James S. Hyde - US grants

Continued support is requested for grant years 09 to 13 for a major program of development of electron spin resonance (ESR) instrumentation and methodology at the National Biomedical ESR Center. The proposal is totally dedicated to pulse or time domain ESR. In past years two unique pulse instruments have been built: a high-speed digital receiver, designated DRP-512, and a receiver with very fast digital phase detection, designated DPD. Our design philosophy has been to focus on Addition: rapid signal acquisition and preprocessing prior to the host computer, with emphasis on the highest possible rate of information flow. The DRP-512 is working well and the DPD has just been completed. Four research topics are addressed here: Three involve the use of the existing receivers in new ways, each with a modest level of development. These three are: (1) Saturation Recovery (SR) electron nuclear double resonance (ENDOR). The effect of induced nuclear resonance on the SR signal is determined. SR ENDOR studies of the structures of copper proteins and of free radicals will be conducted. (2) Multifrequency SR. Capability for S-band as well as X-band SR will be achieved. This will permit measurements of distances in biological systems in the range of 10-100 angstrom units. Separation of Heisenberg exchange and dipole-dipole interactions also will be possible. S-band SR ENDOR experiments are proposed. Multifrequency SR studies of weak Heisenberg exchange will be conducted. (3) Time Domain Spin Label Oximetry. Transient changes in O2 concentration that are caused by a copper vapor laser will be observed using both receivers. Measurements of the permeability of lipid bilayers to molecular oxygen and pulse SR measurements in the context of oxy-radical chemistry and reperfusion injury will be made. A fourth major topic: engineering development of a modernized digital receiver is proposed. Very rapid improvement in host computers, bus concepts, A/D converters and other digital components create copportunities for improved pulse ESR apparatus. The capabilities of the DRP-512 and DPD will be combined in a single "Hardware Development Microcomputer." The proposed instrument will permit a number of new types of experiments. Applications in Time Domain Spin-Label oximetry are particularly emphasized. The National Biomedical ESR Center is the prime facility in the world for development of ESR Instrumentation. ESR is a widely used basic spectroscopic technique that results in more than 2000 scientific papers per year, with about half in the life sciences over a wide variety of subjects.

GM22923 is concerned with development of nitroxide radical "spin-label" electron spin resonance (ESR) methodology. In this competitive renewal for years -14 to -18, focus is on measurements of bimolecular collision rates between (a) spin labels and molecular oxygen (so-called spin-label oximetry), (b) between spin labels and organo-metallic complexes and (c) between spin-labeled biomolecules that contain the 14N isotope and those that contain the 15N isotope. The experiments are based on pulse ESR techniques and computer deconvolution of the resulting multiexponential saturation-recovery signals as developed in the previous funding period. Engineering refinements of the existing high speed signal acquisition equipment are proposed in order to minimize instrumental distortion of transient signals. Essentially all experiments involve synthetic lipid bilayerrs and biological membranes. Most previous spin- label experiments in membranes were concerned with rotational processes, but translational processes studied here through the measurement of bimolecular collision rates are felt to be more biologically relevant. A method has been devised to determine for the first time the oxygen permeability of a membrane. Oxygen transport across the membrane is crucial to cellular respiration. In other studies, rate consants for physical exchange between lipids in two environments in heterogeneous membraneous systems will be measured. Further development of "multifrequency saturation- recovery" equipment will be carried out: namely, construction of a K-band pulse accessory to supplement existing X-band and "under-construction" S- band pulse equipment. Multifrequency saturation-recovery capability will be useful for two purposes: (1) measurement of dipolar non-secular contributtions to spin-label relaxation in fluids, which will improve the quality of the data on bimolecular collisions (this information arises primarily from Heisenberg exchange, but can be confounded by dipolar contributions), and (2) measurement of distances of closest approach between spin labels in membranes and metal ions on the membran surface. A considerable amount of organic synthesis of novel spin labels, organo- metallic compounds and 15 N- substituted spin labels is proposed including synthesis of phospholipids with metal-ion chelation groups attached to the phosphate groups. This is an interdisciplinary program involving physicists, biochemists, biophysicists, chemists, and engineers at the National Biomedical ESR Center.

Feasibility studies have been completed on design and evaluation of a new class of local (or surface) coils for magnetic resonance imaging and 31P spectroscopy at 1.5T. Strategies have been found to obtain localized depth sensitivity using pairs and also twin-pairs of coils (or quads); strategies have been found to provide geometrical isolation of coils when used as receivers from quadrature whole body excitation fields; and strategies have been found to reduce and perhaps eliminate need for adjustments of tuning or matching. High resolution images are shown of the cervical and lumbar spine, of the neck, and of the shoulder obtained with the coils. The coils are loop-gap resonators based on microwave electron spin resonance designs that have been scaled to NMR frequencies. Funds are requested to permit aggressive development optimization, engineering characterization, and clinical evaluation of a variety of coil structures based on our newly discovered principles. Computer simulations of coil performance will be further developed. Coils of lower symmetry (and therefore more difficult to construct) will first be modeled theoretically. The coils will be tested with new (and more powerful) gradient coils yielding improved resolution because of the higher intrinsic signal-to-noise ratio. Local coils will also be evaluated for combined excitation and reception. Proposed clinical studies include in-vivo 31P adult human liver and renal transplants, and proton imaging studies of the orbits, temporomandibular joints, parathyroid glands, laryngeal tumors, spinal disk herniation, and knee and shoulder joints. In other proposed studies, local gradient coils will be inserted into the 1.5T magnet, yielding three times higher gradients for MRI of the limbs. Local transmission and receiving coils will yield sufficiently high signal-to-noise that very high resolution images of the extremities can be obtained. This geometry will be evaluated postoperatively on patients who have had microsurgery of the wrist on patients with carpal tunnel syndrome, and on patients with trauma to the ligaments and tendons of the hand.

Continued support is requested for grant years 09 to 13 for a major program of development of electron spin resonance (ESR) instrumentation and methodology at the National Biomedical ESR Center. The proposal is totally dedicated to pulse or time domain ESR. In past years two unique pulse instruments have been built: a high-speed digital receiver, designated DRP-512, and a receiver with very fast digital phase detection, designated DPD. Our design philosophy has been to focus on Addition: rapid signal acquisition and preprocessing prior to the host computer, with emphasis on the highest possible rate of information flow. The DRP-512 is working well and the DPD has just been completed. Four research topics are addressed here: Three involve the use of the existing receivers in new ways, each with a modest level of development. These three are: (1) Saturation Recovery (SR) electron nuclear double resonance (ENDOR). The effect of induced nuclear resonance on the SR signal is determined. SR ENDOR studies of the structures of copper proteins and of free radicals will be conducted. (2) Multifrequency SR. Capability for S-band as well as X-band SR will be achieved. This will permit measurements of distances in biological systems in the range of 10-100 angstrom units. Separation of Heisenberg exchange and dipole-dipole interactions also will be possible. S-band SR ENDOR experiments are proposed. Multifrequency SR studies of weak Heisenberg exchange will be conducted. (3) Time Domain Spin Label Oximetry. Transient changes in O2 concentration that are caused by a copper vapor laser will be observed using both receivers. Measurements of the permeability of lipid bilayers to molecular oxygen and pulse SR measurements in the context of oxy-radical chemistry and reperfusion injury will be made. A fourth major topic: engineering development of a modernized digital receiver is proposed. Very rapid improvement in host computers, bus concepts, A/D converters and other digital components create copportunities for improved pulse ESR apparatus. The capabilities of the DRP-512 and DPD will be combined in a single "Hardware Development Microcomputer." The proposed instrument will permit a number of new types of experiments. Applications in Time Domain Spin-Label oximetry are particularly emphasized. The National Biomedical ESR Center is the prime facility in the world for development of ESR Instrumentation. ESR is a widely used basic spectroscopic technique that results in more than 2000 scientific papers per year, with about half in the life sciences over a wide variety of subjects.

Funds are requested to support in part the XIIIth International Conference on Magnetic Resonance in Biological Systems to be held in Madison, Wisconsin August 14-19, 1988. The last conference held in this country was at Stanford in 1982. This is the first time that it has been held in the Midwest. This conference series emphasizes research that is characterized by outstanding rigor in the application of magnetic resonance to biological systems. It is felt that this is the premier conference in the world in its field. Both NMR and ESR research, including carefully selected human in-vivo NMR studies will be included. About 400 attendees are expected. The conference will utilize the facilities of the University of Wisconsin at Madison.

Continued support is requested for a narrow and focussed program of development and application of surface and local radiofrequency coils for magnetic resonance imaging at 1.5 and 0.5 T and spectroscopy at 1.5 T. The proposal is addressed (a) to improved coil technology, (b) to development of novel imaging and spectroscopy strategies that depend on the special properties of surface coils, and (c) to clinical studies that make use of the improved technology. Improved coils can be achieved by attention to many small technical details in order to arrive at the highest possible free space Q. This is of particular importance in most coil configurations at 0.5 T and for small coils at 1.5 T. One can also improve image quality by tailoring the coils to the anatomic region of interest. But probably the most significant opportunity for improvement of coil performance is based on use of coil arrays. The idea rests on the basic theorem discovered in the previous funding period that there can be no correlation of noise in simultaneously acquired images of the same object if the mutual inductances between members of the coil array are negligible. A special case of this theorem is the quadrature detection surface coil, which is proposed in numerous variations including 31P spectroscopy. Three developments are proposed here that depend on special properties of surface coils: the spatial variation of vector reception field phase differences between two coils can aid spatial 31P localization and is the underlying property for a new method proposed here for making blood-flow velocity maps. In another development, fat suppressed and water suppressed images of small anatomic parts can be obtained with enhanced quality in 4 cm x 4 cm 256 x 256 images. Clinical imaging studies proposed here in detail are based on very high resolution technological advances recently achieved and uniquely available to us and include patients (a) with primary tumors of the skin, (b) with carpal tunnel syndrome, (c) with prostate carcinoma, (d) with cervical carcinoma, and (e) with lateral epicondylitis (tennis elbow). In future years, as the technology proposed here becomes available, clinical studies will be redirected to improved imaging of deep anatomic regions. A consortium is proposed with Duke University, T. M. Grist, P.I., to continue development and applications of surface coils for 31P spectroscopy. Grist is the P.I.'s former student. Of particular technological thrust is development of doubly tuned 31P quadrature detection surface coils, in some cases inserted into special whole volume coils for uniform presaturation. Applications focus on tissue grafts and possible rejection including kidneys, heart and skin.

Partial funding is requested for the purchase of a Bruker Medspec 3T/60 Magnetic Resonance Imaging/Spectroscopy system to be used as a shared instrumention facility at the Medical College of Wisconsin. This instrument is suitable for animal and also certain human studies (particularly heads). It will be sited for convenient access both to the Animal Care facility and to our hospitals by overhead connectors. The magnet has a 52.5 cm clear bore with gradient and shim coils but without rf coils. Numerous self-built specialized rf coils will be built for a wide variety of animal and patient studies. The proposal emphasizes studies on both animals and humans using both imaging and spectroscopy. The user group has approximately equal weighting between the basic science and clinical faculties of the college. There are presently no small-bore high-field animal scanners in Wisconsin nor are there any human scanners that are fully dedicated to research. This instrument will create research opportunities not only for investigators in the College, but also in Milwaukee and throughout the state. It is argued that animal studies that can be extended to humans using the same instrument at the same field are particularly advantageous. It is further argued that 3T will give significantly improved spectroscopy compared to 1.5T. Modest improvements in image quality are also anticipated particularly in the head and extremities. The total cost of the requested instrument is 1.5 million dollars. The present proposal is in the amoilnt of $400,000. The additional cost has been guaranteed by the Dean of the College (see enclosed letter). The cost of operation of the spectrometer will be supported in the first year by the Department of Radiology (see enclosed letter) and in subsequent years by user charges. Currently, all MRI investigations at the College are carried out at night and weekends using a 1.5T clinical scanner. The circumstances are difficult, the instrument overloaded, and the spectroscopy capability very limited. The proposal demonstrates compliance with the first criterion for evaluation of a shared instrument proposal: that the requested instrument will "enhance the planned research endeavors of the major users by providing an instrument that is unavailable or to which availability is highly limited." The requested instrument also will enhance our ability to train Ph.D. students who are in the Interdisciplinary Biophysics Program. Currently, there are 5 students who primarily use MRI in their research.

DESCRIPTION (adapted from investigator's abstract) This proposal concerns the development of improved magnetic resonance imaging (MRI) techniques for visualization of the anatomic structures of the anterior eye at exceptionally high spatial resolution. The principal investigator and two graduate students, who have already designed and tested surface coils of appropriate radio-frequency (rf) for other parts of the body, e.g., limbs, plan to design and construct a local gradient coil suitable for imaging the eye. The hypothesis to be tested is that a combination of surface rf coils and local gradient coils will allow shorter TE values in the imaging sequence, resulting in better in vivo visualization of the lens and microstructures of the eye. The hypothesis will be tested by studying the time-course of the absorption and elimination of Gadolinium-diethylenetriaminepentacetic acid (Gd-DTPA) in rabbit eyes. The data will be analyzed pixel by pixel, and pharmacokinetic images will be created using a graphic work station. An important innovation is a computer strategy for overcoming the blurring of images resulting from involuntary eye movements.

The Society of Magnetic Resonance in Medicine is an international, non-profit professional association devoted to the promotion of research and education in all applications of magnetic resonance in medicine and biology. Members include clinicians, physicists, engineers, biochemists, and technologists. The SMRM is, at present, the only medical society that combines these multiple disciplines in order to best serve medicine and science. The Society was founded in 1982 and has grown to a membership of more than 2,000. Scientific meetings are held annually, with every third year's meeting located outside the United States. The Eleventh Annual Meeting of the Society of Magnetic Resonance in Medicine will be held in Berlin, Germany, from August 8-14, 1992, jointly with the Ninth Annual Meeting of the European Society of Magnetic Resonance in Medicine and Biology (ESMRMB). An attendance of 3,500 scientists, students and physicians is anticipated. The Society will offer educational stipends for students and postdoctoral trainees for this meeting in the amount of $90,000 derived from corporate donors. Of this amount, $65,000 will be available for students from the U.S. (and Canada). Because of the high costs of accommodations and travel from this country, it is estimated that only 71 awards covering 50% of estimated costs can be made, compared to about 100 such awards to Young Investigators from the U.S. and Canada in 1990 and 1991 when the annual meeting was held in this country. The proposal requests supplemental funds in the amount of $26,500 from NIH to allow 29 additional awards. Magnetic resonance (MR) has emerged as a powerful technique with great clinical potential, and it is drawing researchers from many disciplines. Bringing together the finest researchers and the students of this rapidly evolving field will disseminate knowledge and enhance progress in important areas of medical research that bear on virtually every medical discipline.

The broad long-term objective of CA41464 is to increase the signal-to- noise ratio (SNR) of magnetic resonance imaging (MRI) through development of improved radiofrequency (rf) and gradient coils. In this competitive renewal, this objective is focused on the following subjects: (i) 3 Tesla MRI, recognizing that equipment manufacturers are not meeting the coil needs of investigators who use high field scanners; (ii) functional MRI (fMRI), a field in which the applicant's group has a substantial record of achievement; (iii) rf surface coils in the particular context of local gradient and rf transmit coils, recognizing the special problems that arise in this geometry; (iv) shim coils and susceptibility effects; and (v) consideration not only of the signal but also of the noise, recognizing that the noise in an echo-planar imaging (EPI) time course is physiological in origin. There are two interactive categories of Specific Aims: the first is hardware-based and the second is applications-based. In the first category, it is proposed to design, construct, and evaluate a new local head gradient coil that is optimized for spatial resolution within the 1988 FDA field switching guidelines. Image quality will be further enhanced by incorporating new rf coils and local shim coils. In the second category, a model for fMRI contrast-to- noise ratio (CNR), called the constant CNR (CCNR) model, is proposed and tested. Motor and visual paradigms will be used as a function of spatial resolution, echo time (TE), and repetition time (TR) in single- shot partial k-space gradient recalled EPI pulse sequences. fMRI research is moving forward through the work of many groups in several parallel streams: (i) basic cognitive neuroscience, to understand how the normal brain works at a systems level; (ii) physiology of the microcirculation of the brain using the tools of fMRI; (iii) diagnosis and presurgical planning in a context of neurosurgery, particularly involving cancer and epilepsy; (iv) diagnosis and response to treatment of patients with neurophsychiatric or neurodegenerative disease. The research proposed here is in support of these four streams of fMRI research.

The long-term objective of this Program Project is to create a foundation for the application of functional magnetic resonance imaging (FMRI) to medicine. It is proposed to define the physiological basis of the FMRI response (Project I) and to use FMRI to investigate the cerebral organization of vision (Project II), motor control (Project III), and audition and language (Project IV). Project I will distinguish and quantify contributions of task-induced changes in blood oxygenation and capillary flow to FMRI contrast, using the technology of FMRI physics as well as invasive physiological studies in rats. Project I specifically proposes strategies to distinguish parenchymal FMRI response from FMRI signals arising from changes in flow and oxygenation in collecting veins. The three neuroscience projects (II-IV) each begin by examining the parametric relationships between stimulus and movement variables and FMRI signal change. Project II will compare functional maps of the human and simian visual association cortex. Projects II and III will evaluate parallel hypotheses regarding the retinotopic and somatotopic organization of the visual and motor systems. In later years, all three projects will use complex task activation experiments to assess FMR signal changes in polymodal cortex. Projects II and IV will collaborate in investigating polymodal spatial localization and semantic processing. Projects III and IV will collaborate in defining the brain regions involved in timing operations associated with auditory processing and movement. Project IV will determine the organization of auditory cortical regions specialized for speech perception. These projects will be supported by Core A- Administration and Scanner Operation, Core B-Image Acquisition and Processing, which proposes fundamental advances in FMRI technology and signal processing in addition to providing computer services, and Core C- Subject Interface Systems, which is concerned with delivery of stimuli and monitoring of physiological and movement variables. There are four significant technological aspects of the proposal. 1) Purchase of a powerful computer is proposed that will permit real-time display of FMRI signals. 2) Use of a unique head gradient coil with several significant benefits for FMRI. 3) Application of advanced mathematics and statistical procedures for signal analysis, and 4) comparison of FMRI signals obtained at 0.5, 1.5, and 3 T, giving a unique capability to investigate the field- strength dependence of response. FMRI will have a major impact on the clinical disciplines of psychiatry, neurology, neurosurgery, and neuroradiology, leading to improved patient diagnosis, treatment planning, response to treatment, and monitoring of disease. A multidisciplinary effort linking biophysics, physiology, and neuroscience is proposed in order that the technical, methodological, and neuroscientific principles of FMRI can be comprehensively defined as a basis for clinical applications.

The broad long-term objective of this Project is to obtain a fundamental understanding of the basic biophysical and physiological mechanisms of task induced contrasts in human functional magnetic resonance imaging (fMRI). This understanding can be expected to lead to improved fMRI technology, to contribute to knowledge about local control of cerebral hemodynamics, and to provide a basis for the application of fMRI to the field of neuroscience. Progress towards this objective in the previous funding period is described in 4 papers, 2 PhD dissertations, and 101 abstracts. The hypothesis of this Project is that dynamic blood oxygen level-dependent (BOLD) fMRI contrast is a complex integral of vascular and metabolic component that vary over time and space, and that with sufficient a complex integral of vascular and metabolic components that vary over time and space, and that with sufficient a priori information, measurement of particular aspects of the BOLD signal can provide unique information about the physiological events resulting from task activation. This hypothesis is tested in four specific aims, each of which involves parallel studies in humans and in the rat whisker-barrel cortex, an fMRI model that was developed in the previous funding period: (1) to determine the effects of vascular architecture on the fMRI signal; (2) to correlate the spatial extent of the fMRI signal with neuronal activation; (3) to better characterize fMRI temporal patterns; and (4) to pursue in greater depth the study of underlying physiological fluctuations. The research will be based on several recent breakthroughs including: (1) greatly enhanced fMRI spatial resolution through the use of partial k- space gradient-recalled echo-planar imaging; (2) use of embedded contrast for precise comparison of task-activation response to two independent variables; (3) enhanced understanding of underlying physiological fluctuations in fMRI data sets; and (4) refinements of the 3 T scanner for state-of-the-art sensitivity and stability using local gradient coli technology. The protocols of the new specific aims follow from the work of the previous funding period, but at increased specificity and detail based on the substantial progress that was made. Functional MRI is a truly significant advance towards the goal of understanding brain function, with enormous potential impact on human health. It is essential that it have a firm foundation that is based on rigorous biophysical and physiological studies.

The purpose of this Core is to support he scientific projects by providing and maintaining safe and effective subject interface systems, which collectively include all aspects of the systems, which collectively include all aspects of the systems used to present stimuli, monitor responses and physiologic events, and minimize acoustic noise exposure and subject movement. These systems are essential to all of the scientific projects because fMRI research is predicted on the ability to stimulate the brain and control behavior in a very specific manner. The systems proposed will provide essential new services and capabilities to the scientific groups, or enhance the existing user interface. The new systems will be easier to use and compatible with a wide range of subjects than the systems currently used. Although the efforts associated with the following specific aims will result in systems primarily intended for human subjects, this work will also provide new or enhance systems for use with animal subjects. The first set of specific aims is focused on the development of subject interface systems, and includes developing a standardized system to control and monitor the subject interface systems; improving the capabilities of the scientific groups to deliver high quality visual, auditory, and other sensory stimuli; expanding the types of subject responses that can be monitored; extending the capabilities for monitoring physiologic events; and enhancing the capabilities provided at the Mock scanner facility for training subjects, and acquiring behavioral and psychophysical data in a simulated MRI environment. The second set of specific aims is focused on characterizing the acoustic noise inside a head gradient coil during fMRI and then using this information to attenuate the noise exposure to the subjects. Although the primary responsibility of this Core is the development of new or enhanced subject interface systems, the core also provides the scientific projects with support services that include maintaining the subject interface systems, and training users in both the safety issues associated with the subject interface systems, and the correct handling and operation of these systems.

The Administrative Core of this Program Project is centered in the administrative structure of the Biophysics Research Institute of the Medical College of Wisconsin, which is expanded to meet the additional responsibilities of the Program Project. The organizational philosophy is that of "participative management," because of the interdisciplinary nature of the program. Input from all involved disciplines are necessary in order to make correct decisions. The Specific Aims of the Core fall into two categories: administration, which includes scientific meetings, training, and various administrative services; and scanner operation, which includes assurance of overall performance of the MRI scanners, assurance of health and safety of human subjects, compliance with vertebrate animal protocols, management of the MCW FMRI brain database, and engineering efforts to optimize scanner performance. An important component of the scanner operation category is development of Quality Control procedures, including novel phantoms that are specific for functional magnetic resonance imaging (FMRI). The scientific component of this Core is to evaluate the role of field strength in FMRI with a goal of optimum triage of subjects among the 0.5, 1.5, and 3 T scanners that are available for the Program Project.

The components and instrumentation for the Q-band EPR bridge (as described in the application) were re-specified, ordered, and received. The Q-band oscillator for this bridge was designed and fabricated. Initial tests of this oscillator were performed. The circuitry for the AFC (automatic frequency control)/tune display has been designed. Circuit board layout has been initiated.

structural biology; technology /technique development; spectrometry; biomedical resource; biomedical equipment development; bioengineering /biomedical engineering;

The microwave portion of this station was designed and most components ordered including a high speed A/D converter. The EGSG 500 MHz A/D card is currently being evaluated. [unreadable]

Plans were made for the fabrication of several more Q-band oscillators. The parts and materials, including the "hard to obtain" piezoelectric discs, were specified, ordered, and received. Five Q-band oscillators were fabricated and tuned. The initial power and phase noise results were slightly better than for previous units. Final testing and hardening of the oscillators is in progress. [unreadable]

structural biology; technology /technique development; computers; spectrometry; biomedical resource; biomedical equipment development; bioengineering /biomedical engineering;

technology /technique development; male; female; magnetic resonance imaging; nervous system; human subject; biomedical resource; biomedical equipment development;

Several X-band loop-gap resonators are in the final stages of construction. Coupling structure was redesigned to help eliminate thread contact problems and give improved tunability. [unreadable]

A beta version of the Windows 95 version of our EPR spectrometer data collection software program "Viking" was completed and tested on several spectrometers and with two different A/D cards. Documentation is in preparation for both the hardware and software to allow dissemination of the program.

A prototype X-band bimodal loop-gap resonator was constructed and tested. Computer simulations were made using Hewett Packard HFSS software. The second prototype is being designed and constructed to improve coupling and decrease interference from unwanted modes.

A new detection method for EPR spectroscopy is described that permitssimultaneous acquisition of multiple in- and out-of-phase harmonics of theresponse to magnetic field modulation for both dispersion and absorption (i) conversion of the microwave carrier to an intermediate frequency (IF) carrier; (ii) sub-sampling of the IF carrier by an A/D converter four times in K IF cycles where K is an odd integer greater than one; (iii) dividing the digital words into two streams, odd indexes in one and even in the other, followed by sign inversion of every other word in each stream; (iv) feeding the two streams to a computer for the digital equivalent of phase-sensitive detection (PSD). The system is broadbanded, in thefrequency domain, with narrow banding for improved signal-to-noise ratio occurring only at the PSD step. All gains and phases are internally consistent. The method was demonstrated for a nitroxide spin label. A fundamental improvement is achieved by collecting more information than is possible using a single analog PSD.

Fabrication of several more Q-band oscillators continued. Five Q-band oscillators were fabricated and tuned. The power and phase noise results were slightly better than for pervious units. Final tested and hardening of the oscillators were performed. Three units have been completed. Two were delivered to Brian Hoffman at Northwestern University and another for Wayne Hubbell at UCLA have been completed. Two additional units are being completed.

Several X-band loop-gap resonators are in the final stages of construction. Coupling structure was redesigned to help eliminate thread contact problems and give improved tunability. Several existing resonators X-band and S-band were refurbished.

This proposal is device design driven. It is based on a recent paper by the PI and his colleagues: J. S. Hyde, H. S. Mchaourab, T. Camenisch, J. J. Ratke, R. W. Cox, and W. Froncisz, EPR detection by time-locked sub- sampling, Review of Scientific Instruments 69, 2622-2628, 1998. On the one hand, this paper established feasibility for the concepts, while on the other, a number of engineering issues arose that require additional research and development. The broad long-term goal is to develop a new general purpose electron paramagnetic resonance (EPR) spectrometer based on modem signal acquisition and signal processing methods and also on very high speed personal computers with very large memory capacity. It is expected that all EPR spectrometers will eventually be based on the ideas introduced in this proposal. Features of time-locked sub-sampling (TLSS) detection include (i) increased sensitivity relative to conventional spectrometers by about a factor of 3; (ii) simultaneous collection of all harmonics of the response of the spin system to field modulation, both in- and out-of-phase for both dispersion and absorption, limited only by adjustable parameters; (iii) broadbandedness, making it ideal for detection of spectra from transient species; (iv) totally digital detection and storage of data without initial signal averaging. The three specific aims involve (i) construction of the instrument; (ii) engineering studies of the instrument with additional upgrades throughout the funding period; and (iii) three biomedical applications made possible by TLSS detection. These applications are not only of interest in themselves, but also will be powerful tests of the capabilities of the instrument. They address three broad areas of biomedical EPR research: (i) nitrogen ligation in copper-containing enzymes; (ii) kinetics of peroxynitrite chemistry; and (iii) measurement of fluctuations in protein structures. EPR spectroscopy is a general approach to the study of the structure and dynamics of proteins and macromolecular assemblies. It is the only method that can detect the formation of free radicals in biology unambiguously. It contributes to health-related research at the basic fundamental level.

DESCRIPTION (provided by applicant): This High End Instrumentation Program proposal requests funds for purchase of a whole-body 3 Tesla magnetic resonance imaging (MRI) scanner. The Major User group consists of nine NIH funded investigators, eight working in functional MRI and one in Cancer research. The Minor User group consists of 15 fMRI researchers, each with potential for NIH funding. The Major Users are from seven academic departments. Their funding consists of 2 P01 and 13 R01 awards. Across Major and Minor users, there are 11 additional MRI based grants of various types. The MRI research program at the Medical College of Wisconsin is based on a General Electric 1.5T Signa whole body scanner purchased in 1984 and a 3T Bruker Medspec head-only scanner purchased in 1992. Both are totally dedicated to research and both are approaching obsolescence. A GE Signa 3.OT LX VWi Base System whole body scanner has been selected at a cost of $2,196,584. The balance of the funds required for purchase will be derived from MCW sources, as will the costs of the RF shielding and preparation of the site. At the time that the actual order is placed, scanners from Siemens and Phillips will also be evaluated. The fMRI team at MCW is large and well funded. It has experience in MRI scanner management. An extensive infrastructure for support of the MRI scanners is in place. The theme of the proposal is enhancement of translational research in fMRI. Increasingly, clinical research studies are underway at MCW that are designed to lead to the use of fMRI in diagnosis of disease and monitoring response to treatment. The new scanner will be in a clinical research environment with additional support from the General Clinical Research Center (GCRC) of MCW, which has an imaging core. It will have no clinical fee-for-service usage. The fMRI group at MCW is superbly positioned to provide leadership at a national level in the use of fMRI in medicine.

DESCRIPTION (provided by applicant): This proposal is device-design driven. Two of the aims focus on development of novel sample resonators for electron paramagnetic resonance (EPR) spectroscopy that provides substantially higher signal-to-noise ratios (SNR) than those currently used. EPR resonators are designed to enhance dynamic molecular structure determination studies using nitroxide radical spin labels at physiological temperatures. The third aim focuses on development of a novel bimodal resonator for nuclear magnetic resonance (NMR) signal enhancement by dynamic nuclear polarization (DNP). The goal of Aim 3 is to open up new opportunities in high-resolution NMR. This first competitive renewal proposal is very strongly based on progress in the initial funding period. The methodology utilizes finite-element modeling of electromagnetic fields for resonator design and both electric discharge machining (EDM) and laser milling for fabrication. Aim 1 proposes development of a second generation loop-gap resonator (LGR) at X-band (10 GHz) to replace the one that has been in widespread usage for site-directed spin labeling (SDSL) for over 20 years. The discovery of the Uniform Field (UF) LGR in the previous funding period is the primary technological driver for this project. Another driver is the long-slot iris, which enables direct coupling to a waveguide replacing the previous coaxial-coupler configuration. The goal of this aim is increase of SNR by a factor of 5. Aim 2 proposes to develop a UF TE011 cavity resonator tailored to optimize concentration-sensitivity at Q-band (35 GHz). This is a novel design objective at Q-band. In addition to UF cavity technology, experience in custom fabrication of polytetrafluoroethylene (PTFE) extruded sample cuvettes is a technology driver. Resonators will be tailored for a specific extrusion utilizing as much as 10

DESCRIPTION (provided by applicant): The dominant usage in NIH-funded grants is in the field of site-directed spin-labeling (SDSL) using nitroxide radical spin labels to probe molecular structure. The Technology Research and Development (TR&D) component of this application for continued support of the National Biomedical EPR Center, a P41 Research Resource, focuses on technology enhancement for SDSL applications of EPR. The TR&D component is tightly linked to the Collaborative component, with most collaborations falling in the SDSL classification. Applications involving metal ions are next among NlH-supported grants using EPR, and in this submission, special emphasis is placed in the Service component on making EPR capabilities available to this community. Training and Dissemination components are broadly based and vigorous. We introduced the technology of non-adiabatic rapid sweep (NARS) spectroscopy in the current funding period as a general purpose replacement for phase-sensitive detection (PSD) in EPR spectroscopy. NARS capabilities will be built at L-, X-, Q-, W-, and D-band. Extension to adiabatic rapid sweep (ARS) was demonstrated at W-band during the current funding period, establishing feasibility for Fourier transform EPR using ARS technology with arbitrary waveform generator (AWG) sweep, which is proposed. The intermediate passage range of magnetic field sweep will be used to probe very slow motions. Microwave frequency sweep will be developed at Q-, W-, and D-band. TR&D Project 1 focuses on development of the new technology at L,- X-, and Q-band; Project 3 carries the technology to W- and D-band; and Project 2 focuses on two L-band applications: distance determination at room temperature to 40 A and L-band electron-electron double resonance (ELDOR) for measurement of protein and membrane electrostatic potentials. The M = 0 line of perdeutero 14N spin labels is narrow and very nearly isotropic, making it an ideal probe for these two experiments. New resonators tailored for NARS detection are proposed. The ten collaborations are very tightly linked to the three TR&D projects. The strong support letter for this project from Prof. Wayne L. Hubbell, UCLA, who is also chairman of the External Advisory Committee for the Center, is notable. Collaborations demonstrate widespread interest in the SDSL community. The TR&D theme in this submission is non-adiabatic, adiabatic, and rapid passage technology development across a wide range of microwave frequencies for SDSL research. The NIH RePORTER database reveals 124 R0I research grants that use EPR. We serve the holders of these grants to enhance the nation's biomedical research. Progress in the current funding period includes 220 papers.

DESCRIPTION (provided by applicant): This proposal is technology-development driven. It also contains two pioneering applications of new technology for functional connectivity magnetic resonance imaging (fcMRI), which is also called resting-state fMRI (R-fMRI). Emphasis of this submission focuses on fMRI technology and analysis for rat brain because small- animal fMRI technology appears to be severely underdeveloped. We discovered fcMRI in human brain in 1995 and extended the discovery to rat brain at 9.4 T in 2008. Support is requested for continued development of technology and methodology for enhancement of fcMRI in rat brain. Spatial resolution for fcMRI will be 300 micron cubic or smaller, and it is this high resolution that makes this proposal exciting. We seek to achieve columnar and laminar fcMRI spatial resolution in rat brain cortex. Development of new and innovative radio frequency (RF) surface coils is proposed in Aim 1 that will allow the rat forepaw barrel subfield (FBS) to be imaged at extremely high resolution as described in the detailed studies of Aim 2. These coils will be developed and carefully compared. The best will be used in further studies. The FBS is a group of 23 cortical columns, or barrels, that provide the sensory representation of the forepaw. We have discovered that these columns can be electrically stimulated, one by one, using very small bipolar electrodes placed on the forepaw. Electrodes will be placed at eight locations, which will then be stimulated in pseudorandom manner. Seed voxels at each laminar level are defined for each column by fMRI, and connectivity studies are carried out between those voxels. We carry out fcMRI between, and possibly within, columns both intra- and inter- hemispherically. This is new and highly innovative, and the preliminary data are solid. Furthermore, two multi-coil arrays are proposed in Aim 1 that enable the whole resting-state rat brain connectome to be acquired as described in the detailed studies of Aim 3. It is noted that there appear to be no reports of multi-coil usage in rat brain in the literature, making this coil development highly innovative. Two new and highly innovative pulse sequences developed in this laboratory for human imaging will be translated to rat-brain usage at 9.4 T. Temporal acceleration is obtained by enhanced rate of acquisition of each image slice and by parallel slice acquisition (which uses one of the new sequences) working in concert. In addition, a cluster of relaxation parameters will be obtained for each voxel using the other new sequence. These parameters will allow segmentation by tissue type: only gray matter will contribute to the rat connectome-an approach that is believed to be novel and innovative. The impact of the proposal is twofold. First, it contributes to the foundation of fcMRI, which is a rapidly growing field. This growth is occurring because the entire brain can be probed, which is not possible using task-activation methods. And, second, it strengthens the use of rat models of human disease because it enhances functional imaging of the central nervous system (CNS).

[unreadable] DESCRIPTION (provided by applicant): This is an instrumentation development proposal for improved electron paramagnetic resonance (EPR) spectroscopy for biomedical research. Specifically, the applicants propose to develop saturation recovery (SR) EPR and SR electron-electron double resonance (ELDOR) apparatus at high microwave frequencies that is tailored for experiments using nitroxide radical spin labels and spin probes, in the context of site-directed spin labeling (SDSL). These studies help to determine the dynamics of molecular structure. SR is often used to study bimolecular collisions of oxygen with spin labels. Measurement of oxygen accessibility in SDSL permits identification of structural motifs of proteins. In this proposal, focus not only is on oximetry but also on the use of SR EPR and SR ELDOR to study slow rotational diffusion of proteins. This laboratory pioneered extension of SR instrumentation to high microwave frequencies. The first SR instrument at Q-band (35 GHz) was developed in the previous funding period, and the first at W-band (94 GHz) in the current funding period. It was discovered that the loop-gap resonator (LGR) yields outstanding performance because of high bandwidth and high efficiency in concentrating the microwave field intensity. In Aim 1 of this proposal, extension to D-band (144 GHz) using an LGR is proposed. The features of the relatively immobilized spin-labeled protein no longer overlap at this frequency, which is highly advantageous. The design is based on an innovative combination of microwave frequency translation and low order multiplication. In Aims 2 and 3, SR technology at W-band (94 GHz) will be enhanced. As in Aim 1, these two aims focus on application to proteins undergoing slow rotational diffusion. In Aim 2, the level of microwave power will increase, the pulses will become shorter, and the dead-time will be decreased: all of which will improve SR EPR and SR ELDOR in the study of slow rotational diffusion. The technique of inversion recovery (IR) will be developed, which in comparison with SR will improve the SNR by two times and improve temporal resolution by about ten times. In Aim 3, another way to excite the spin system is introduced: use of adiabatic rapid passage (ADR) by sweep of the microwave frequency from one point in the spectrum to another to excite the spins. The discovery that LGRs are useful at high microwave frequencies because of high bandwidths is central to Aim 3. A state-of-the-art arbitrary waveform generator (AWG) is an enabling technology for frequency swept ADR excitation. Aims 2 and 3 are expected to be complementary, with the methods of Aim 2 being on a shorter timescale and the methods of Aim 3 providing more uniform excitation over well-defined regions of the spectrum. The engineering team is very experienced and is considered to be a national resource. This proposal contributes to the nation's infrastructure for biomedical research. Developed instruments become available to all researchers through the National Biomedical EPR Center, a P41 Research Resource directed by the PI. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): This application is submitted in accordance with PA-02-057, Fogarty International Research Collaboration Award (FIRCA).The research will be done primarily in Poland, at the Jagiellonian University in Krakow in collaboration with Prof. Wojciech Froncisz, PhD, DSc, who is the Foreign Collaborator. It is an extension of NIH grant R01 EB001417, which is the Parent Grant. This proposal is device-design driven. The goal of the proposed work is to improve sensitivity in electron paramagnetic resonance (EPR) spectroscopy of aqueous fluid-phase samples. The proposal is timely because of recent advances in software for finite-element modeling of electromagnetic fields, computers with greatly improved computing speeds, and computer- controlled electric discharge machining (EDM). Computer-aided design will be used for resonators, sample cells and field modulation coils, followed by experimental evaluation. There are three Specific Aims, each of which involves the construction and evaluation in Poland of a sample-containing microwave resonator for EPR spectroscopy: (1) Loop-Gap Resonators (LGR) for Aqueous Samples. An LGR will be developed with ultra-high efficiency. (2) Uniform Field Cavity Resonators for Aqueous Samples. A Q-band uniform field cavity resonator will be developed for use with a novel sample-cell geometry and (3) Aqueous Sample Cell Clusters. A new Multipurpose cavity will be developed for use with layered flat cells. A theme of all three designs is use of EDM graphite, which has recently been proposed by us for EPR resonator construction. The P.I. serves as Director of The National Biomedical EPR Center, P41 EB00198Q, which is a Research Resource. Resonators developed under this FIRCA proposal will enhance the large number of Collaborative and Service Research projects carried out at the Resource. EPR spectroscopy is an important modality in biomedical research. Studies of short-lived radicals detected by spin trapping, of molecular structure using site-directed spin labeling, of biological or model membranes using spin probes, and of cell or tissue preparations are usually carried out in an aqueous environment. Work proposed here will improve the quality of data obtained in these experiments. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): The broad long-term objective of the Parent Grant (EB000215) is to improve the quality of fMRI data including improved contrast-to-noise ratio, higher spatial resolution, increase of information content in the experiment, and improved temporal resolution. The Description of Aim 3 from the Parent Grant is as follows: "Most fMRI studies with rats have used anesthesia, and studies on the awake, mechanically immobilized rat can be criticized as placing the animal under too much stress. Both stress and anesthetics are confounding factors. The goal of this aim is to develop methodology, hardware and software to eliminate the necessity of using anesthetics in fMRI research using rats. Technology will be developed at 3T and extended to 9.4T." Using progress that has been made on this Aim, an fMRI model of nerve transfer in a rat is proposed that will be used to investigate cortical plasticity following surgery. In Aim 1, the fMRI stimulus will be delivered by surgically implanted bipolar electrodes on the right musculocutaneous nerve to allow direct nerve stimulation in an fMRI experiment. Two methods for control of the experiment, both using needle electrodes, will be compared: left forepaw interdigital nerve stimulation and left biceps musculo-cutaneous nerve stimulation. In Aim 2, a nerve transfer experiment is designed with C7 nerve transfer to the right brachial plexus. In this Aim, cortical plasticity over time will be observed directly using fMRI. The controls will be the same as for Aim 1. This NIBIB Research Supplement will provide research experience for a clinical resident in plastic surgery that is based on progress that has occurred on Aim 3 of the Parent Grant. Mentoring in this strongly interdisciplinary proposal will be provided by the PI (fMRI Biophysics); Dr. Hani Matloub, Co-Pi, Microsurgeon; Dr. Ji-Geng Van, Co-Mentor, C7 nerve transfer surgery; and Dr. Safwan Jaradeh, Co-Mentor, clinical electrophysiology. The Clinical Resident, Dr. Younghoon R. Cho, has a well articulated goal of a career in academic medicine. This candidate has both MD and PhD degrees. He will receive training in fMRI small animal research, in electrophysiology, and in nerve transfer microsurgery. The proposed research has significant opportunity to enhance knowledge and could well serve as the basis of a research career in medicine. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Three fMRI CPT codes (for clinical billing and insurance) have been approved and went into effect January 1, 2007. Clinical fMRI will expand rapidly. However, clinical fMRI is often confounded by excessive patient motion. Studies are lost and subjects need to be recalled. Moreover, during the fMRI scan, patients must adequately perform a behavioral task, which can suffer if they become fatigued or fall asleep. Functional MRI studies often take too long. These two problems-patient motion/performance and scan-session length-are the focus of this proposal. Improved methodology is the goal. The three aims address the problems from different perspectives: Aim 1: Pulse sequences and imaging physics for separation of fMRI signals from motion artifacts;Aim 2: Real-time statistics and image analysis for shortening scan duration and improvement of noise immunity;Aim 3: Management of scan-session duration with adaptive acquisition paradigms, multi-parameter mapping, and real-time clinically relevant displays. The aims come together in multifaceted interactive attacks on the two problems. Motion-contaminated data will either be fixed in real time or censored in real time accompanied by additional data acquisition. On a voxel-by-voxel basis, adaptive Kalman filtering will adjust baseline variation caused by slow-motion drift. Higher receiver bandwidth can reduce motion artifacts in several ways. We will explore use of receiver bandwidths as high as 1 MHz, with correspondingly higher gradient strengths. At its essence, this is a study of physiological noise relative to scanner preamplifier noise. As for scan-session length, studies should not extend longer than necessary for statistically significant results, which requires real-time statistical analysis. Randomized multiplexed behavioral paradigms reduce test time. In addition, all of the foregoing techniques will be implemented in near-real time through the use of increased computer power in the MRI scanner suite. In the end, we seek a clinically relevant determination of scan-session success before the patient leaves the scanner, allowing fMRI to be used in a conventional test/retest paradigm. This will significantly improve the success rate of fMRI exams and thereby facilitate the adoption of fMRI as a routine clinical tool. Research will be performed on a GE 3T scanner that was purchased in 2005 using funds made available through the High End Instrumentation Program of the National Center for Research Resources. The work will be carried out by one of the pioneering groups in fMRI. The potential impact of fMRI on brain-related disease is enormous. References are made in the proposal to two specific studies underway at the Medical College of Wisconsin: subjects with mild cognitive impairment that may lead to Alzheimer's disease, and fMRI mapping of visual, motor, and speech function prior to surgical treatment of brain tumors. There are many more.

DESCRIPTION (provided by applicant): This shared instrumentation proposal is for upgrade of an existing research-dedicated General Electric 3T MRI scanner from Version 11B to Version 15. This scanner was installed in 2005 using funds from a high-end instrumentation award from NCRR (S10 RR017215). James S. Hyde, Ph.D., Professor of Biophysics at the Medical College of Wisconsin (MCW) was PI of that proposal and serves again as PI of this proposal. The Department of Biophysics occupies the ground floor of a research tower on the MCW campus, and the scanner was installed in a purpose-built, one-story building attached to the tower at the same level as the departmental floor, providing very convenient access. Funds for construction of this one-story building were provided by MCW, indicating substantial support of imaging research by the institution. The scanner is used exclusively for Neuroimaging. Although there are numerous hospitals and medical facilities immediately adjacent to the MCW campus, there is no clinical fee-for-service usage of this scanner. It is dedicated totally to research. Investigators from numerous departments of MCW, both basic science and clinical, make use of the facility. This upgrade has four major benefits for the user community: (1) greatly improved gradient drivers;(2) state-of- the-art diffusion tensor imaging;(3) upgrade of the eight-channel head coil, eight-channel receiver, and image- formation software to 16 channels for SENSE imaging;and (4) upgrade of the control interface to current levels. With respect to benefit (4), this scanner will be a key aspect of the Clinical Translational Science Institute (CTSI) Imaging Core at MCW and will be employed by investigators across university boundaries at MCW, Marquette University, and the University of Wisconsin-Milwaukee. It is felt to be important that the control interface be up to date for projects intended for early stage translational research. Ten projects are described from nine major funded users. In addition, projects are summarized in tabular form for 14 minor users. The MRI Biophysics research team at MCW has a long history of pioneering technological advances, including very early papers on surface coils (1980s), early human studies at 3T using a 60-cm Bruker scanner that was purchased from a shared instrumentation award (1990s), the first paper to be published on fMRI (1992), the discovery of functional connectivity MRI (fcMRI) (1995), and the earliest report of real-time fMRI. Similarly, the MCW Neuroscience team has long been at the forefront of imaging research on speech and language processing, presurgical mapping in epilepsy, vision and visual attention, motor control and timing, neural systems involved in drug addiction, brain tumor imaging, and early detection of Alzheimer's disease. Projects described in this proposal cover the wide range of imaging science, neuroscience, and translational research that has evolved from these pioneering contributions. The upgrade will enhance the shared use of the centralized MRI resources, enrich ongoing research, promote new research directions, foster a cooperative and interactive research environment, and stimulate multidisciplinary approaches to neuroscience. PUBLIC HEALTH RELEVANCE: Functional magnetic resonance imaging (fMRI) continues to be a rapidly evolving technique that continues to reveal new information about both the healthy and the diseased human brain. This shared instrumentation proposal to upgrade an existing research-dedicated 3 Tesla MRI scanner will have many advantages for the investigators who use the instrument, of which the most important is higher sensitivity using 16 channels of data acquired from the brain simultaneously-so-called SENSE imaging. The applicants are pioneers in the development and application of fMRI.

This core provides input from what is generally agreed to be the leading EPR instrumental development site in the world, the National Biomedical EPR Center at the Medical College of Wisconsin (MCW). The role of this core will be to provide leadership in the development of specific aspects of the technology needed to accomplish the goals ofthe CMCR. These developments will be carried out in collaboration with the projects and with the instrumental Core at Dartmouth, to facilitate the development of the best possible o prototype instruments for EPR dosimetry. The contributions ofthe core at MCW are described in four specific aims. Specific Aim 1 (50% of effort) is the Development of resonators for measurements at X-Band in vivo for nails and teeth;this will be the most extensive project and will focus on exploiting the breakthrough achieved in initial collaborative studies where for the first time, resonators that operate at the very sensitive X-Band frequency were successfully used to make measurements in vivo. This development is at the heart of project 3. During the course of the grant this core will attempt to make analogous resonators that can be used for in vivo tooth dosimetry, which could dramatically improve the already impressive sensitivity of this approach (Project 1). Specific Aim 2 (25% of effort) - Development of instrumentation to support measurements at X-Band, will especially focus on development of specifically designed microwave bridges that will facilitate both Projects 2 &3. These developments will be carried out in collaboration with a longstanding collaborative partner of both Dr. Hyde and Dr. Swartz, Dr. Froncisz of the Jagiellonian University in Krakow (Dr. Froncisz's support will come via a purchase agreement. Specific Aim 3 (20% of effort) - Improvements in resonators and bridges for measurements at L-Band. This core will similarly work with Dartmouth and Krakow in the development of improved L-Band bridges, in support of Project 1. It also will facilitate resonator development in project 1 by use ofthe very sophisticated modeling techniques that are highly developed at MCW, which enable different configurations of resonators to e=be rigorously evaluated so that construction can be focused on designs that are likely to be successful Specific Aim 4 -(5 % of effort) support of multifrequency studies will available an exceptional set of EPR spectrometers that can be of value to all three projects in helping to elucidate the characteristics of potentially overlapping components of EPR spectra.