# US 2023/0054048 A1 · Mri apparatus and mri method

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- Number: US 2023/0054048 A1
- Document ID: US20230054048A1
- Status: Published application
- Kind: A1
- Application number: 17/819,348
- Filed: 2022-08-12
- Published: 2023-02-23
- Earliest claimed: 2021-08-17
- Assignees: Canon Medical Systems Corporation
- Applicants: Canon Medical Systems Corporation
- Inventors: Shinya OZAWA; Takeshi ISHIMOTO
- Web page: https://patentgrep.com/patent/US20230054048A1

## CPC

- G01R 33/543: {Control of the operation of the MR system, e.g. setting of acquisition parameters prior to or during MR data acquisition, dynamic shimming, use of one or more scout images for scan plane prescription (G01R33/546 takes precedence)}
- G01R 33/5673: {Gating or triggering based on a physiological signal other than an MR signal, e.g. ECG gating or motion monitoring using optical systems for monitoring the motion of a fiducial marker}
- A61B 5/055: involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
- A61B 5/1135: {by monitoring thoracic expansion}
- A61B 5/7289: {Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition}
- A61B 5/7292: {Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal}
- G01R 33/5602: {by filtering or weighting based on different relaxation times within the sample, e.g. T1 weighting using an inversion pulse}
- G01R 33/56509: {due to motion, displacement or flow, e.g. gradient moment nulling (G01R33/567 takes precedence)}
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

According to one embodiment, MRI apparatus includes processing circuitry and an imaging device. The processing circuitry is configured to acquire at least one of body size information relating to a size of an object and breath-hold information relating to a breath-holdable time of the object. The processing circuitry is further configured to determine an imaging condition to be performed on the object based on the at least one of the body size information and the breath-hold information. The imaging device performs imaging of the object in accordance with the determined imaging condition.

## Claims

### Claim 1

An MRI apparatus comprising:
processing circuitry configured to
acquire at least one of body size information relating to a size of an object and breath-hold information relating to a breath-holdable time of the object, and
determine an imaging condition to be performed on the subject based on the at least one of the body size information and the breath-hold information; and
an imaging device imaging the object in accordance with the determined imaging condition.

### Claim 2 (depends on 1)

The MRI apparatus according to claim 1, wherein the processing circuitry acquires the body size information based on a positioning image of the object that is obtained prior to obtaining an image for diagnosis of the object.

### Claim 3 (depends on 1)

The MRI apparatus according to claim 1, wherein the processing circuitry acquires the body size information based on an optical camera image of the object taken by the optical camera.

### Claim 4 (depends on 1)

The MRI apparatus according to claim 1, wherein the body size information acquired by the processing circuitry includes at least one of a size of the object on a coronal plane, a size of the object on a sagittal plane, a size of the object on an axial plane, a thickness of the object in a dorsoventral direction, and a width of the object in a left-right direction of the object.

### Claim 5 (depends on 1)

The MRI apparatus according to claim 1, wherein the processing circuitry acquires the breath-hold information based on a respiratory waveform of the object measured by a respiratory sensor.

### Claim 6 (depends on 5)

The MRI apparatus according to claim 5, wherein the respiratory waveform is measured during imaging of a positioning image of the object, which is acquired prior to acquisition of an image for diagnosis of the object.

### Claim 7 (depends on 1)

The MRI apparatus according to claim 1, wherein the processing circuitry is further configured to
refer to an imaging preset list in which a plurality of imaging methods and a plurality of imaging conditions corresponding to each of the plurality of imaging methods are predetermined; and
based on the at least one of the body size information and the breath-hold information, select an imaging condition corresponding to the object from the plurality of imaging conditions for each imaging method, and determine the selected imaging condition as the imaging condition to be performed.

### Claim 8 (depends on 7)

The MRI apparatus according to claim 7, wherein:
the imaging preset list includes a preset list for breath-hold imaging corresponding to breath-hold imaging; and
each of the plurality of imaging conditions for each imaging method predetermined in the preset list for breath-hold imaging is corresponding to each combination of a plurality of body size categories classified according to the object size and a plurality of breath-hold categories classified according to the breath-holdable time of the object.

### Claim 9 (depends on 8)

The MRI apparatus according to claim 8, wherein the processing circuitry is further configured to:
select a body size category corresponding to the object from the plurality of body size categories based on the acquired body size information of the object, and select a breath-hold category corresponding to the object from the plurality of breath-hold categories based on the acquired breath-hold information of the object; and
determine an imaging condition corresponding to the selected body size category and the selected breath-hold category as the imaging condition to be performed.

### Claim 10 (depends on 8)

The MRI apparatus according to claim 8, wherein the processing circuitry is further configured to:
calculate a breath-holdable time of the object based on the acquired breath-hold information of the object;
compare a plurality of breath-hold imaging times corresponding to the plurality of breath-hold categories with the breath-holdable time of the object; and
when the breath-hold imaging time of the object is shorter than the shortest breath-hold imaging time of the plurality of breath-hold imaging times, further refer to a preset list for free-breathing imaging, which is another preset list included in the imaging preset list and corresponds to an imaging performed under free breathing.

### Claim 11 (depends on 10)

The MRI apparatus according to claim 10, wherein:
the plurality of imaging conditions for each imaging method predetermined in the preset list for free-breathing imaging corresponds to the plurality of body size categories classified according to the object size; and
the processing circuitry is configured to select a body size category corresponding to the object from the plurality of body size categories based on the acquired body size information of the object, and determine an imaging condition corresponding to the selected body size category as the imaging condition to be performed.

### Claim 12 (depends on 10)

The MRI apparatus according to claim 10, wherein the imaging performed under free breathing is imaging including either respiratory synchronous imaging, which is imaging synchronized with a signal from a respiratory sensor, or diaphragm synchronous imaging, which is imaging using a navigator echo.

### Claim 13 (depends on 8)

The MRI apparatus according to claim 8, wherein each of the plurality of imaging conditions differs in at least one parameter of number of slices, slice thickness, slice spacing, FOV, and matrix size for each body size category.

### Claim 14 (depends on 8)

The MRI apparatus according to claim 8, wherein each of the plurality of imaging conditions differs in at least one parameter of the number of slices, slice thickness, slice spacing, matrix size, repetition rate TR, and speed-up rate in parallel imaging for each of the breath-hold categories.

### Claim 15

An MRI method comprising:
acquiring at least one of body size information relating to a size of an object and breath-hold information relating to a breath-holdable time of the object, and
determining an imaging condition to be performed on the object based on the at least one of the body size information and the breath-hold information; and
imaging the object in accordance with the determined imaging condition.