# US 10,945,697 B2 · X-ray CT apparatus

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- Number: US 10,945,697 B2
- Document ID: US10945697B2
- Status: Granted
- Kind: B2
- Application number: 16/177,755
- Filed: 2018-11-01
- Published: 2019-03-07
- Granted: 2021-03-16
- Earliest claimed: 2016-06-06
- Assignees: Canon Medical Systems Corporation
- Applicants: Canon Medical Systems Corporation
- Inventors: Takahiro Goto; Shinsuke Tsukagoshi
- Web page: https://patentgrep.com/patent/US10945697B2

## CPC

- A61B 6/544: {dependent on patient size}
- A61B 6/027: {characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral}
- A61B 6/032: {Transmission computed tomography [CT]}
- A61B 6/0407: {Supports, e.g. tables or beds, for the body or parts of the body}
- A61B 6/481: {involving the use of contrast agents}
- A61B 6/5211: {involving processing of medical diagnostic data}
- A61B 6/545: {involving automatic set-up of acquisition parameters}
- G06T 7/11: Region-based segmentation
- G06T 7/13: Edge detection
- G16H 50/20: for computer-aided diagnosis, e.g. based on medical expert systems
- A61B 6/0487: {Motor-assisted positioning}
- A61B 6/463: {characterised by displaying multiple images or images and diagnostic data on one display}
- G06T 2207/10081: Computed x-ray tomography [CT]
- G06T 2207/20128: Atlas-based segmentation
- G06T 2207/30004: Biomedical image processing
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA

## Abstract

An X-ray computed tomography (CT) apparatus according to an embodiment includes processing circuitry. The processing circuitry is configured to generate image data based on a detection result obtained by detecting X-rays transmitted through a subject with a detector. The processing circuitry is configured to specify a boundary between a first region and a second region in the image data, based on anatomical landmarks in the image data, and adjust setting of scan conditions relating to a tube current value in accordance with information relating to a position of the boundary.

## Claims

### Claim 1

An X-ray computed tomography (CT) apparatus comprising:
processing circuitry configured to
generate image data based on a detection result obtained by detecting X-rays transmitted through a subject with a detector; and
specify a boundary between a first region and a second region in the image data, based on anatomical landmarks in the image data, and adjust setting of scan conditions relating to a tube current value in accordance with a position of the boundary and a position of an end portion of a satiric range where the tube current value is set by Auto Exposure Control (AEC).

### Claim 2 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is configured to adjust a scan start position such that the position of the boundary agrees with an end portion of an imaging range corresponding to the setting range equal to or larger than a minimum setting range, in a slice direction.

### Claim 3 (depends on 2)

The X-ray CT apparatus according to claim 2, wherein the processing circuitry is configured to set, based on a plurality of pieces of body thickness information on the subject in an imaging range determined by setting of the scan start position, the tube current value in the imaging range.

### Claim 4 (depends on 3)

The X-ray CT apparatus according to claim 3, wherein the processing circuitry is configured to set the tube current value in the imaging range, based on a maximum body thickness or an average body thickness of the pieces of body thickness information on the subject in the imaging range.

### Claim 5 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is configured to adjust a scan start position such that the position of the boundary agrees with an end portion of an imaging range corresponding to a rotation period of an X-ray tube, in a slice direction.

### Claim 6 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein, when the detection result is detected by helical scan, the processing circuitry is configured to control a rotary frame rotating and moving an X-ray tube, a relative positional relation between a bed on which the subject lies down and a gantry, or acquisition lines of the detector such that the position of the boundary agrees with an end portion of an imaging range corresponding to a rotation period of the X-ray tube.

### Claim 7 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein, when the detection result is detected by wide volume scan, the processing circuitry is configured to control acquisition lines of the detector such that the position of the boundary agrees with an end portion of an imaging range corresponding to a rotation period of the X-ray tube.

### Claim 8 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is configured to acquire the anatomical landmarks in the image data by matching the image data with anatomical reference positions.

### Claim 9 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is configured to adjust a position of an imaging range for the first region and the second region, based on respective tissue weighting factors of the first region and the second region.

### Claim 10 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is further configured to set one of a dose reduction mode and an image quality priority mode, wherein
the processing circuitry is configured to set an end portion of a region with a lower CT value in the first region and the second region as the boundary, when the dose reduction mode is set and the first region and the second region overlap in an XY cross section.

### Claim 11 (depends on 1)

The X-ray CT apparatus according to claim 1, wherein the processing circuitry is further configured to set one of a dose reduction mode and an image quality priority mode, wherein
the processing circuitry is configured to set an end portion of a region with a higher CT value in the first region and the second region as the boundary, when the image quality priority mode is set and the first region and the second region overlap in an XY cross section.
