Abstract: A magnetic resonance imaging method and a device for realizing the same for obtaining a magnetic resonance image having corrected phases, wherein the device comprises a construction for generating a static magnetic field, gradient magnetic fields and a radio-frequency magnetic field, irradiating an object to be tested with these magnetic fields and detecting nuclear magnetic resonance signals coming from the object to be tested; a sequence-controlling portion controlling the irradiation of the object to be tested with the gradient magnetic fields and the radio-frequency magnetic field and the detection of the nuclear magnetic resonance signals; and a processing device for reconstructing complex image data on the basis of the nuclear magnetic resonance signals thus detected.

Abstract: Certain wellbore fluid stimulation treatments may be monitored by a system including instrumented manifolds which may be connected between a base fluid source and a blending unit and between the blending unit and fluid injection pumps, respectively for measuring flow rates of the base fluid, the fluid additives and the fluid composition formed by the base fluid and the fluid additives. Instruments are also provided for measuring fluid temperature, pH, viscosity and flow behavior indexes (n', K') and fluid density. Quality control and determination of pressure losses in the wellbore together with modeling of stimulation treatments may be carried out by the continuous monitoring of parameters with the base fluid manifold and the mixed composition manifold.

Abstract: A broadband matching and decoupling network for matching RF coils to an MR system at more than one Larmor frequency using coaxial cable that is equal to 1/4.lambda. at the lower Larmor frequency and an odd multiple of 1/4.lambda. at the higher Larmor frequency.

Abstract: Images of, e.g., a vascular tree, are obtained in a shorter-than-usual time by deliberately undersampling the object, which results in aliasing, and then processing the undersampled data to eliminate the effects of the aliasing.

Abstract: In a magnetic resonance imaging apparatus having a superconducting magnet to form a static magnetic field and capable of producing a magnetic resonance image of a test piece placed in the static magnetic field, a static magnetic field correcting coil corrects the intensity of the static magnetic field, and a power source supplies to the coil a current to form a magnetic field having inverse characteristics with respect to the attenuation pattern of the static magnetic field intensity in the superconducting magnet. Since the static magnetic field correcting coil is supplied with such a current, enhances the stability of the static magnetic field at the time of raising such a magnetic field or immediately after changing the intensity thereof.

Abstract: An improved NMR probe and method are described which substantially improve the resolution of NMR measurements made on powdered or amorphous or otherwise orientationally disordered samples. The apparatus mechanically varies the orientation of the sample such that the time average of two or more sets of spherical harmonic functions are zero.

Abstract: A bridge conductors for the turns of an MRI RF coil may be connected serially within a connector joint area of an inductive coil so as to selectively increase its physical size (e.g., so as to accommodate larger patient volumes to imaged therewithin). Serial capacitance may be included in at least one of the bridging conductors so as to substantially reduce the net inductive impedance of the added bridge conductors such that the standard coil RF tuning and impedance matching circuits may still operate within their normal predetermined adjustable ranges.

Abstract: A guided torsional wave sensor has a cross-section with a strong interaction of torsional wave energy and the surrounding fluid, such that a wave propagates in the sensor with a functional dependence on a single fluid characteristic. In one embodiment, the sensor body is optimized for fluid density. Diamond, polyhedral and curved-sided embodiments are described. In another embodiment, the sensor body responds to fluid viscosity. This embodiment is preferably hollow, and may include threaded, fractal or roughened surface features to enhance viscous coupling. Different systems include further sensors, sensors with portions of differing profile, and special mounting or activation structures.

Abstract: In a magnetic resonance apparatus a gradient coil system and an r.f. coil are combined so as to form a magnetically, electrically and structurally integrated coil system with current conductors in substantially the same cylinder. Thus, a substantial saving is realized as regards the activation energy required for generating gradient fields as well as for generating r.f. fields and notably r.f. stray-fields are also reduced.

Abstract: A probe coil system for a magnetic resonance (MR) apparatus includes a plurality of coil elements, a plurality of shortening capacitor elements, and first and second capacitors. The plurality of shortening capacitor elements are inserted between and in series with the coil elements. The first capacitor is connected in parallel with the coil elements and the shortening capacitor elements. The second capacitors are connected at least in series with the coil elements and the shortening capacitor elements. Each of the shortening capacitor elements includes a plurality of capacitors and a plurality of switches, selectively opened and closed to switch a total capacitance of the plurality of capacitors, allowing selection of one of a plurality of resonance frequencies by adjusting the first and second capacitors within a predetermined range.

Abstract: A method of acquiring data for use in providing magnetic resonance images (MRI) wherein prior to stabilization of the system, data is acquired using phase encoding gradient pulses far removed from zero. Immediately after system stabilization data proximate and equal to the zero value phase encoding gradient pulse is acquired.

Abstract: A system for the quantitative analysis of one or more evolving gases exiting a borehole includes a Venturi ejector for substantially capturing liberated gases in the bell nipple and return line, a rotating disk extractor for substantially extracting gases entrained and dissolved in drilling mud, and a gas analyzer system for analyzing and quantifying the captured and extracted gases. The Venturi ejector preferably is operatively coupled to the return line, and a pipe wiper may be arranged to partially cover the bell nipple. The ejector sucks liberated gases out of the return line and causes a negative pressure to occur at the bell nipple such that air is sucked into the bell nipple rather than exiting the same. The rotating disk extractor has air flowing countercurrent to the mud flow. As the disks rotate, they pick up a thin liquid film of mud which is exposed to the air stream.

Abstract: A physiological phantom standard for NMR imaging and spectroscopy is provided for testing the entire range of image quality parameters over a region comparable to the physiological sample in size, NMR parameters, and RF conductivity. Included in these tests are: signal-to-noise, contrast-to-noise, geometric distortion, slice thickness, slice position, slice profile, slice flatness, T1 and T2 relaxation times, nucleii density, three dimensional spatial resolution, image uniformity, flip-angle accuracy, resonance frequency stabiltity, and positioning system alignment. NMR active materials fills substantially all of the enclosed volume of the phantom to more closely simulate conditions imposed by the anticipated object under test, such as a human subject. The phantom includes a set of coordinate system grids and an associated set of slice parameter grids. The phantom further provides a plurality of chambers which may enclose selectably different NMR active material.

Abstract: A method for providing plural coaxial cable connections, each to a different portion of a single radio-frequency (RF) antenna without requiring the use of isolation means at any RF connection, determines at least a point within the antenna having a desired common potential adjacent to each of the different portions to which one of the coaxial cable connections is to be made; Then forms a separate segment of each different portion which is located substantially at the common potential and is reactively separated from adjacent segments of the associated portion; and connects a shield conductor of an associated coaxial cable to the separate segment, while connecting a center conductor of that same associated coaxial cable to a selected one of the adjacent segments of that different portion.

Abstract: A magnetic resonance spectroscopy system repeatedly performs operations of selectively exciting, using a 90.degree. pulse, first two regions which sandwich a local region therebetween in the direction of one of the X axis and y axis for a slice portion, subsequently erasing transverse magnetization components in the first two regions, selectively exciting, using a 90.degree. pulse, second two regions which sandwich the local region therebetween in the direction of the other of the x axis and y axis, subsequently erasing transverse magnetization components in the second two regions, exciting a region having one local region in the z-axis direction to acquire magnetic resonance data therefor, and exciting a region including another local region in the z-axis direction to acquire magnetic resonance data therefor within a repetition time.

Abstract: Receiver coil for use with a Nuclear Magnetic Resonance Imaging (NMRI) instrument includes a flexible electrical conductor formed from a multiplicity of conductor strips connected in parallel and carried by a flexible insulator. The insulator is configured to be wrapped around an object to be imaged to form the conductor into a coil whose interior is substantially occupied by the object. Air vents may also be provided to improve the ventilation of air through the receiver coil in its wrapped configuration and to reduce any claustrophobic discomfort of a patient.

Abstract: A formation tester is set forth. It incorporates a probe having a surrounding elastomeric seal and snorkel for extension into formations. The probe connects with a sample line into the formation tester. On the sample line, a pressure sensor responds to pressure observed in the sample line and provides a signal for use in control of a motor controller opening and closing relative to hard valve elements and valve seats in a choking action to control flow in the sample line. The sample line then goes to a soft seat valve assembly having a valve element and a seat which delivers controlled sample flow into a chamber for storage within the formation tester.

Abstract: Porosity logs of continuous core are generated using nuclear magnetic resonance (NMR). Core containing naturally-occurring fluids is conveyed between poles of a magnet for NMR analysis. The NMR measures porosity and preferably oil and water saturation and even porosity distribution in the reservoir rock at intervals along the core. The core conveyor, the NMR, and data collection and display are controlled by a processor.

Abstract: A method and apparatus for determining certain fluid flow parameters for naturally fractured media. Specifically provided is a method and apparatus to measure the flow rate, pressure drop, fracture aperture, fluid supply temperature and sample-loading force. A naturally fractured media core sample is obtained for testing and cut into a pair of core blocks having mating fractured forces. The fracture face of the core sample prepared in this manner, yields a more representative surface for flow study, eliminating the problem arising from the fact that most fractures cut across round core samples, resulting in an unnatural, elliptical surface for evaluation. A flow cell assembly is provided to receive the pair of core blocks and secure them during the measurement operation. The flow cell assembly permits adjustment of the fracture aperture to facilitate comprehensive evaluation.

Abstract: A magnetic resonance excitation pulse (50, 150, 250) is applied to excite resonance in selected dipoles in an examination region. A second radio frequency pulse (60, 160, 260) induces a primary echo which is phase encoded by a phase encode gradient (56, 156, 256) with a first phase encode angle. Optionally, an additional phase encode gradient (356) may be applied after the primary echo to remove the first phase encoding. A third radio frequency pulse (70, 170, 270) rotates the magnetization, typically 90.degree., to cause a stimulated echo (72, 172, 272) which is phase encoded in accordance with a second phase encode gradient (78, 178, 278). Optionally, another phase encode gradient pulse (378) may be applied after the stimulated echo to remove the second phase encoding.