Michael Garwood - US grants

The general objective of this proposal is to develop techniques and pulses which will improve localized magnetic resonance spectroscopy (MRS) and imaging (MRI) studies in vivo, and to apply combined MRS and MRI using these new and previously developed methods to study specific physiologic questions related to intracerebral tumors. A major effort in the proposed study will focus on the development of adiabatic pulses which are insensitive to RF inhomogeneity and which can 1) induce any desired rotation angle, 2) achieve solvent suppression, 3) provide homo-and heteronuclear spectral editing in a single acquisition, despite large variations in RF magnitude. These pulses will enable the use of surface coils as though they generate a highly homogeneous RF field. These methods will be applied in MRS and MRI studies of the metabolism of intracerebral gliomas in rats. A general goal will be to establish whether 1H MRS can detect and define unique metabolic features which distinguish malignant gliomas from normal brain and may ultimately be beneficial in clinical diagnosis. A specific goal will be to gain a better understanding of the regulation of tumor pH. Decreased tumor pH has been shown to sensitize tumors to hyperthermia treatments, as well as to inhibit proliferation of malignant cells. Acute hyperglycemia has been shown to decrease pH in experimental subcutaneous gliomas, but has questionable efficacy in the reduction of intracerebral tumor pH. A specific aim of this study is to induce intracerebral tumor acidosis through the combined effects of hyperglycemia and vasoactive drugs.

DESCRIPTION: (Adapted from investigator's abstract) The general goals of this proposal are to improve the capabilities of in vivo MRS, and to combine these techniques with histopathological and immunohistochemical analyses to provide a better understanding of the pathophysiological alterations observed in Proton MRS of brain tumors. The technique improvements which are proposed are: 1) develop frequency selective adiabatic pulses which uniformly suppress (dephase) magnetization outside tissue regions of interest, despite variations in the radiofrequency field produced by the transmitter coil; and 2) develop adiabatic pulses which will provide uniform excitation in multi slice chemical shift imaging (CSI) implemented with surface coil transmitters. Correlative studies using in vivo MRS and histopathological and immunohistochemical analyses will test the following hypotheses: 1) Brain tumor lactate observed with Proton MRS is compartmentalized into metabolically active and inactive pools. The active pool is produced in viable cells, whereas the inactive lactate is present in necrotic, hemorrhagic, or edematous regions. 2) Glycolytic activity is high in tumor regions densely packed with viable neoplastic cells. During an infusion of C 13 glucose, the C 13 enrichment of lactate in a volume of tumor, as measured with Proton CSI, will be proportional to the fraction of proliferating cells in that volume. 3) The concentrations of choline compounds in brain tumors are indicative of membrane turnover, and therefore, should also correlate with quantitative immunohistochemical measures of cell proliferation. These hypotheses will be tested on intracerebral gliomas induced in rats by three different cell strains: C6, F98, and T24. Concentrations of choline and lactate will be measured with in vivo Proton CSI using high spatial resolution (<1 mm) on a 9.4 Tesla 31 cm horizontal bore magnet. The concentration of metabolically active tumor lactate will be measured following i.v. C 13 glucose infusion using short TE heteronuclear spectral editing. The MRS measurements will be correlated with qualitative and quantitative histology including immunohistochemical measures of proliferation state using monoclonal antibodies against bromodeoxyuridine (BrDU).

One of the originally proposed goals was to establish magnetization preparation for contrast generation using B1 independent adiabatic pulses for a variety of imaging applications to overcome B1 variations encountered at high fields and use surface coils for transmission and reception for imaging, a necessity at the high fields due to difficulties of using "body" coils. Such contrast preparations were initially developed and implemented for cardiac "tagging" using segmented BIR-4 or adiabatic DANTE pulses. Last year, a novel adiabatic contrast preparation in spin-echo imaging has also been introduced, yielding excellent contrast and a reduction in power deposition in human brain imaging at 4T.

We have focused on the development of frequency-swept pulses, known as adiabatic pulses, which compensate for imperfect radiofrequency field (B1) uniformity and resonance offsets. The wide tolerance to B1 inhomogeneity with adiabatic pulses is particularly advantageous in experiments which use a surface transceiver coil to enhance sensitivity. When using a volume coil with uniform B1, adiabatic pulses can still perform better than conventional pulses in many cases. Results in general show that adiabatic pulses are advantageous for many different areas of NMR research ranging from in vivo spectroscopy and imaging to macromolecular structure determination with high resolution NMR spectroscopy. In the past year, we developed new pulses and methods for broadband heteronuclear decoupling with adiabatic pulses were introduced leading to sensitivity enhancement while simultaneously reducing artifacts and permitting automation of complex pulse sequences. A general concatenation procedure to create adiabatic refocusing pulses with bandwidths proportional to the average rather than peak power was developed; these pulses also have symmetric frequency (or slice) profiles and offers unlimited possibilities for concatenating AFP pulses together using any odd number of constituent AFP.

A general concatenation procedure to create adiabatic refocusing pulses with bandwidths proportional to the average rather than peak power was developed; these pulses also have symmetric frequency (or slice) profiles and offers unlimited possibilities for concatenating AFP pulses together using any odd number of constituent AFP.

9907842


Kamil Ugurbil

This grant involves funds for the purchase of a 7 Tesla/90cm bore NMR imaging/spectroscopy instrument for the Center for Magnetic Resonance Research (CMRR) at the University of Minnesota. Only recently has it been possible to develop the necessary instrumentation and methodology, explore the potential and establish the advantages of the higher fields to extract complementary functional and biochemical information. A significant part of that work was realized at the CMRR. The 7T/90 system will enable a major lead in these developments and provide a mechanism by which this unique instrumentation, spin-physics methodology and expertise are available to researchers in the USA and elsewhere.

Unraveling the mysteries of the human brain represents one of the great challenges of modern biology. Recently, developed functional magnetic resonance imaging (fMRI) has provided a unique capability towards meeting this challenge. Further developments to improve sensitivity, spatial specificity and spatial resolution and extend the methodology to temporally resolved true single event related studies require higher neuronal activation and significant increases in the magnitude of the inherently weak signal changes that are used in fMRI. In going to 7 Tesla, these combined gains are expected to catapult this methodology to a level that is significantly beyond what is currently available. Equally important are recent efforts relying on detection of key intracellular bioenergetics and neuronal activity. However, additional gains in sensitivity and spectral resolution available at 7T are needed to make a significant impact on the biological problem.

bioimaging /biomedical imaging; breast neoplasm /cancer diagnosis; diagnosis design /evaluation; diagnosis quality /standard; neoplasm /cancer classification /staging

This project will investigate the use of an emerging technology know as magnetic resonance spectroscopy (MRS) to ascertain the malignancy of breast lesions in vivo. To date, no clinical imaging method provides the needed diagnostic specifity to reliable differentiate benign and malignant breast lesions. The goal of this project is to determine whether a non-invasive biopsy is possible with dynamic MRS measurements of tumor glycolysis.

molecular /cellular imaging; breast neoplasms; breast neoplasm /cancer diagnosis; diagnosis design /evaluation; magnetic field; method development; neoplastic growth; nuclear magnetic resonance spectroscopy; diagnosis quality /standard; magnetic resonance imaging; neoplastic cell; bioimaging /biomedical imaging; clinical research; women's health;

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2-Hydroxy-N,N,N-trimethylethanaminium; CRISP; Cancer of Breast; Choline; Clinical; Computer Retrieval of Information on Scientific Projects Database; Ethanaminium, 2-hydroxy-N,N,N-trimethyl-; Funding; Grant; Hour; Institution; Investigators; Malignant Tumor of the Breast; Malignant neoplasm of breast; NIH; National Institutes of Health; National Institutes of Health (U.S.); Patients; Research; Research Personnel; Research Resources; Researchers; Resources; SYS-TX; Source; Systemic Therapy; United States National Institutes of Health; breast cancer diagnosis; malignant breast neoplasm; response

DESCRIPTION (provided by applicant): Especially since the introduction of functional magnetic resonance imaging (fMRI), a plethora of magnetic resonance (MR) techniques, such as neurochemical spectroscopy, perfusion imaging, imaging of vascular anatomy, diffusion imaging and functional imaging etc., have come to play an indispensable role in neurosciences. Furthermore, many of these methodologies, even at ultrahigh fields such as 7 Tesla, are rapidly moving from the domain of technique development carried out by MR physicist to become an indispensable tool employed routinely by a community of neuroscience researchers without expertise in MR physics. Contemporary use of such MR methodologies in neuroscience research requires immense auxiliary support that includes complex animal surgery, invasive infusions in humans and animal model studies, large scale data and image processing, and complementary non-MR measurements (e.g. electrophysiology, optical imaging, histology etc.). The aim of this proposal is to establish Neuroscience CORE facilities that will augment the existing state-of-the art and unique MR instrumentation resources located in the Center for Magnetic Resonance Research (CMRR) at the University of Minnesota, so as to enable access and utilization of CMRR,A6s resources by a large community of neuroscience researchers, and maximize the impact of modern MR techniques in neuroscience discovery.

[unreadable] DESCRIPTION (provided by applicant): This application seeks funding to upgrade the console of our 4 Tesla human MRI/MRS system located in the CMRR. This 4 Tesla instrument currently runs with a ~9 year old Varian Inova console and currently limits our ability to implement advanced coils (transmit and receive arrays), pulse sequences, and acquisition methods and to achieve optimal data quality in imaging and spectroscopy applications. The Upgrade requested is to replace the existing console with the new Varian Direct Drive console which has uniquely important new capabilities (specifically, 16 receive and 8 transmit channels) and a myriad of significant performance improvements. The multiple receive and transmit channels are the most critical new capabilities sought in this upgrade. This high field MR system is essential to research projects being conducted within our existing P41 Biotechnology Research Resource (RR08079) and the MR CORE of our GCRC (RR00400), as well as to a large number of basic and clinical research projects funded by R01 and other grants. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): This application seeks partial support for a magnetic resonance imaging (MRI) and spectroscopy (MRS) instrument equipped with an ultrahigh magnetic field for in vivo studies of animal models. The proposed animal MRI/MRS instrument will be based on a horizontal 16.4 T magnet having a clear bore diameter of 26 cm, which will be the first of its kind in the nation. It will be located in the Center for Magnetic Resonance Research (CMRR), to take advantage of the high field MR expertise and infrastructure already in place and supported by the NIH. This ultrahigh field MR system will support and enhance research being conducted within a Biotechnology Research Resource grant (P41 RR008079), a Neuroscience Core Center grant (P30 NS057091), and numerous projects funded by R01 and other grants. Among its many new capabilities, this unique 16.4T MR system will provide increased spatial resolution (e.g., for imaging Alzheimer's plaques in mice), increased spatial resolution and specificity in fMRI (e.g., for mapping functional structures in the brain), and increased sensitivity and biochemical information in MRS (e.g., for understanding the coupling between brain function and energy metabolism). [unreadable] PUBLIC HEALTH RELEVANCE: Quantitative imaging is essential to understanding all types of brain diseases. In vivo MRS and MRI has contributed significantly to the current knowledge of normal and diseased brain, but the achievable sensitivity and resolution (spatial and spectral) are limited by the strength of the magnetic field. The proposed MRI/MRS instrument will offer a substantially increased magnetic field (16.4 T) over previous in vivo MR systems, and thus, will yield new structural, functional, and biochemical information in studies of normal brain and disease models. This knowledge, together with the advanced MRI and MRS techniques to be developed, will offer valuable tools for preclinical trials of novel therapeutic agents, and ultimately, for early disease detection and guiding treatments in the clinic. [unreadable] [unreadable] [unreadable]

CRISP; Carcinoma of the Rectum; Clinical Research; Clinical Study; Computer Retrieval of Information on Scientific Projects Database; Detection; Funding; Goals; Grant; Institution; Investigators; MR Spectroscopy; MRS; MRSI; Magnetic Resonance Spectroscopy; NIH; National Institutes of Health; National Institutes of Health (U.S.); Pilot Projects; RF coil; Rectal Cancer; Rectal Carcinoma; Rectum Cancer; Research; Research Personnel; Research Resources; Researchers; Resources; Source; Testing; United States National Institutes of Health; in vivo; pilot study; rectal

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Alzheimer's disease (AD) is poised to become one of the major public health problems facing all industrialized nations in the coming years. No disease modifying treatment has yet been proven to be efficacious and safe in humans. A rate limiting step in discovery of potential disease modifying therapies for humans however is the absence of effective non-invasive methods of testing drugs in animal models of the disease. The focus of this Partnership project is to bridge that gap. In this project, in vivo MRMI as a measure of plaque burden and in vivo MRS as a measure of metabolite changes are employed to measure therapeutic efficacy in drug discovery studies of Alzheimer's amyloid plaque prevention and reduction. The ability to measure therapeutic efficacy is tested by using passive immunization of the AD

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Primarily working on development of SWIFT, including digital receiver, ringdown compensation, SWIFT compatible multichannel coil testing at 4 T, (magnetization prepared) MP-SWIFT, reconstruction and signal processing. "SWIFT (SWeep Imaging with Fourier Transform) is an MRI sequence capable of rapid and quiet MRI imaging. The SWIFT work in Core 3 is focused on continued development and improvement. We have added the capability for magnetization preparation to give improved T1 contrast, T2 contrast, fat suppression, and water suppression. We continue to improve imaging of bone and tendon, dynamic contrast enhancement (DCE) and general short T2 imaging."

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The aim of this project is to develop method based on SWIFT for detection of superparamagnetic iron oxide (SPIO) particle-labeled stem cells in biologically relevant doses in the heart. The preliminary ex- vivo imaging of the heart reveals that SWIFT imaginary images present the off-resonant spins as an enhanced (positive) boundary surrounding the region of SPIO-labeled cells while the on-resonant spins are not visible. SWIFT magnitude images provide myocardium anatomies thus eliminating the need for a separate reference image. Such feature of SWIFT facilitates the detection of stem cells compared to the GRE method.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The ability to target therapeutic or diagnostic proteins to the nervous system is limited by the presence of the blood-brain/nerve barriers. In this project we are testing the hypothesis that modifications of an F(ab2)2 fragment of a monoclonal antibody (IgG4.1) against fibrillar human A[unreadable]42 can be used for the molecular imaging of amyloid plaques in Alzheimer's disease (AD) using high field strength magnetic resonance microimaging (MRMI) (9.4 T). The ability of this contrast agent to image plaques in vivo in AD transgenic mice may lead to early diagnosis of AD in humans and also provide a direct measure of the efficacy of anti-amyloid therapies currently being developed.

? DESCRIPTION (provided by applicant): Functional magnetic resonance imaging (fMRI) continues to play a critical role in understanding the human brain. Yet current fMRI technology is far less than ideal for studying brain function due to the unnatural environment and restricting space of the magnet bore. Furthermore, fMRI cannot be performed on subjects who have metallic implants in their body (e.g., the elderly, soldiers and veterans), or who are impaired by certain physical disabilities as occurs in a variety of neurological and vestibular disorders. Finally, due to its expense and infrastructure requirements, MRI's predominant accessibility to wealthier institutions has resulted in a highly biased subject sampling and a shortage of studies in non-western environments and cultures. The general methodology used to obtain MR images today is essentially the same as that used approximately 4 decades ago. One major drawback of such methodology is that the tolerated magnetic field variation over the brain is limited to a small fraction of the magnet's field, B0. To overcome these limitations, a new MRI methodology has been conceived called STEREO, which stands for steering resonance over the object. By generating images with spatiotemporal-encoding, STEREO allows the B0 field to vary by a large amount, and for the first time, makes it possible to use a smaller, inherently less homogeneous magnet. In this project, the unique capabilities of STEREO will be exploited to demonstrate the feasibility of a portable, remotely supportable, head-only MRI scanner to permit imaging brain function in all populations and environments worldwide. To achieve this goal, this project will develop the STEREO methodology, in combination with new multi-coil gradient technology and new MRI spectrometer technology, to produce human brain images in a highly non-uniform B0. This project will also undertake a feasibility study of a new 1.5 T, high temperature superconducting magnet operating at liquid nitrogen temperature (77 K), to free the requirements for often unavailable liquid helium and/or a stable power supply for cryo-cooling. The overall objective of this grant proposal is to demonstrate the feasibility of critical new methods and technology required for this revolutionary MRI system to become a reality. A multidisciplinary team of leading experts from multiple institutions and industry will meet monthly to report and discuss progress, provide guidance, identify problems and decide corrective courses of action. Based on the experience gained in the process, our new generation MRI system will be specified and designed by the end of this 3-year project. This system will be built and tested with our next round of funding. Making this system available to neuroscientists will open exciting new territories of investigation into the human brain and human behavior, in a wide range of conditions and populations of subjects worldwide.

Magnetic resonance imaging (MRI), by offering the sole means of imaging human brain structure and activity with high spatial resolution, has evolved into an indispensable tool for studying brain function in health and disease. It is uniquely suited to examining the neural basis of higher order behaviors and cognition, as well as neurodegenerative and developmental disorders, for which animal models are of limited applicability. Yet, because of current experimental limitations, there is wide range of subjects and human behaviors that are completely inaccessible by MRI techniques. MRI currently depends on large, expensive, and fixed scanners in which subjects must remain motionless for long periods of time within a confined horizontal space. Thus any behavior involving motion, and especially those involving the upright real-time interaction with objects in natural environments, cannot be studied. Such studies are of enormous scientific interest, for example, in understanding the neuronal basis of motor planning, but also of considerable practical and clinical importance in order to eventually understand and address the motor deficits associated with injury, stroke, or disease which preclude everyday behaviors as important as feeding and reaching. Of particular relevance in this regard is the large population of people with limited ambulatory or vestibular function or difficulty in maintaining posture or smooth movements for which the requirements of remaining motionless in a horizontal space preclude MRI. There is thus an urgent need for a brain imaging technology that is more portable and less restricting than current MRI scanners. One way to address these issues is to decrease the size of the MRI magnet to make a head-only system which does not confine the body, but this approach leads to drastically reduced static field (B0) homogeneity which, with current technologies, precludes high resolution imaging. Now, with the support from BRAIN Initiative grant R24 MH105998, we have addressed the problem by developing new hardware, as well as new acquisition and reconstruction methods, capable of producing high quality brain images despite extreme B0 inhomogeneity. The goal of this U01 project is to build upon these efforts by designing, building, and validating the first-ever human MRI scanner requiring only the head to be inside the magnet bore and having a large window for viewing outside the magnet bore. The small size, weight, and power requirements of this 1.5 Tesla MRI system will enable it to be transported and sited almost anywhere in the world and will be able to bring the magnet to the subject rather than the other way around. To achieve this, a team of leading experts from multiple disciplines and institutions has been assembled. The hardware and software components of this revolutionary MRI system will be constructed and debugged in the first 2 years of the project, the system will be assembled and tested in years 3- 4, and finally in year 5, the MRI system will be piloted in a first of its kind study of motor coordination and planning during natural reaching behaviors. 

PROJECT SUMMARY Contrast in magnetic resonance imaging (MRI) scans of the brain are influenced by complex interactions between water, brain macromolecules and microstructural compenents. The most commonly used MR relaxation-based contrasts change with magnetic field strength, because both T1 and T2 MR relaxation times are field dependent. At higher fields inherent tissue-specific factors, such as bulk magnetic susceptibility due to tissue microstructure and/or biochemical making, affect relaxation thereby influencing MRI contrast. For efficient and adequate use of MR images in neuroscientific research and clinical diagnosis, it is pivotal to understand effects of tissue-related factors on relaxation-based contrasts at clinical (such as 3 Tesla=T) and ultrahigh field (UHF, 7T or above) MRI. The thrust of the proposal is to study the angular dependency of T1 relaxation in human white matter (WM) at 3T and 7T. Our goal is to gain understanding of effects of MR-visible water on the angular dependency of T1 relaxation in WM. Experiments are designed to study the role of the magnetic field strength, axonal diameter and magnetization transfer in the fiber-to-field dependency of MR-visible water and T1 relaxation time. MRI data will be acquired from healthy adult participants at 3T and 7T. The specific aims of the project are as follows: AIM 1: to measure the amplitude of the angular dependency of MR-visible water and T1 relaxation time in WM and study its relationship with WM tracts axonal microstructure, such as axonal diameter. AIM 2: to study the magnetic field dependency of the amplitude of MR-visible water and T1 relaxation in WM. AIM3: to study the effects of magnetization transfer on the amplitude of the angular dependency of MR-visible water and T1 relaxation time in WM at 3T and 7T. The project adds to our long-term pursuit to advance understanding of biophysical underpinnings of MR contrasts in brain images. Our overarching goal is to improve delineation of tissue morphology by MRI for imaging of normal brain and its disorders in modern neuroimaging.

Magnetic resonance imaging (MRI), by offering the sole means of imaging human brain structure and activity with high spatial resolution, has evolved into an indispensable tool for studying brain function in health and disease. It is uniquely suited to examining the neural basis of higher order behaviors and cognition, as well as neurodegenerative and developmental disorders, for which animal models are of limited applicability. Yet, because of current experimental limitations, there is wide range of subjects and human behaviors that are completely inaccessible by MRI techniques. MRI currently depends on large, expensive, and fixed scanners in which subjects must remain motionless for long periods of time within a confined horizontal space. Thus any behavior involving motion, and especially those involving the upright real-time interaction with objects in natural environments, cannot be studied. Such studies are of enormous scientific interest, for example, in understanding the neuronal basis of motor planning, but also of considerable practical and clinical importance in order to eventually understand and address the motor deficits associated with injury, stroke, or disease which preclude everyday behaviors as important as feeding and reaching. Of particular relevance in this regard is the large population of people with limited ambulatory or vestibular function or difficulty in maintaining posture or smooth movements for which the requirements of remaining motionless in a horizontal space preclude MRI. There is thus an urgent need for a brain imaging technology that is more portable and less restricting than current MRI scanners. One way to address these issues is to decrease the size of the MRI magnet to make a head-only system which does not confine the body, but this approach leads to drastically reduced static field (B0) homogeneity which, with current technologies, precludes high resolution imaging. Now, with the support from BRAIN Initiative grant R24 MH105998, we have addressed the problem by developing new hardware, as well as new acquisition and reconstruction methods, capable of producing high quality brain images despite extreme B0 inhomogeneity. The goal of this U01 project is to build upon these efforts by designing, building, and validating the first-ever human MRI scanner requiring only the head to be inside the magnet bore and having a large window for viewing outside the magnet bore. The small size, weight, and power requirements of this 1.5 Tesla MRI system will enable it to be transported and sited almost anywhere in the world and will be able to bring the magnet to the subject rather than the other way around. To achieve this, a team of leading experts from multiple disciplines and institutions has been assembled. The hardware and software components of this revolutionary MRI system will be constructed and debugged in the first 2 years of the project, the system will be assembled and tested in years 3- 4, and finally in year 5, the MRI system will be piloted in a first of its kind study of motor coordination and planning during natural reaching behaviors. 

The broader impact/commercial potential of this I-Corps project is the development of a silent, portable, and affordable Magnetic Resonance Imaging (MRI) system. MRI is a noninvasive medical imaging test that produces detailed images of most internal structures in the human body, including the organs, bone, muscles, and blood vessels. Clinicians receive crucial medical information regarding stroke, tumors, and many other medical conditions from MRI and often regard MRI as the gold standard for imaging. Current MRI instrument, infrastructure, and maintenence costs limit accessibility for approximately 70% of the world's population. The proposed technology seeks to provide a low-cost, portable, and affordable MRI system. An affordable system brings the clinical value of MRI to communities in need and empowers clinicians with crucial life-saving information. The proposed technology may expand the reach and impact of clinical MRI.<br/><br/>This I-Corps project is based on the development of a Magnetic Resonance Imaging (MRI) system using Frequency-modulated Rabi Encoded Echoes (FREE). Currently, MRI systems contains a main magnet (~40% of the cost), B0 gradient coils (~30% of the cost), and B1 radiofrequency coils (10% of the cost). In this MRI system, B0 gradient coils permit encoding and imaging of the body, while B1 radiofrequency coils permit signal creation. FREE is a published B1 encoding approach that allows the removal of B0 gradient coils from a system, cutting the cost of a system by ~30%. In addition, FREE allows the use of imperfect magnets. Imperfect magnets lower the cost for MRI creating additional cost-savings. Also, the proposed technology removes the noisy B0 gradient coils, creating a silent MRI system, reducing the number of hardware components and consequently reducing infrastructure costs. The feasibility of this approach was demonstrated in brain image performed on a conventional system by shutting off B0 gradient coils and encoding with purely B1 radiofrequency coils in one direction. Ongoing research focuses on the complete redesign of a B0 gradientless MRI system to image the body.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.