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

More than 95 percent of infants who have neonatal stroke survive to adulthood, and many have residual motor or cognitive disabilities. This article makes the point that recognition of at-risk newborns by means of advanced methods of neuroimaging, combined with a plan for rational intervention, may result in the prevention or the reduction in the incidence of lifelong disabilities such as cerebral palsy, epilepsy, and behavioral and learning disorders.

https://www.nejm.org/doi/pdf/10.1056/NEJMra041996?articleTools=true

Neonatal brain injury.

A closed-loop control system is disclosed for use with an electrosurgical generator that generates electrosurgical energy. The closed loop control system includes a user interface for allowing a user to select at least one pre-surgical parameter, such as the type of surgical instrument operatively connected to the generator, the type of tissue and the desired surgical effect. A sensor module is also included for continually sensing at least one of electrical and physical properties proximate a surgical site and generating at least one signal relating thereto. The system also includes a control module for continually receiving the at least one selected pre-surgical parameter from the user interface and each of the signals from the sensor module, and processing each of the signals in accordance with the at least one pre-surgical parameter using at least one of a microprocessor, computer algorithm and a mapping. The control module generates at least one corresponding control signal relating to each signal from the sensor module, and relays the control signal to the electrosurgical generator for controlling the same. A method is also disclosed for performing an electrosurgical procedure at a surgical site on a patient. The method includes the steps of: applying at least one electrical pulse to the surgical site; continually sensing electrical and physical properties proximate the surgical site; and varying pulse parameters of individual pulses of the at least one pulse in accordance with the continually-sensed properties.

Method and system for controlling output of RF medical generator

A method for making an intravascular stent by applying to the body of a stent a solution which includes a solvent, a polymer dissolved in the solvent and a therapeutic substance dispersed in the solvent and then evaporating the solvent. The inclusion of a polymer in intimate contact with a drug on the stent allows the drug to be retained on the stent during expansion of the stent and also controls the administration of drug following implantation. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and the ratio of drug to polymer in the solution. By this method, drugs such as dexamethasone can be applied to a stent, retained on a stent during expansion of the stent and elute at a controlled rate.

Intravascular stent and method

An electrosurgical system is disclosed. The electrosurgical system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The electrosurgical generator includes impedance sensing circuitry which measures impedance of tissue, a microprocessor configured to determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid, and an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue.

Vessel sealing system

A magnetic resonance surgery system facilitates performance of surgery with a focussed ultrasound transducer that selectively destroys tissue in a region within a subject. The focussed ultrasound transducer dissipates ultrasonic energy at a focal point within the region of tissue to be destroyed. A number of hydraulic positioners position the focal point under the control of a surgeon. A magnetic resonance imaging system employing a temperature sensitive pulse sequence creates an image of the tissue and the region being heated to allow the surgeon to adjust the position of the ultrasonic transducer so as to direct ultrasonic energy to the appropriate location.

Magnetic resonance guided focussed ultrasound surgery

A positioner for a magnetic resonance (MR) surgery system which positions a focal point of an ultrasound transducer to selectively destroys tissue in a region within a patient. The positioning means moves an ultrasound transducer under the control of an operator. Mechanical threaded shafts and slides act as screw drives causing several connected slides to move the ultrasound transducer in three dimensions. Expanding shafts are connected between a fixed point on a housing and the actuating point of the threaded shafts. Two of the expanding shafts employ universal joints allowing the shafts to rotate as they follow the slides. The third expanding shaft need only expand but the relative angle between its attachment points does not change, thereby eliminating the need for universal joints. An MR imaging system employing a temperature sensitive pulse sequence, creates an image of the tissue and the region being heated to allow the operator to adjust the position of the ultrasonic transducer so as to direct ultrasonic energy to the appropriate location.

Mechanical positioner for magnetic resonance guided ultrasound therapy

Purpose

To determine whether the promise of high-density many-coil MRI receiver arrays for enabling highly accelerated parallel imaging can be realized in practice.



Materials and Methods

A 128-channel body receiver-coil array and custom MRI system were developed. The array comprises two clamshells containing 64 coils each, with the posterior array built to maximize signal-to-noise ratio (SNR) and the anterior array design incorporating considerations of weight and flexibility as well. Phantom imaging and human body imaging were performed using a variety of reduction factors and 2D and 3D pulse sequences.



Results

The ratio of SNR relative to a 32-element array of similar footprint was 1.03 in the center of an elliptical loading phantom and 1.7 on average in the outer regions. Maximum g-factors dropped from 5.5 (for 32 channels) to 2.0 (for 128 channels) for 4 × 4 acceleration and from 25 to 3.3 for 5 × 5 acceleration. Residual aliasing artifacts for a right/left (R/L) reduction factor of 8 in human body imaging were significantly reduced relative to the 32-channel array.



Conclusion

MRI with a large number of receiver channels enables significantly higher acceleration factors for parallel imaging and improved SNR, provided losses from the coils and electronics are kept negligible. J. Magn. Reson. Imaging 2008;28:1219–1225. © 2008 Wiley-Liss, Inc.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/jmri.21463

128‐channel body MRI with a flexible high‐density receiver‐coil array

A novel breast localization and biopsy system employs a chest support for holding the patient in a slightly rotated (20°-30°) prone position allowing the breast tissue hang downward and fit through an opening in the chest support, while holding the other breast against the subject away from the imaging region. A pair of support plates compress the breast tissue. At least one of the support plates has a grid with reference markers for localization and windows allowing a physician access to the breast tissue. A thick biopsy plate with a plurality of holes at marked positions fits into one of the grid openings and guides an interventional device, such a biopsy needle, into a desired location in a lesion. In an alternative embodiment, both breasts fit through the chest support. There are two stabilization plate assemblies, one for each breast and two medical imaging sources. Each source points from the lateral to medial support plate to accomplish imaging of both breasts simultaneously.

Kenneth William Rohling

Papers

Magnetic resonance guided focussed ultrasound surgery

Mechanical positioner for magnetic resonance guided ultrasound therapy

128‐channel body MRI with a flexible high‐density receiver‐coil array

Image guided breast lesion localization device

Magnetic resonance guided ultrasound therapy system with inclined track to move transducers in a small vertical space