Patent classifications
G01R33/5613
Multi-state magnetic resonance fingerprinting
The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142) from a subject (118) within a measurement zone (108). The magnetic resonance imaging system (100) comprises: a processor (130) for controlling the magnetic resonance imaging system (100) and a memory (136) storing machine executable instructions (150, 152, 154), pulse sequence commands (140) and a dictionary (144). The pulse sequence commands (140) are configured for controlling the magnetic resonance imaging system (100) to acquire the magnetic resonance data (142) of multiple steady state free precession (SSFP) states per repetition time. The pulse sequence commands (140) are further configured for controlling the magnetic resonance imaging system (100) to acquire the magnetic resonance data (142) of the multiple steady state free precession (SSFP) states according to a magnetic resonance fingerprinting protocol. The dictionary (144) comprises a plurality of tissue parameter sets. Each tissue parameter set is assigned with signal evolution data pre-calculated for multiple SSFP states.
Systems and methods for low-field fast spin echo imaging
A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.
MAGNETIC RESONANCE IMAGING APPARATUS, IMAGE GENERATING METHOD AND COMPUTER-READABLE NON-VOLATILE STORAGE MEDIUM STORING MEDICAL IMAGE PROCESSING PROGRAM
An MRI apparatus according to an embodiment includes sequence controlling circuitry, in a first transition period, repeating application of a first MT pulse and acquisition of a first MR signal to a first frequency region being a part of a k-space; in the first steady state, repeating application of the first MT pulse and acquisition of a second MR signal to a second frequency region of the k-space, frequency in second frequency region being lower than frequency in the first frequency region; and in a second transition period, repeating application of a second MT pulse and acquisition of a third MR signal to a third frequency region being another part of the k-space, frequency in the third frequency region being higher than the frequency in the second frequency region, and processing circuitry generating one MR image on basis of the first, second, and third MR signal.
MAGNETIC RESONANCE IMAGING APPARATUS FOR MEASURING MAGNETIC RESONANCE IMAGING PARAMETERS AND METHOD OF OPERATING THE SAME
The present disclosure relates to magnetic resonance imaging technology for simultaneously measuring a plurality of magnetic resonance imaging parameters. According to one embodiment of the present disclosure, a magnetic resonance imaging apparatus includes a data collector for alternately collecting a steady-state-free-precession (SSFP)-FID signal and an SSFP-ECHO signal within a time of repetition to obtain AUSFIDE (alternating unbalanced SSFP-FID & SSFP-ECHO) image data; a data processor for reconstructing a magnitude image and a phase image for each of the SSFP-FID signal and the SSFP-ECHO signal in the AUSFIDE (alternating unbalanced SSFP-FID & SSFP-ECHO) image data and processing the AUSFIDE (alternating unbalanced SSFP-FID & SSFP-ECHO) image data using the reconstructed magnitude images and phase images; and a parameter measuring device for measuring a plurality of magnetic resonance imaging parameters using a plurality of echo data based on the processed AUSFIDE (alternating unbalanced SSFP-FID & SSFP-ECHO) image data.
Systems and Methods for Spiral-In-Out Low Field MRI Scans
Systems and methods for performing ungated magnetic resonance imaging are disclosed herein. A method includes producing magnetic resonance image MRI data by scanning a target in a low magnetic field with a pulse sequence having a spiral trajectory; sampling k-space data from respective scans in the low magnetic field and receiving at least one field map data acquisition and a series of MRI data acquisitions from the respective scans; forming a field map and multiple sensitivity maps in image space from the field map data acquisition; forming target k-space data with the series of MRI data acquisitions; forming initial magnetic resonance images in the image domain by applying a Non-Uniform Fast Fourier Transform to the target k-space data; and forming reconstructed images with a low rank plus sparse (L+S) reconstruction algorithm applied to the initial magnetic resonance images.
System and method for recording a positron emission tomography image data set
In a method for recording a PET image data set, an overall recording area is moved continuously through the FOV at a constant movement speed, an attenuation map of the overall recording area being used to reconstruct the PET image data record from the PET raw data. The magnetic resonance data of a slice of the patient currently located within the FOV and movement status information relating to a cyclical movement of the patient are recorded simultaneously with recording the PET raw data. A movement status class is assigned to the PET raw data and the magnetic resonance data in each case. Using the magnetic resonance data assigned to the different movement status classes, attenuation maps of the patient are determined for the different movement status classes and applied to the PET raw data assigned to the corresponding movement status class to reconstruct the PET image data set.
SYSTEMS AND METHODS FOR LOW-FIELD FAST SPIN ECHO IMAGING
A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.
MAGNETIC RESONANCE IMAGING METHOD AND DEVICE
A method for generating a magnetic resonance imaging, MRI, image of a subject including applying a magnetic field B.sub.0 to the subject, applying a sequence of electromagnetic pulses to the subject, applying further magnetic field gradients in addition to the magnetic field B.sub.0, the magnetic field including first gradients and at least one second gradient; measuring signal echoes produced by the object in response to the electromagnetic pulses and the first and second magnetic field gradients; acquiring image data at a first spatial resolution from the signal echo produced by the object in response to the electromagnetic pulses and the first and second magnetic field gradients, and combining the image data acquired from signal echoes in order to produce at least one image of the object at a second spatial resolution.
Method and device for magnetic resonance imaging, and corresponding computer program product
In a Method and a device for magnetic resonance imaging of a subject using a spoiled gradient echo sequence, a B.sub.0 magnetic field strength of at most 1.5 T is used during the sequence. As part of the sequence a slice select gradient acting as a spoil gradient is played out. Substantially simultaneously with the slice select gradient a predetermined RF pulse is played out in the sequence, wherein a time-bandwidth product of the RF pulse is set so that a majority of the energy of the RF pulse is transmitted in its central main lobe.
METHOD FOR ACQUIRING A MAGNETIC RESONANCE IMAGE DATASET OF A SUBJECT AND MAGNETIC RESONANCE IMAGING SYSTEM
The invention relates to a method for acquiring a magnetic resonance image dataset of a subject, a magnetic resonance imaging system and a non-transitory computer-readable medium. The method comprises the steps: (a) determining scan conditions relating to an imaging protocol which is to be carried out on the subject; (b) based on the scan conditions and/or on predetermined reference parameters, determining whether at least one imaging preparation procedure may be omitted or accelerated to have a shortened duration; (c) depending on the determination of step (b), omitting or carrying out the least one imaging preparation procedure at the standard or at the shortened duration; (d) carrying out the imaging protocol in order to acquire the magnetic resonance image dataset.