By using a multiple receiving coil composed of receiving coils, an imaging portion of a subject is subjected to a first pulse sequence to create n sensitivity images (701 to 703) fewer than the examination images. When these sensitivity images are created, an NMR signal is measured for only the low-frequency region of the k space. A second pulse sequence from which a phase encode step is removed is conducted to create m (m>n) examination images (704, 705) of the subject by using the receiving coils. When sensitivity distributions (707, 708) of the receiving coils are determined for the sensitivity images (701 to 703), and if there are no sensitivity distributions corresponding to the slice positions of the examination images (704, 705), they are determined by slice interpolation using the sensitivity distributions (701 to 703), and the aliasing artifacts of the examination images (704, 705) are removed by matrix operation by using the sensitivity distributions (707, 708).

Magnetic resonance imaging device

A surgical instrument including a switching mechanism which allows a surgeon to selectively advance or retract a staple driver and/or cutting member within a staple cartridge. In various embodiments, the surgical instrument can include a handle, a trigger operatively coupled to the handle, a firing drive, and an end effector. The firing drive can include a first ratchet assembly configured to advance a cutting member in the end effector and a second ratchet assembly configured to retract the cutting member. The trigger can include first and second pawls pivotably mounted thereon which are configured to be selectively engaged with the first and second ratchet assemblies, respectively. In at least one embodiment, the trigger can be configured to slide between a first position in which the first pawl is engaged with the first ratchet assembly and a second position in which the second pawl is engaged with the second ratchet assembly.

Surgical instrument having a directional switching mechanism

Magnetic resonance imaging apparatus

PURPOSE: To develop a superconducting magnetic resonance (MR) imager that provides direct access to the patient and permits interactive MR-guided interventional procedures. MATERIALS AND METHODS: A 0.5-T superconducting magnet that allows a region of vertical access to the patient was designed and constructed. This magnet was integrated with newly designed shielded gradient coils, flexible surface coils, and nonmagnetic displays and with position-monitoring probes and device-tracking instrumentation. RESULTS: The magnet homogeneity was 12.3 ppm, and the gradient field was linear to within 1% over an imaging region 30 cm in diameter. The signal-to-noise ratio was 10% higher than in a comparable 0.5-T superconducting imager. Images were obtained in several anatomic regions with use of routine pulse sequences. Interactive image plane selection and near real-time imaging, with use of fast gradient-recalled echo sequences, were demonstrated at a rate of one image every 1.5 seconds. CONCLUSION: MR-guided interv...

Superconducting open-configuration MR imaging system for image-guided therapy.

Magnetic resonance information acquired by a movable magnetic resonance instrument is used to monitor hyperthermia treatments such as tissue ablation. The instrument may include both the magnetic resonance equipment and an energy applicator such as a high intensity focused ultrasound unit. The treatment can be conducted under automatic control after the operator marks a treatment volume on an image of the subject, such as a magnetic resonance image acquired using the movable magnetic resonance instrument. The automatic treatment can be based on interpolation of tissue response curves at plural test points near the treatment volume. The system can also provide automatic supervisory control during manual operation, to prevent application of heat to sensitive anatomical structures.

MRI-guided therapeutic unit and methods

Cryogenic liquid coolant is transferred from a stationary liquefier through a bayonet to a conduit rotating with the rotor of a superconducting generator, using a cryogenic fluid transfer joint attached to the collector end of the rotor. A relative-motion gap about the bayonet has its inner and outer diameters reduced in size near the outlet end of the bayonet. The gap thus stepped downward in size extends into a core of boil-off coolant within the rotating conduit, preventing liquid coolant centrifugally forced against the inside of the conduit from entering the gap, and allowing only boil-off coolant to enter.

Method of supplying cryogenic fluid through a transfer joint employing a stepped bayonet relative-motion gap

A system to provide mechanical stabilization to high temperature BSCCO-2223 superconducting tape by laminating 0.081 mm thick, spring hard, copper foil to both sides with lead-tin eutectic solder has been successfully optimized. This system has been applied as a method to create a strong, windable composite with a minimum of critical current (I/sub c/) degradation. The "as received" conductor is evaluated for physical consistency of width and thickness. Electrical degradation in the strengthened tape as a result of lamination was found to average 24 percent. This was less than the degradation that would have occurred in an unstrengthened tape during subsequent insulation and coil winding processes. The copper can double the ultimate tensile strength of the pure silver tapes. Additionally, pure silver and dispersion strengthened silver matrix tapes are laminated with 0.025 mm thick copper and 304 stainless steel foil to investigate minimization of the cross sectional area of the strengthening component. The stainless steel can increase the UTS of the pure silver tapes sixfold. Mechanical properties and critical currents of these tapes are also reported both before and after strengthening. The I/sub c/ is also measured as a function of strain on the laminated tapes.

/pdf/mechanical-stabilization-of-bscco-2223-superconducting-tapes-25bsnfao7w.pdf

Mechanical stabilization of BSCCO-2223 superconducting tapes

Supporting tie configuration for cryostat for cold shipment of NMR magnet

A magnetic resonance superconductor magnet is provided comprising a cylindrical coil form having a plural­ity of circumferential grooves. Superconductor wire is wrapped under tension in each of the circumferential grooves. The superconductor wire in each groove forms a main magnet coil. The start and finish ends of the over­wrapped wire is electrically shorted.

Superconducting magnetic resonance magnet and method of making the same

An unimpregnated winding for use in a cryostat of a superconducting magnet is provided comprising a form including a shell having the shape of two truncated cones attached to one another at their respective bases. Superconducting wire is wrapped around the form under tension so that during superconducting magnet operation, the form remains under compression.

Evangelos Trifon Laskaris

Papers

Method of supplying cryogenic fluid through a transfer joint employing a stepped bayonet relative-motion gap

Mechanical stabilization of BSCCO-2223 superconducting tapes

Supporting tie configuration for cryostat for cold shipment of NMR magnet

Superconducting magnetic resonance magnet and method of making the same

Conical, unimpregnated winding for MR magnets