摘要:
In a method to determine a background phase in phase values of a phase image data set that is acquired from an examination subject, wherein the background phase is determined in a partial region of the phase image data set, the phase image data set of the examination subject is acquired, and a substantially closed, planar contour is established in the phase image data set around the partial region, the planar contour having a contour area with a width of at least one pixel of the phase image data set. The phase values in the partial region are determined with the assumption that the spatial curve of the background phase is a harmonic or quasi-harmonic function, the phase values of the pixels in the partial region being determined based on the phase values in the planar contour.
摘要:
In a method to determine a background phase in phase values of a phase image data set that is acquired from an examination subject, wherein the background phase is determined in a partial region of the phase image data set, the phase image data set of the examination subject is acquired, and a substantially closed, planar contour is established in the phase image data set around the partial region, the planar contour having a contour area with a width of at least one pixel of the phase image data set. The phase values in the partial region are determined with the assumption that the spatial curve of the background phase is a harmonic or quasi-harmonic function, the phase values of the pixels in the partial region being determined based on the phase values in the planar contour.
摘要:
In a method and system for administering a dispersible medical agent to a subject, a volume of medical agent is delivered in vivo to a subject in a substantially non-dispersed state, at a localized site in tissue of the subject. Contemporaneously with administration of the medical agent to the localized site, energy from an energy source is introduced into only adjacent tissue surrounding the localized site. The energy produces a cellular modification of the adjacent tissue that makes the adjacent tissue substantially impermeable to passage of the medical agent therethrough, so the medical agent is encapsulated and is prevented from dispersing into tissue outside of the encapsulation.
摘要:
In order to reduce reflection and heating of a high intensity focused ultrasound (HIFU) beam following a region of interest in tissue to which an HIFU beam was administered, at least two layers of aquasonic gel are applied at a tissue/air interface following the region of interest and the focus in a direction of propagation of the HIFU beam. A first of the two aquasonic gel layers is a foamed aquasonic gel layer, and a second of the two layers is substantially bubble-free aquasonic gel. The layer of foamed aquasonic gel is placed directly adjacent the tissue/air interface, and the layer of substantially bubble-free aquasonic gel is placed over the layer of foamed aquasonic gel, at a side thereof facing away from the tissue/air interface.
摘要:
In order to decrease collateral heating of ribs and tissue surrounding the ribs in a patient during high-intensity focused ultrasound (HIFU) therapy, shielding material may be positioned on or adjacent to an external surface of the patient and aligned with ribs to be protected using a magnetic resonance imaging (MRI) system. The MRI system may be used to image the shielding material and the ribs to be protected, and an error of alignment between the ribs to be protected and the shielding material may be determined based on the images. The shielding or masking material may be repositioned based on the determined error of alignment, images of the shielding material and the ribs to be protected may be reacquired, and the error of alignment may be redetermined based on the reacquired images until the shielding material is aligned with the ribs to be protected.
摘要:
In a method and magnetic resonance (MR) apparatus for implementing an MR-guided procedure, an MR-compatible digital camera is placed in the patient receiving opening of the MR data acquisition unit that is operated to acquire MR data for reconstructing images that are used to guide the MR-guided intervention. The digital camera is operated to obtain digital images of the exterior of the patient, from which motion of the patient is detectable. The images are analyzed in a processor to identify therefrom the motion of the patient and the result of the analysis is represented as a processor output that is used to control the timing, with respect to the motion of the examination subject, of the occurrence of at least one event in the MR-guided procedure. One important application is respiratory gating/triggering of HIFU sonication for the treatment of moving organs.
摘要:
An ultrasound transducer for use in a magnetic resonance system is provided with an RF shield formed of electrically conductive material and having an interior cavity configured to receive the ultrasound transducer therein. The RF shield substantially precludes coupling between the ultrasound transducer, and any coupling medium that is employed, and the transmission and reception coils of the magnetic resonance system.
摘要:
An RF active device, immersed in liquid medium, for use in a magnetic resonance system is provided with an RF shield formed of electrically conductive material and having an interior cavity configured to receive the RF active device therein. The RF shield substantially precludes coupling between the active device, and any coupling medium that is employed, and the transmission and reception coils of the magnetic resonance system.
摘要:
In a method for temperature control in MR-guided administration of ultrasound, ultrasound therapy is administered to a patient at an in vivo site by emitting focused ultrasound into the site at multiple foci with a multi-focus ultrasound therapy device. The temperature is monitored in a localized region of an examination subject in which the site is located during the therapy in real-time by MR thermometry. From the MR thermometry, characteristics of the temperature distribution in the monitored region of the examination subject are automatically identified. Temperature control is implemented by regulating the energy output of the ultrasound therapy device, according to a rapidly converging master equation.
摘要:
In a method for temperature control in MR-guided administration of ultrasound, ultrasound therapy is administered to a patient at an in vivo site by emitting focused ultrasound into the site at multiple foci with a multi-focus ultrasound therapy device. The temperature is monitored in a localized region of an examination subject in which the site is located firing said therapy in real-time by MR thermometry. From the MR thermometry, characteristics of the temperature distribution in the monitored region of the examination subject are automatically identified. Temperature control is implemented by regulating the energy output of the ultrasound therapy device, according to a rapidly converging master equation.