摘要:
Systems and methods for tomographic reconstruction of an image include systems and methods for producing images from k-space data. A k-space data set of an imaged object is acquired using know k-space data acquisition systems and methods. A portion of the k-space data set is sampled so as to collect some portion of the k-space data. An image is then reconstructed from the collected portion of the k-space data set according to a convex optimization model.
摘要:
Systems and methods for tomographic reconstruction of an image include systems and methods for producing images from k-space data. A k-space data set of an imaged object is acquired using know k-space data acquisition systems and methods. A portion of the k-space data set is sampled so as to collect some portion of the k-space data. An image is then reconstructed from the collected portion of the k-space data set according to a convex optimization model.
摘要:
A readily manufacturable dispenser for roll tissue paper enables use of the paper for general household purposes. First and second parts include longitudinally extending mandrel portions for receiving the roll of tissue that is dispensed through an orifice in the side of the dispenser. The two parts of the dispenser are locked together by an O-ring friction seal between their respective mandrel portions. Knockout tabs in the dispenser end walls enable adaptation to a conventional bathroom fixture.
摘要:
A magnetic resonance imager includes a quadrature coil assembly (20) for transmitting radio frequency signals into and receiving magnetic resonance signal from an examination region. The quadrature coils assembly includes a first coil (22) and a second coil (24). A shunt path (32, 64, 74, 84, 94, 98, 100, 112, 114, 122) provides a current path by shunting at least a portion of one of the coils. A variable impedance (34, 66, 76, 86, 96, 110, 120) adjusts the amount of current flow through the shunt path and the current flow through the bypassed coil portion. More specifically, adjusting the impedance changes the magnetization vector generated by the coil assembly in a transmit mode and adjusts their relative isolation in a receive mode. The quadrature coils are mounted such that they are offset by about, but not quite, 90.degree.. The variable impedance is adjusted until the offset is brought precisely to 90.degree.. In this manner, the quadrature coils are adjusted electronically after assembly to insure the precision of their isolation.
摘要:
Magnets (12) create a main magnetic field along a z-axis through an image region. A localized coil (D) is disposed in the image region at least to receive magnetic resonance signals from nuclei of the subject which have been induced to resonance. The localized coil includes an inner conductor (30), preferably a plate, which defines a current path extending along the z-axis. The inner conductor is mounted closely adjacent and parallel to a surface of the subject. An outer conductor (32), preferably also a plate, is mounted parallel to but further from the subject than the first conductor. A connecting member (34) interconnects a first end of the inner and outer conductors and is disposed perpendicular to the z-axis. A matching circuit (36) including capacitors (50) which define the resonant frequency of the coil are connected adjacent second ends of the inner and outer conductors. Because the nuclei induced to resonance within the z-axis magnetic field generate magnetic resonance components in the x-y plane, an optimal coupling is achieved to reception of the magnetic resonance signals.
摘要:
A resonator coil assembly (32) includes a dielectric sleeve (40) on which a first resonator coil portion (42) and a second resonator coil portion (44), each of copper foil, are adhered. The dielectric sleeve is dimensioned to receive a human torso therein and in one embodiment (FIG. 1) is circular in cross section and in another (FIG. 4) is elliptical in cross section. A pair of adjustable tuning capacitances (64, 66) and a pair of adjustable matching capacitances (68, 70) are interconnected between one end of the each coil portion and a metal bore liner (54). An opposite end of the coil portions are capacitively coupled to each other (FIG. 1) or to the bore liner (FIG. 3). A half wave length cable (72) interconnects the junctions between the first and second tuning and matching capacitances. One of these junctions is connected by a cable (74) with a radio frequency generator (30) and a radio receiver (34).
摘要:
This invention has to do with a stock indicator which includes a strip that will take writing and erasure and which includes printed legends such as "Part No.", "Quantity" and "Date", each associated with blanks to be filled in by pen, pencil or crayon. Such a strip may be designed to provide a counter dial or dials, or may be associated with a separate strip or strips which provide a readily readable dial or dials. Associated with each such dial is a rotary indicator member manually operable step by step in one direction as associated items are withdrawn, and in the opposite direction when items are added or replaced. Indicator devices of this nature may be made at very small cost, and each can be permanently associated with a particular shelf section or bin, or transferred from one stock collection to another if reorganization is required.