G01R33/563

Automatic Determination of a Motion Parameter of the Heart

The disclosure relates to techniques for determining a motion parameter of a heart. A subset of a sequence of cardiac MR images is applied as a first input to a first trained convolutional neural network configured to determine, as a first output, a probability distribution of at least 2 anatomical landmarks. The sequence of cardiac MR images is cropped and realigned based on the at least 2 anatomical landmarks to determine a reframed and aligned sequence of new cardiac MR images showing the same orientation of the heart. The reframed and aligned sequence of new cardiac MR images is applied to a second trained convolutional neural network configured to determine, as a second output, a further probability distribution of the at least 2 anatomical landmarks in each new MR image of the reframed and aligned sequence, the motion parameter of the heart is determined based on the second output.

Acquisition of four dimensional magnetic resonance data during subject motion

The invention provides for a magnetic resonance imaging system (100, 200) comprising a memory (148) for storing machine executable instructions (150) and pulse sequence commands (152). The pulse sequence commands are configured for acquiring a four dimensional magnetic resonance data set (162) from an imaging region of interest (109). The four dimensional magnetic resonance data set is at least divided into three dimensional data magnetic resonance data sets (400, 402, 404, 406, 408) indexed by a repetitive motion phase of the subject. The three dimensional data magnetic resonance data sets are further at least divided into and indexed by k-space portions (410, 412, 414, 416, 418, 420, 422, 424, 426, 428, 430, 432, 434, 436). The magnetic resonance imaging system further comprises a processor (144) for controlling the magnetic resonance imaging system. Execution of the machine executable instructions causes the processor during a first operational portion (310) to iteratively: receive (300) a motion signal (156) descriptive of the repetitive motion phase; acquire (302) an initial k-space portion using the pulse sequence commands, wherein the initial k-space portion is selected from the k-space portions; store (304) the motion signal and the initial k-space portion in a buffer (158) for each iteration of the first operational portion; at least partially construct (306) a motion phase mapping (160) between the motion signal and the repetitive motion phase; and continue (308) the first operational portion until the motion phase mapping is complete. Execution of the machine executable instructions causes the processor to assign (312) the initial k-space portion for each iteration of the first operational portion in the temporary buffer to the four dimensional magnetic resonance data set using the motion phase mapping. Execution of the machine executable instructions causes the processor during a second operational portion (332) to iteratively: receive (314) the motion signal; determine (316) a predicted next motion phase using the motion signal and the motion phase mapping; select (318) a subsequent k-space portion (154) from the k-space portions of the four dimensional magnetic resonance data set using the predicted next motion phase; acquire (320) the subsequent k-space portion using the pulse sequence commands; rereceive (322) the motion signal; determine (324) a current motion phase using the re-received motion signal and the motion phase mapping; assign (326) the

Perfusion phantom for MRI and an apparatus, system and method for validating MR images of a phantom

A perfusion chamber for use in a phantom includes a waterproof housing containing a porous material defining fluid paths between pores and tubular channels within the porous material. A reservoir for use in a phantom, a pump mechanism for use within the bore of an MRI scanner, a phantom for use in an MRI scanner, and a method for calibrating a scanning device are disclosed. Also disclosed is apparatus for validating images of a phantom that includes: one or more sensors for coupling to a phantom to be imaged; a control/logging system configured to: collect sensor data during imaging of the phantom and pass this as input to a computer model; compare the image data with reference image data produced using the computer model; and return a pass score depending on the comparison. A system and method for verifying images of a phantom are also disclosed.

Perfusion phantom for MRI and an apparatus, system and method for validating MR images of a phantom

A perfusion chamber for use in a phantom includes a waterproof housing containing a porous material defining fluid paths between pores and tubular channels within the porous material. A reservoir for use in a phantom, a pump mechanism for use within the bore of an MRI scanner, a phantom for use in an MRI scanner, and a method for calibrating a scanning device are disclosed. Also disclosed is apparatus for validating images of a phantom that includes: one or more sensors for coupling to a phantom to be imaged; a control/logging system configured to: collect sensor data during imaging of the phantom and pass this as input to a computer model; compare the image data with reference image data produced using the computer model; and return a pass score depending on the comparison. A system and method for verifying images of a phantom are also disclosed.

Inflow-based pulse wave velocity profiling along the aorta using magnetic resonance imaging
11478159 · 2022-10-25 · ·

In a method and magnetic resonance (MR) apparatus for pulse wave velocity (PWV) measurement along the aorta of a subject using MR imaging, a multislice cardio synchronized segmented ciné MR data acquisition sequence is optimized in order to enhance inflow representation in the slice images, in order to make the multislice MR data acquisition sequence viable for clinical uses, so as to acquire intensity-based MR data from two transverse slices spaced from each other along the descending aorta. The respective intensities of relevant pixels in at least two respective slice images are analyzed in order to identify the arrival of a pulse wave in the respective slices by the onset of flow enhancement in the slices, represented by intensity changes in the pixels. From the onset of flow enhancement in the respective slice images, PWV is calculated. An electronic signal representing the calculated PWV is then provided from a computer.

MAGNETIC RESONANCE IMAGING APPARATUS, METHOD FOR CONTROLLING THE SAME, AND CONTROL PROGRAM OF MAGNETIC RESONANCE IMAGING APPARATUS
20230078113 · 2023-03-16 ·

An object of the invention is to perform MRI imaging which is less likely to be affected by a body motion without prolonging an imaging time. The control unit takes in images captured by the camera at a predetermined frame rate. The imaging pulse sequence is divided into small sequences at a time width corresponding to the frame rate of the camera. The control unit, before causing the imaging unit to execute one small sequence, detects a displacement of the subject with respect to a predetermined reference position or a motion speed of the subject based on an image of the latest frame, and causes the imaging unit to execute the small sequence when a detection result is within a predetermined allowable range and waits until an image of a next frame is taken in according to the frame rate without causing the imaging unit to execute the small sequence when the detection result exceeds the allowable range.

USING CARDIAC MOTION FOR BEAT-TO-BEAT OPTIMISATION OF VARYING AND CONSTANT FRACTIONS OF CARDIAC CYCLES IN SEGMENTED K-SPACE MRI ACQUISITIONS

A method for adapting, per cardiac cycle, the parameters governing interpolation of varying and non-interpolation of fixed fractions of each individual cardiac cycle is provided. A time series of data values associated with a cardiac cycle is received, and the time series is scaled to a reference cardiac cycle, wherein the scaling includes applying a model to the time series to generate a scaled time series of data values associated with the first cardiac cycle. The model is trained using the scaled time series.

3D OSCILLATING GRADIENT-PREPARED GRADIENT SPIN-ECHO IMAGING METHOD, AND DEVICE
20230125982 · 2023-04-27 ·

A method for 3D oscillating-gradient prepared gradient spin-echo imaging and a device. The imaging method comprises the following steps: first, using a global saturation module to destroy previous residual transverse magnetization; second, embedding a pair of trapezoidal cosine oscillating gradients into a 90°.sub.x-180°.sub.y-90°.sub.−x radiofrequency pulse by a diffusion encoding module, to separate diffusion encoding from signal acquisition; then, using a fat saturation module to suppress a fat signal; finally, acquiring a signal by means of gradient spin-echo readout, and correcting phase errors among multiple excitations by multiplexed sensitivity-encoding reconstruction. Compared with a 2D plane echo-based oscillating gradient diffusion sequence used on a 3T clinical system, a 3D oscillating-gradient prepared gradient spin-echo sequence effectively reduces the imaging time, improves the signal to noise ratio, and is beneficial to clinical transformation of time-dependent diffusion MRI technology

Information processing method, device, and system for evaluating blood vessels

A computerized information processing method for evaluating blood vessels is provided. The method includes acquiring a series of sequences of measurements, each at different time points in at least one cardiac cycle and at a different point along a blood vessel segment of a subject, generating corresponding profiles, calculating a transfer function for a subsegment between two selected points along a blood flow direction, and based thereon determining the physiological property of the subsegment. The measurements can contain information of blood velocity or blood pressure. A processing device and system implementing the information processing method are also provided. This approach can be used to evaluate arteries or veins and can be applied in screening, diagnosis, or prognosis of a variety of vascular diseases. For example, when combined with MRI scan, this approach can be used for non-invasively diagnosing pulmonary hypertension (PH) and chronic obstructive pulmonary disease (COPD), etc.

A MAGNETIC RESONANCE METHOD, SOFTWARE PRODUCT, AND SYSTEM FOR DETERMINING A DIFFUSION PROPAGATOR OR RELATED DIFFUSION PARAMETERS FOR SPIN-LABELLED PATRICLES
20230124954 · 2023-04-20 ·

The present disclosure relates to a computer implemented diffusion magnetic resonance method for determining a diffusion parameter for spin-labelled particles in a specimen. The method (100) comprises providing (110) a specimen and a magnetic resonance device arranged to measure magnetic resonance in said specimen; applying (120) at least one magnetic field gradient pulse sequence to said specimen, thereby spin-labelling a set of particles comprised in said specimen; obtaining (130) magnetic resonance measurement data corresponding to said at least one magnetic field gradient pulse sequence for said spin-labelled particles with said magnetic resonance device; determining (140) at least one diffusion parameter for said spin-labelled particles based on said obtained measurement data; wherein determining (140) said at least one diffusion parameter comprises forming for each diffusion parameter at least one Fourier transform representing said diffusion parameter based on said obtained measurement data; and wherein each magnetic field gradient pulse sequence comprises at least three gradient pulses wherein at least one gradient pulse is configured to introduce a phase shift in said spin-labelled particles based on their position in said specimen.