Other

The University of Chicago

Harvard College

Howard J Halpern

Boris Epel

Yu Zou

Maryellen L Giger

Lifeng Yu

Xiaochuan Pan

Chien-min Kao

Emil Sidky

Dan Xia

Charles A Pelizzari

Martin King

Seungryong Cho

Beverly A Teicher

Subramanian V Sundramoorthy

An apparatus and method for improved S/N measurements useful for electron paramagnetic resonance imaging in situ and in vivo, using high-isolation transmit/receive surface coils and temporally spaced pulses of RF energy (e.g., in some embodiments, a RF pi pulse) having an amplitude sufficient to rotate the magnetization by 180 degrees followed after varied delays, by a second RF pulse having an amplitude half that of the initial pulse to rotate the magnetization by, e.g., 90 degrees (a pi/2 pulse), to the plane orthogonal to the static field where it evolves for a short time. Then a third RF pi pulse sufficient to rotate the magnetization by, e.g., 180 degrees, forms an echo (in some embodiments, the second and third pulses are from the same signal as the first pulse but are phase shifted by 0, 90, 180, or 270 degrees to reduce signal artifact), to image human body.

Stimulated-echo imaging for EPRI

T-sensitive inversion-recovery imaging for EPROI

Method and apparatus for EPROI using T1e spin-lattice relaxation response

The present invention provides an apparatus and a corresponding method useful for electron paramagnetic resonance imaging, in situ and in vivo, using high-isolation transmit/receive (TX/RX) coils, which, in some embodiments, provide microenvironmental images that are representative of particular internal structures in the human body and spatially resolved images of tissue/cell protein signals responding to conditions (such as hypoxia) that show the temporal sequence of certain biological processes, and, in some embodiments, that distinguish malignant tissue from healthy tissue. In some embodiments, the TX/RX coils are in a surface, volume or surface-volume configuration. In some embodiments, the transmit coils are oriented to generate an RF magnetic field in directions substantially orthogonal to a static gradient field, and the receive coils are oriented to sense RF EPR signal in directions substantially orthogonal to the transmitted field and to the static field, to minimize coupling of the transmitted signal to the receive coils.

High-isolation transmit/receive surface coils for EPRI

Method and high-isolation transmit/receive surface coils for EPRI

Techniques provide for passive Q switching in a bimodal resonator environment, where magnetic resonators are coupled for power transfer. A passive Q switch is responsive to a driving power from one magnetic resonator coupled to another magnetic resonator. After the driving power reaches a threshold, the passive Q switch shunts the receiving magnetic resonator, at least partially, to reduce the Q of that second resonator, which allows faster detection operation of the second resonator in some applications. The technique allows for fast Q switching in a bimodal resonator system, especially one having resonators having magnetic fields that are orthogonal to one another.

Method and apparatus for resonator signal production and measurement

[object Object]

A method and apparatus for reconstruction of a region of interest for an object is provided. The reconstruction of the object may be based on chords which may fill a part, all, or more than all of the region of interest. Using chords for reconstruction may allow for reducing data acquired and/or processing for reconstructing a substantially exact image of the ROI. Moreover, various methodologies may be used in reconstructing the image, such as backprojection-filtration, and modified filtration backprojection.

Imaging system

High-isolation transmit/receive surface coils and method for EPRI

A method and apparatus for reconstruction of a region of interest (ROI) for an object using an imaging system is provided. The imaging system may substantially exactly reconstruct the ROI with a straight line trajectory. In the straight line trajectory, the ROI is not bounded or encircled by the actual trajectory of the source (e.g., no chords that are composed from two points on the source trajectory intersect or fill the ROI to be imaged). However, the ROI may be substantially reconstructed by using 'virtual' chords to reconstruct the ROI. The virtual chords are such that no point on the trajectory is included in the virtual chord (such as one that is parallel to the straight line trajectory). These virtual chords may intersect and fill the ROI, thus enabling substantially exact reconstruction. Further, in reconstructing the image, the straight line trajectory may be assumed to be infinite in length.

Imaging system performing substantially exact reconstruction and using non-traditional trajectories

Selective isotopic-labeling of spin label compounds, used in electron spin resonance spectroscopy to detect, measure and monitor the presence of paramagnetic species, increases the sensitivity of the electron spin resonance technique in assays for paramagnetic species, such as the determination of oxygen tension in solution or in a biological sample, like a living organism. Spin label compounds, such as nitroxides, like 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrroline-1-yloxyl (CTPO), are selectively, but not completely, isotopically-labeled, such as partially deuterated, to increase the sensitivity and reliability of assays employing electron spin resonance spectroscopic measurements.

Selective isotopic labeling of spin labels for electron spin resonance

Magnetic resonance images of the distribution of a substance within a sample are obtained by splaying a pair of magnetic field generating coils relative to each other to generate a magnetic field gradient along an axis of the sample. In other aspects, electron spin resonance data is derived from animal tissue, or images are derived from a sample that includes dissipative material, using a radio frequency signal of sufficiently low frequency.

Magnetic resonance analysis of substances in samples that include

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Chicago, IL, United States of America

Howard J Halpern