The United States of America, As Represented by the Secretary, Department of Health and Human Services

The United States of America As Represented by the Department of Health

The United States of America As Represented by the Dept. of Health &

Sankaran Subramanian

James B Mitchell

Murali K Cherukuri

Rolf G Tschudin

Murali Krishna Cherukuri

Nallathamby Devasahayam

Ramachandran Murugesan

Mark S Mirotznik

Bradley Allen Roth

Janusz Koscielniak

John A Cook

Paul G Zablocky

John Bourg

Paul D Smith

Thomas J Pohida

Walter S Friauf

Angelo Russo

Frank S Harrington

Shingo Matsumoto

Mobae Afeworki

An echo-based single point imaging (ESPI) system () providing high-resolution oxygen images of a sample is disclosed. The ESPI system () employs spin echo detection of the resonance from a spin probe and concurrent Single Point Imaging (SPI) for spatial encoding of the oxygen concentration within the sample. Images are derived by comparing spin echo intensities of two images reconstructed at two time points selected at identical time intervals on either side of a refocusing pulse, eliminating artifacts associated with sample magnetic susceptibility and field inhomogeneity effects.

Quantitative oxygen imaging systems and methods using echo-based single point imaging

An electron paramagnetic resonance imaging system that includes means for continuously irradiating a sample with RF irradiation; means for imposing on the sample a sinusoidally varying magnetic field along with rotating gradients for spatial encoding; means for directly detecting signal data from the sample, without using field modulation, while irradiating the sample with RF radiation continuously, the means for directly detecting having means for sweeping the sinusoidally varying magnetic field; and means for processing the signal data, using means including a digital signal processor.

Fast electron paramagnetic resonance imaging (EPRI) using CW EPR spectrometer with sinusoidal rapid-scan and digital signal processing

An electron paramagnetic resonance imaging system that includes means for continuously irradiating a sample with RF irradiation; means for imposing on the sample a sinusoidally varying magnetic field along with rotating gradients for spatial encoding; means for directly detecting signal data from the sample, without using field modulation, while irradiating the sample with RF radiation continuously, the means for directly detecting having means for sweeping the sinusoidally varying magnetic field; and means for transmitting, receiving and processing the signal data, using means including a digital signal processor.

Fast electron paramagnetic resonance imaging (EPRI) in the CW EPR mode using rapid-scan in the presence of rotating gradients and direct detection with transmit/receive and data processing in a digital signal processing platform

A radiofrequency (RF) coil design, suitable for detecting time domain electron paramagnetic resonance (EPR) responses from spin probes after pulsed excitation using radiofrequency irradiation (60-400 MHz), is configured in an array of numerous surface coils of appropriate diameters connected in a parallel or axial configuration with appropriate spacing between individual surface coils to form a volume type resonator.

Resonant structure for spatial and spectral-spatial imaging of free radical spin probes using radiofrequency time domain electron paramagnetic resonance spectroscopy

A system for performing pulsed RF FT EPR spectroscopy and imaging includes an ultra-fast excitation subsystem and an ultra-fast data acquisition subsystem. Additionally, method for measuring and imaging in vivo oxygen and free radicals or for performing RF FT EPR spectroscopy utilizes short RF excitations pulses and ultra-fast sampling, digitizing, and summing steps.

In vivo imaging and oxymetry by pulsed radiofrequency paramagnetic

A gated RF preamplifier used in system for performing pulsed RF FT EPR spectroscopy and imaging or MRI. The RF preamplifier does not overload during a transmit cycle so that recovery is very fast to provide for ultra-fast data acquisition in an ultra-fast excitation subsystem. The preamplifier includes multiple low-gain amplification stages with high-speed RF gates inserted between stages that are switched off to prevent each stage from overloading during the transmit cycle.

Gated RF preamplifier for use in pulsed radiofrequency electron

System and method for performing in vivo imaging and oxymetry and FT

An EPR imager and spectrometer includes pulse generating system for generating broadband pulses having an RF carrier frequency that is not highly absorbed by biological samples. The pulse generating system includes up and down chirp convertors for frequency modulating a carrier frequency pulse and compressing the frequency modulated pulse to form a broadband excitation pulse of high energy. Such a machine could form the basis of a clinical imaging device capable of high sensitivity to free radical species in human patients.

Pulsed low frequency EPR spectrometer and imager

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Rockville, MD, United States of America

Sankaran Subramanian