy of the images. These techniques improve the performance of dynamic imaging significantly across multiple clinical applications, including cardiac functional examinations, perfusion imaging, blood flow assessment, contrast-enhanced angiography, functional MRI, and interventional imaging, among others. The scan acceleration permits higher spatial resolution, increased temporal resolution, shorter scan duration, or a combination of these benefits. Along with the exciting developments is a dizzying proliferation of acronyms and variations of the techniques. The present review attempts to summarize this rapidly growing topic and presents conceptual frameworks to understand these techniques in terms of their underlying mechanics and connections. Techniques from view sharing, keyhole, k-t, to compressed sensing are covered.
Collapse
Affiliation(s)
- Jeffrey Tsao
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA.
| | | |
Collapse
|
5
|
Kuntz J, Gupta R, Schönberg SO, Semmler W, Kachelrieß M, Bartling S. Real-time X-ray-based 4D image guidance of minimally invasive interventions. Eur Radiol 2013; 23:1669-77. [DOI: 10.1007/s00330-012-2761-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 11/24/2012] [Accepted: 11/28/2012] [Indexed: 12/18/2022]
|
6
|
Du H, Lam F. Compressed sensing MR image reconstruction using a motion-compensated reference. Magn Reson Imaging 2012; 30:954-63. [DOI: 10.1016/j.mri.2012.03.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 02/28/2012] [Accepted: 03/08/2012] [Indexed: 11/27/2022]
|
7
|
Macdonald ME, Stafford RB, Yerly J, Andersen LB, McCreary CR, Frayne R. Accelerated passive MR catheter tracking into the carotid artery of canines. Magn Reson Imaging 2012; 31:120-9. [PMID: 22898687 DOI: 10.1016/j.mri.2012.06.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND Using magnetic resonance (MR) imaging for navigating catheters has several advantages when compared with the current "gold standard" modality of X-ray imaging. A significant drawback to interventional MR is inferior temporal and spatial resolutions, as high spatial resolution images cannot be collected and displayed at rates equal to X-ray imaging. In particular, passive MR catheter tracking experiments that use positive contrast mechanisms have poor temporal imaging rates and signal-to-noise ratio. As a result, with passive methods, it is often difficult to reconstruct motion artifact-free tracking images from areas with motion, such as the thoracic cavity. METHODS In this study, several accelerated MR acquisition strategies, including parallel imaging and compressed sensing (CS), were evaluated to determine which method is most effective at improving the frame rate and passive detection of catheters in regions of physiological motion. Device navigation was performed both in vitro, through the aortic arch of an anthropomorphic chest phantom, and in vivo from the femoral artery, up the descending aorta into the supra-aortic branching vessels in canines. RESULTS AND DISCUSSION The different parallel imaging methods produced images of low quality. CS with a two-fold acceleration was found to be the most effective method for generating tracking images, improving the image frame rate to 5.2 Hz, while maintaining a relatively high in-plane resolution. Using CS, motion artifact was decreased and the catheters were visualized with good conspicuity near the heart. CONCLUSIONS The improvement in the imaging frame rate by image acceleration was sufficient to overcome motion artifacts and to better visualize catheters in the thoracic cavity with passive tracking. CS preformed best at tracking. Navigation with passive MR catheter tracking was demonstrated from the femoral artery to the carotid artery in canines.
Collapse
|
8
|
On the utility of spectroscopic imaging as a tool for generating geometrically accurate MR images and parameter maps in the presence of field inhomogeneities and chemical shift effects. Magn Reson Imaging 2012; 31:86-95. [PMID: 22898694 DOI: 10.1016/j.mri.2012.06.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 05/18/2012] [Accepted: 06/21/2012] [Indexed: 11/23/2022]
Abstract
Lack of spatial accuracy is a recognized problem in magnetic resonance imaging (MRI) which severely detracts from its value as a stand-alone modality for applications that put high demands on geometric fidelity, such as radiotherapy treatment planning and stereotactic neurosurgery. In this paper, we illustrate the potential and discuss the limitations of spectroscopic imaging as a tool for generating purely phase-encoded MR images and parameter maps that preserve the geometry of an object and allow localization of object features in world coordinates. Experiments were done on a clinical system with standard facilities for imaging and spectroscopy. Images were acquired with a regular spin echo sequence and a corresponding spectroscopic imaging sequence. In the latter, successive samples of the acquired echo were used for the reconstruction of a series of evenly spaced images in the time and frequency domain. Experiments were done with a spatial linearity phantom and a series of test objects representing a wide range of susceptibility- and chemical-shift-induced off-resonance conditions. In contrast to regular spin echo imaging, spectroscopic imaging was shown to be immune to off-resonance effects, such as those caused by field inhomogeneity, susceptibility, chemical shift, f(0) offset and field drift, and to yield geometrically accurate images and parameter maps that allowed object structures to be localized in world coordinates. From these illustrative examples and a discussion of the limitations of purely phase-encoded imaging techniques, it is concluded that spectroscopic imaging offers a fundamental solution to the geometric deficiencies of MRI which may evolve toward a practical solution when full advantage will be taken of current developments with regard to scan time reduction. This perspective is backed up by a demonstration of the significant scan time reduction that may be achieved by the use of compressed sensing for a simple phantom.
Collapse
|
9
|
Zhong J, Mills PH, Hitchens TK, Ahrens ET. Accelerated fluorine-19 MRI cell tracking using compressed sensing. Magn Reson Med 2012; 69:1683-90. [PMID: 22837054 DOI: 10.1002/mrm.24414] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 06/01/2012] [Accepted: 06/21/2012] [Indexed: 12/25/2022]
Abstract
Cell tracking using perfluorocarbon labels and fluorine-19 (19F) MRI is a noninvasive approach to visualize and quantify cell populations in vivo. In this study, we investigated three-dimensional compressed sensing methods to accelerate 19F MRI data acquisition for cell tracking and evaluate the impact of acceleration on 19F signal quantification. We show that a greater than 8-fold reduction in imaging time was feasible without pronounced image degradation and with minimal impact on the image signal-to-noise ratio and 19F quantification accuracy. In 19F phantom studies, we show that apparent feature topology is maintained with compressed sensing reconstruction, and false positive signals do not appear in areas devoid of fluorine. We apply the three-dimensional compressed sensing 19F MRI methods to quantify the macrophage burden in a localized wounding-inflammation mouse model in vivo; at 8-fold image acceleration, the 19F signal distribution was accurately reproduced, with no loss in signal-to-noise ratio. Our results demonstrate that three-dimensional compressed sensing methods have potential for advancing in vivo 19F cell tracking for a wide range of preclinical and translational applications.
Collapse
Affiliation(s)
- Jia Zhong
- Department of Biological Sciences & the Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | | | | | | |
Collapse
|
10
|
Ajraoui S, Parra-Robles J, Wild JM. Incorporation of prior knowledge in compressed sensing for faster acquisition of hyperpolarized gas images. Magn Reson Med 2012; 69:360-9. [DOI: 10.1002/mrm.24252] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 11/09/2022]
|
11
|
Celik H, Atalar E. Reverse polarized inductive coupling to transmit and receive radiofrequency coil arrays. Magn Reson Med 2011; 67:446-56. [PMID: 21656566 DOI: 10.1002/mrm.23030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 04/25/2011] [Accepted: 05/05/2011] [Indexed: 11/07/2022]
Abstract
In this study, the reverse polarization method is implemented using transmit and receive arrays to improve the visibility of the interventional devices. Linearly polarized signal sources--inductively and receptively coupled radiofrequency coils--are used in the experimental setups to demonstrate the ability of the method to separate these sources from a forward polarized anatomy signal. Two different applications of the reverse polarization method are presented here: (a) catheter tracking and (b) fiducial marker visualization, in both of which transmit and receive arrays are used. The performance of the reverse polarization method was further tested with phantom and volunteer studies, and the results proved the feasibility of this method with transmit and receive arrays.
Collapse
Affiliation(s)
- Haydar Celik
- National Research Center for Magnetic Resonance (UMRAM), Bilkent University, Ankara, Turkey
| | | |
Collapse
|
12
|
Haldar JP, Hernando D, Liang ZP. Compressed-sensing MRI with random encoding. IEEE TRANSACTIONS ON MEDICAL IMAGING 2011; 30:893-903. [PMID: 20937579 PMCID: PMC3271122 DOI: 10.1109/tmi.2010.2085084] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Compressed sensing (CS) has the potential to reduce magnetic resonance (MR) data acquisition time. In order for CS-based imaging schemes to be effective, the signal of interest should be sparse or compressible in a known representation, and the measurement scheme should have good mathematical properties with respect to this representation. While MR images are often compressible, the second requirement is often only weakly satisfied with respect to commonly used Fourier encoding schemes. This paper investigates the use of random encoding for CS-MRI, in an effort to emulate the "universal" encoding schemes suggested by the theoretical CS literature. This random encoding is achieved experimentally with tailored spatially-selective radio-frequency (RF) pulses. Both simulation and experimental studies were conducted to investigate the imaging properties of this new scheme with respect to Fourier schemes. Results indicate that random encoding has the potential to outperform conventional encoding in certain scenarios. However, our study also indicates that random encoding fails to satisfy theoretical sufficient conditions for stable and accurate CS reconstruction in many scenarios of interest. Therefore, there is still no general theoretical performance guarantee for CS-MRI, with or without random encoding, and CS-based methods should be developed and validated carefully in the context of specific applications.
Collapse
Affiliation(s)
- Justin P Haldar
- Department of Electrical and Computer Engineering and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | | | | |
Collapse
|
13
|
Schirra CO, Weiss S, Krueger S, Caulfield D, Pedersen SF, Razavi R, Kozerke S, Schaeffter T. Accelerated 3D catheter visualization from triplanar MR projection images. Magn Reson Med 2010; 64:167-76. [DOI: 10.1002/mrm.22370] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
14
|
Saikus CE, Lederman RJ. Interventional cardiovascular magnetic resonance imaging: a new opportunity for image-guided interventions. JACC Cardiovasc Imaging 2009; 2:1321-31. [PMID: 19909937 PMCID: PMC2843404 DOI: 10.1016/j.jcmg.2009.09.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 01/12/2023]
Abstract
Cardiovascular magnetic resonance (CMR) combines excellent soft-tissue contrast, multiplanar views, and dynamic imaging of cardiac function without ionizing radiation exposure. Interventional cardiovascular magnetic resonance (iCMR) leverages these features to enhance conventional interventional procedures or to enable novel ones. Although still awaiting clinical deployment, this young field has tremendous potential. We survey promising clinical applications for iCMR. Next, we discuss the technologies that allow CMR-guided interventions and, finally, what still needs to be done to bring them to the clinic.
Collapse
Affiliation(s)
- Christina E Saikus
- Translational Medicine Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892-1538, USA
| | | |
Collapse
|