Koninklijke Philips Corporation N.v.

David Leslie Foxall

Dee H Wu

Wayne R Dannels

Francis H Bearden

Melanie Suzanne Kotys

John Carlon

Robert Gauss

Baolian Yang

Agus Priatna

Sara M Oberrecht

Ajit Devaraj

Chun Jiang Xiao

Wim M Prins

Sara Hagey

A system () for quality assurance of a magnetic resonance (MR) imaging device () used in magnetic resonance based radiation therapy planning includes a phantom () weighing less than 18.2 kg (40 lbs.). The phantom includes a three dimensional spatial distribution of MR and CT imagable elements () located in an MR and CT inert foam support (), and an MR and CT inert external support structure () which surrounds and hermetically seals the foam support. The spatial distribution is sized to completely fill an imaging volume of the magnetic resonance imaging device.

Quality assurance apparatus and method for magnetic resonance based radiation therapy planning

An image dataset comprises multiple shots of imaging data acquired using a magnetic resonance imaging (MRI) scanner (). The signal power of each shot of the image dataset is normalized () to a reference signal power to generate a power normalized shot representation having total signal power matching the reference signal power. A reconstructed image is generated () from the power normalized shot representations. Odd/even phase correction () may also be performed on the image dataset. The phase correction, normalizing, and generating operations are suitably performed by an electronic data processing device ().

Multiple shot magnetic resonance imaging with ghosting stability correction

A magnetic resonance (MR) generating a static (BO) magnetic field of 5 Tesla or higher controller is configured to control an MR scanner to perform an MR sequence () including: performing an excitation/localization sub-sequence () on a subject disposed in the static (BO) magnetic field generated by the MR scanner to excite 1H polarization in a selected spatial region of the subject; performinga polarization transfer sub-sequence () to transfer localized 1H polarization generated by the excitation/localization sub-sequence to a selected species of non-proton nuclei; and performing a magnetic resonance spectroscopy (MRS) readout sub-sequence () to acquire MRS data for the selected species of non-proton nuclei in the selected spatial region of the subject. The polarization transfer sub-sequence includes a pair of phasedistortion canceling trapezoidal 180&#xb0; refocusing pulses () operating on the selected species of non-proton nuclei.

Broad bandwidth magnetic resonance spectroscopy at high static (B0) magnetic field using polarization transfer

In a magnetic resonance data acquisition method, magnetic resonance is excited () in an observed nuclear species. Magnetic resonance data of the observed nuclear species are acquired (). A plurality of different broadband decoupling radio frequency pulses () configured to decouple a coupled nuclear species from the observed nuclear species are applied. Each broadband decoupling radio frequency pulse has a different or randomized or pseudorandomized amplitude () as a function of time. Each broadband decoupling radio frequency pulse has about the same peak power, pulse duration, and frequency spread. The differences between the broadband decoupling radio frequency pulses are effective to substantially suppress cycling sidebands.

Low power broadband spin decoupling

When scanning a patient to generate an image thereof, radio frequency (RF) coil modules are scalably coupled to each other using a plurality of clips to form flat or polygonal coil arrays that are placed on or around the patient or a portion thereof. A user assesses the volume to be imaged, identifies a coil array configuration of suitable size and shape and employs clips of one or more pre-determined angles to construct the identified coil array configuration, which is placed on or about the volume. Coil modules are coupled to a preamplifier interface box (PIB), which provides preamplified coil signal(s) to a patient imaging device, such as an MRI scanner. Small arrays are constructible to accommodate pediatric patients and/or smaller animals. Modules are hermetically sealed, can be sanitized between uses, and discarded at end-of-life. In one aspect, the modular coil array, clips, and PIB are maintained in an isolated contamination zone, separate from the patient imaging device.

Integrated system of MRI RF loop coils plus spacing fixtures with biocontainment uses

In a method for shimming a magnetic resonance imaging scanner (), at least one of fat suppression and blood suppression is performed to suppress magnetic resonance from a corresponding at least one of fat and blood. First and second magnetic resonance echoes emanating from a generally columnar volume are measured. The measurements of the first and second magnetic resonance echoes () are reconstructed () into corresponding first and second generally columnar projection images (). The first and second generally columnar projection images are combined () to produce a magnetic field profile () of the generally columnar volume. Selected magnetic field parameters are extracted () from the magnetic field profile. Shim currents are computed () from the selected magnetic field parameters. The shim currents are applied to magnetic field coils ().

Shimming of MRI scanner involving fat suppression and/or black blood preparation

A magnetic resonance imaging (MRI) apparatus () acquires a plurality of parametric images () with at least one varying imaging parameter. A parametric map () is constructed from the plurality of parametric images (). At least one pilot parameter () is identified from at least the parametric map (). The at least one identified pilot parameter () includes at least a volume of interest for a diagnostic image. A contrast agent () is administered to the patient (). The identified volume of interest is imaged during influx of the administered contrast agent () into the identified volume of interest. The imaging uses the at least one identified pilot parameter ().

Method and apparatus for evaluation of contrast agent uptake based on derived parametric images

To prepare magnetization for steady state magnetic resonance imaging, magnetic resonance is primed using a parameterized priming sequence (). The parameterized priming sequence () has a spectral offset parameter value () corresponding to a spectral offset of the steady state imaging. Subsequent to the priming, steady state magnetic resonance imaging data at the first spectral offset is acquired using a magnetic resonance imaging scanner (). A reconstruction processor () reconstructs the imaging data to generate an image representation. Preferably, the parameterized priming sequence () includes a longitudinal priming sequence () that prepares longitudinal magnetization in a state approximating a steady state longitudinal magnetization. A spoiler sequence () spoils transverse magnetization while retaining longitudinal magnetization. A transverse priming sequence () prepares traverse magnetization in a state approximating a steady state transverse magnetization.

Magnetization primer sequence for balanced steady state free precision imaging

A steady-state free precession (SSFP) sequence includes a large multiplicity of RF pulses ( ) with a relatively short repeat time or interpulse interval (TR) on the order of 2-10 milliseconds. After applying the RF pulses for a period of about 3 T , about 6 seconds, a steady-state is achieved. Thereafter, at least a phase-encode gradient ( ) and a read gradient ( ) are applied between each subsequent pair of adjoining RF pulses, a data line being generated during each read gradient pulse. For a 128 line image with a TR of 6 milliseconds, a set of data lines are generated in 768 milliseconds, about &frac34; of a second. As the data lines are generated, a spectral offset is adjusted by continuously adjusting an RF phase of an RF transmitter ( ) and an RF receiver ( ), with N sets of data lines being generated over 360&deg; of RF phase shift. Like corresponding data lines from each set offset an RF phase by 360&deg;/N are combined and Fourier transformed into an image representation. In this manner, N complete data sets are collected at different spectral offsets without intervening delay intervals to reestablish the steady-state, i.e., in 9 seconds instead of 27 seconds (for N&equals;4).

Sliding frequency steady-state precession imaging

A method of imaging a patient with an MRI scanner ( ) includes imaging a region of interest of the patient with the MRI scanner ( ) and acquiring image data resulting from the imaging. An image of the region of interest is reconstructed from the image data. The method also includes generating navigator echos during the imaging, collecting the navigator echos and deriving, from each navigator echo, a measurement of patient motion experience during the imaging. A historical record of the measurements is maintained. Parameters for the acquisition of image data are selected to compensate for motion, or specific image data is selected for reconstruction, based on the historical record.

Signal analysis for navigated magnetic resonance imaging

A method of imaging a subject with an MRI scanner ( ) includes positioning a region of interest of the subject in the MRI scanner ( ) and executing an echo planar imaging pulse sequence therewith. A signal (S) produced by the echo planar imaging pulse sequence is received. The signal (S) includes first and second distinct sets of echos. Each echo ( ) in the first set of echos coincides with a positive polarity read gradient ( ) of the echo planar imaging pulse sequence and each echo ( ) in the second set of echos coincides with a negative polarity read gradient ( ) of the echo planar imaging pulse sequence. The method further includes collecting into a first k-space matrix data corresponding to the first set of echos and collecting into a second k-space matrix data corresponding to the second set of echos. A first image of the region of interest is reconstructed from the data in the first k-space matrix, and a second image of the region of interest is reconstructed from the data in the second k-space matrix. Preferably, the two images are temporally offset from one another, and cine or fluoroscopic imaging is achieved by alternating the frames thereof between iteratively produced first and second images.

Multishot echo planar imaging fluoroscopic technique

A method of MRI includes supporting a subject in an examination region of an MRI scanner, and setting up a spin system with a net magnetization. An inversion pulse is applied which inverts the magnetization of the spin system in a selected volume of the subject. As the magnetization re-grows, a first set of raw data is generated by acquiring MR signals from a series of regions within the selected volume. For the first set of raw data, the series of regions are acquired in a first temporal order with respect to the inversion pulse. The inversion pulse is re-applied, and as the magnetization re-grows, a second set of raw data is generated in similar fashion to the first. However, for the second set of raw data, the series of regions are acquired in a second temporal order with respect to the inversion pulse. The second temporal order is different from the first temporal order. From the first and second sets of raw data, respectively, first and second sets of complex image data are generated. A complex phase correction factor is then determined and applied to one of, or both, the first and second sets of complex image data to thereby phase match the same. A combined image is generated via a pixel by pixel complex combination of the phase matched first and second sets of complex image data.

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Mentor, OH, United States of America

David Leslie Foxall