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

A cryogenic cooling system (10) for use with a superconductive electric machine (12) includes a first set of components (14) arranged in a first circuit and adapted to force flow of a cryogen in the first circuit (16) to and from a superconductive electric machine (12) and being operable in a cooldown mode for cooling the cryogen and thereby the superconductive electric machine (12) to a normal operating temperature, and a second set of components (18) arranged in a second circuit and adapted to force flow of a cryogen in the second circuit (20) to and from the superconductive electric machine (12) and being operable in a normal mode for maintaining the cryogen and thereby the superconductive electric machine (12) at the normal operating temperature.

Cryogenic cooling system with cooldown and normal modes of operation

An open superconductive magnet useful in magnetic resonance imaging (MRI) applications. The magnet has two spaced apart assemblies, wherein each assembly has a superconductive shielding coil spaced longitudinally outward and apart from a superconductive main coil. A magnetizable pole piece is spaced apart from the coils, has a radially-outer portion at least partially radially overlapping the main coil, and has a longitudinally-inner portion which projects longitudinally inward past the longitudinally outer end of the main coil.

Shielded and open superconductive magnet

A cooling system for a superconductive magnet. A dewar, located outside the magnet, includes a vacuum jacket hermetically connected to the magnet's vacuum enclosure and includes liquid helium located within the vacuum jacket. A thermal busbar is located within and spaced apart from the hermetically connected vacuum jacket and vacuum enclosure. The thermal busbar has a first end located within the vacuum jacket and a second end located within the vacuum enclosure and in thermal contact with the magnet's superconductive coil. A cryocooler coldhead, located outside the vacuum enclosure, has a housing located outside the vacuum jacket and has a cold stage extending from the housing to inside the vacuum jacket to re-liquefy any helium boiled-off in cooling the magnet 10.

Hybrid cooling system for a superconducting magnet

An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies connected by spaced-apart structural posts each having a first end portion attached to the coil form of the first coil assembly and a second end portion attached to the coil form of the second coil assembly. Each toroidal shaped coil form has radially spaced-apart inner and outer generally cylindrical shells and has longitudinally spaced-apart inner and outer annular plates each attached to the inner and outer cylindrical shells. A superconductive coil surrounds, and is attached to, the outer surface of the outer cylindrical shell.

Open MRI magnet having a support structure

Disclosed herein is method for making a wire comprising contacting a first end of a first superconducting wire with a second end of a second superconducting wire, wherein the superconducting wire comprises a superconducting filament having a superconducting composition comprising magnesium diboride; heating the first end of the first superconducting wire with the second end of the second superconducting wire at a point to form a joint, wherein the superconducting filament having the superconducting composition is in continuous electrical contact with any other part of the superconducting filament after the formation of the joint.

Evangelos Trifon Laskaris

Papers

Cryogenic cooling system with cooldown and normal modes of operation

Shielded and open superconductive magnet

Hybrid cooling system for a superconducting magnet

Open MRI magnet having a support structure

Superconducting wire, method of manufacture thereof and the articles derived therefrom