G01R33/567

RESPIRATORY BIOFEEDBACK FOR MRI-GUIDED RADIOTHERAPY
20220338751 · 2022-10-27 ·

Disclosed is a medical system (100, 500) that comprises a radiotherapy system (102) configured for controllably irradiating a target volume (114) within an irradiation zone (112); a subject support (120) configured for supporting at least a ventral region (124) of a subject (122) within the irradiation zone; a breath monitor system (132, 132′) configured for providing a motion signal (154, 158) descriptive of subject breathing motion; and a subject display (130, 130′) configured for displaying a breathing phase indicator (160, 160′) to the subject when supported by the subject support. Execution of the machine executable instructions (150) causes a processor (142) controlling the medical system to receive (200) a time resolved magnetic resonance imaging dataset (152) synchronized to a measured motion signal (154). Execution of the machine executable instructions further causes the processor to repeatedly: determine (202) a desired motion signal (156) by temporally stepping through the measured motion signal; acquire (204) a current motion signal (158) using the breath monitor system; render (206) the breathing phase indicator on the display, wherein the breathing phase indicator is configured to indicate a difference (700) between the desired motion signal and the measured motion signal; and generate (208) control commands (162) configured for controlling targeting of the radio therapy system using a first portion of the time resolved magnetic resonance imaging dataset synchronized to the desired motion signal or a second portion of the time resolved magnetic resonance imaging dataset referenced by the current motion signal.

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

T1-weighted turbo-spin-echo MRI sequence for producing high quality dark blood images at high heart rates
11604244 · 2023-03-14 · ·

A T1-weighted turbo-spin-echo magnetic resonance imaging system configured to capture data associated with a subject's heart during a time period and produce MR images has a dark-blood preparation module, a data capture module, and an image reconstruction module. The dark-blood preparation module performs dark-blood preparation through double inversion during some, but not all of the heartbeats within the time period. The data capture module configured performs data readouts to capture imaging data of an imaging slice during every heartbeat in which dark-blood preparation is performed. The data capture module also performs a steady state maintenance step during every heartbeat in which dark-blood preparation is not performed in order to maintain maximum T1-weighting. The image reconstruction module configured to reconstruct a T1-weighted image based on the imaging data.

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.

Magnetic Resonance Imaging System with Acoustic Warning Signal

Disclosed herein is a magnetic resonance imaging system (100) controlled by a processor (130). The execution of the machine executable instructions causes the processor to sort (200) multiple preparatory scan commands (142) into fixed duration preparatory scan commands (144) and indeterminate duration preparatory scan commands (146). The execution of the machine executable instructions further causes the processor to first control (202) the magnetic resonance imaging system with the indeterminate duration preparatory scan commands and then (204) with the fixed duration preparatory scan commands. The execution of the machine executable instructions further causes the processor to calculate (206) a gradient pulse starting time (160). The execution of the machine executable instructions further causes the processor to provide (208) the warning signal at a predetermined time (162) before the gradient pulse starting time. The execution of the machine executable instructions further causes the processor to control (210) the magnetic resonance imaging system with pulse sequence commands to acquire the k-space data such that the execution of the gradient coil pulse commands begins at the pulse starting time.

Medical image diagnosis apparatus

A medical image diagnosis apparatus according to an embodiment includes processing circuitry. The processing circuitry is configured to derive a subject-specific regression model that indicates a relationship among a cardiac cycle, systole, and diastole of the subject. The processing circuitry is configured to derive timing of a data acquisition in a synchronization imaging performed in synchronization with heartbeats of the heart of the subject, by using the derived regression model and electrocardiographic information of the subject obtained during an image taking process. The processing circuitry is configured to control the synchronization imaging so that the data acquisition is performed with the derived timing.

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.

Magnetic resonance imaging apparatus

In one embodiment, a magnetic resonance imaging apparatus includes: a scanner that includes a static magnetic field magnet configured to generate a static magnetic field, a gradient coil configured to generate a gradient magnetic field, and a WB (Whole Body) coil configured to apply an RF pulse to an object; and processing circuitry. The processing circuitry is configured to: set (i) a pulse sequence in which a sequence element is repeated, the sequence element including at least an inversion pulse and (ii) a data acquisition sequence executed after a delay time from the inversion pulse; and cause the scanner to execute the pulse sequence by using virtual gating.

Imaging and diagnostic methods, systems, and computer-readable media

One aspect of the present subject matter provides an imaging method including: receiving a trigger signal; after a period substantially equal to a trigger delay minus an inversion delay, applying a non-selective inversion radiofrequency pulse to a region of interest followed by a slice-selective reinversion radiofrequency pulse to a slice of the region of interest of a subject; and after lapse of the trigger delay commenced at the cardiac cycle signal, acquiring a plurality of time-resolved images of the slice of the region of interest from an imaging device.

Systems and methods for signal synchronization in MRI device

Systems and methods for MR signal synchronization may be provided. The method may include determining a time difference in a local clock generator at a coil side assembly compared to a system clock generator at a system side assembly. The method may include maintaining a constant phase difference between clock signals generated by the local clock generator and by the system clock generator by correcting the local clock generator based on the time difference. The method may include acquiring MR echo signals by scanning at least a part of a subject in response to the clock signal generated by the corrected local clock generator. The method may further include digitizing the MR echo signal at the coil side assembly.