# US 2025/0082284 A1 · Filter System And Method For Imaging A Subject

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- Number: US 2025/0082284 A1
- Document ID: US20250082284A1
- Status: Published application
- Kind: A1
- Application number: 18/956,043
- Filed: 2024-11-22
- Published: 2025-03-13
- Earliest claimed: 2020-10-26
- Assignees: Medtronic Navigation, Inc.
- Applicants: Medtronic Navigation, Inc.
- Inventors: Patrick A. HELM; Seunghoon NAM; Shuanghe SHI
- Web page: https://patentgrep.com/patent/US20250082284A1

## CPC

- A61B 6/032: {Transmission computed tomography [CT]}
- A61B 6/4035: {the source being combined with a filter or grating}
- A61B 6/4085: {Cone-beams}
- A61B 6/482: {involving multiple energy imaging}
- G01T 1/161: Applications in the field of nuclear medicine, e.g. in vivo counting {(apparatus for radiation diagnosis A61B6/00)}
- G06T 11/008
- G06T 17/00: Three-dimensional [3D] modelling for computer graphics
- G21K 1/10: Scattering devices; Absorbing devices; Ionising radiation filters
- A61B 6/12: Arrangements for detecting or locating foreign bodies
- A61B 6/4405: {the apparatus being movable or portable, e.g. handheld or mounted on a trolley}
- A61B 6/5282: {due to scatter}
- A61B 8/5207: {involving processing of raw data to produce diagnostic data, e.g. for generating an image}
- G06T 2211/408: Dual energy
- G06T 2211/424: Iterative
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00)
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES

## Abstract

A method and system is disclosed for acquiring image data of a subject. The image data can be collected using an imaging system with a selected filtering characteristic. The image data can be reconstructed using reconstruction techniques.

## Claims

### Claim 1

An imaging system, comprising:
a source configured to emit a broad spectrum beam;
a detector; and
a filter assembly, including:
a filter member configured to limit a transmission of the broad spectrum beam to form a limited spectrum beam, and
a filter carrier configured to move the filter member relative to the broad spectrum beam;
wherein the detector is configured to detect the limited spectrum beam due to the filter and the broad spectrum beam from the source.

### Claim 2 (depends on 1)

The system of claim 1, wherein the broad spectrum beam is a x-ray beam that includes photons with a range of energies having a peak up to about 140 kVp.

### Claim 3 (depends on 2)

The system of claim 2, wherein the filter member includes a first filter member and a second filter member.

### Claim 4 (depends on 3)

The system of claim 3, wherein the first filter member limits or eliminates passage of low-energy x-ray photons to form a first energy spectra.

### Claim 5 (depends on 4)

The system of claim 4, wherein the second filter member limits or eliminates passage of a different proportion of low energy x-ray photons to form a second energy spectra that has a higher HVL than the first energy spectra.

### Claim 6 (depends on 1)

The system of claim 1, wherein a dual energy projection of a subject is acquired by having the broad spectrum beam occluded by the filter member.

### Claim 7 (depends on 1)

The system of claim 1, wherein the filter assembly includes a control to selectively position of the filter member in a path of the beam from the source to the detector.

### Claim 8 (depends on 1)

The imaging system of claim 1, wherein the broad spectrum beam has an x-ray with a distribution of energy of about 40 keV to about 140 keV.

### Claim 9 (depends on 8)

The imaging system of claim 8, wherein filter member includes a first filter member and a second filter member;
wherein the first filter member and the second filter member are selectively and separately placed between the source and the detector;
wherein the first filter member limits or eliminates passage of a proportion of low-energy x-ray photons;
wherein the second filter member further limits or eliminates passage a second proportion of low-energy x-ray photons.

### Claim 10

An imaging system configured to acquire a selected dose x-ray image projections of a subject, comprising:
a source configured to emit x-rays as a whole beam with a first energy spectra;
a filter assembly, including:
a filter member configured to limit a transmission x-rays to a filtered beam with a second energy spectra that has a different HVL than the first energy spectra,
a filter carrier configured to move the filter member relative to the whole beam;
a detector configured to detect the whole beam and the filtered beam;
a control system configured to control the position of the filter member with the filter carrier to selectively acquire projections of the subject;
wherein the control system is configured to execute instructions to control movement of the filter carrier to position the filter member in filtering position and a non-filtering position;
wherein the filter member limits the whole beam to the filtered beam in the filtering position;
wherein a selected number of projections are acquired to reconstruct a model of the subject.

### Claim 11 (depends on 10)

The system of claim 10, further comprising:
a reconstruction system configured to reconstruct the model of the subject with image data acquired with the whole beam and the filtered beam for a reduced x-ray dose image acquisition;
wherein the filtered beam may include a lower dose of x-rays relative to the whole beam.

### Claim 12 (depends on 11)

The system of claim 11, wherein the filter member is configured to reduce the intensity of the whole beam to the filtered beam;
wherein the filtered beam includes an HVL that about is about 40% to about 60% of the whole beam.

### Claim 13 (depends on 11)

The system of claim 11, wherein the filtered beam is operable with the detector to identify edges of selected portion of the subject.

### Claim 14 (depends on 11)

The system of claim 11, wherein the filtered beam exposes the subject to about 30% to about 60% less intensity of x-rays relative to the whole beam during an acquisition of a selected number of projections.

### Claim 15 (depends on 11)

The system of claim 11, wherein the control system is configured to operate the source and the detector to collect acquisitions of the subject at about 360 degrees around the subject.

### Claim 16 (depends on 15)

The system of claim 15, wherein the filtered beam is active to acquire a selected number of projections of the subject during a rotation of the source and the detector relative to the subject.

### Claim 17 (depends on 10)

The system of claim 10, wherein the filter member is formed of x-ray attenuating materials, including at least one of aluminum, copper, tin, or ceramics.

### Claim 18

A method of acquiring a limited x-ray dose image projection of a subject, comprising:
acquiring image data at a plurality of positions relative to the subject;
operating a source to emit x-rays as a whole beam at a sub-plurality of positions of the plurality of positions relative to the subject;
controlling a filter assembly to move a filter member into the emitter whole beam to form a filtered beam,
detecting with a detector the whole beam and the filtered beam; and
executing instructions with a processor module to reconstruct a model of a selected portion of the subject with image data acquisition of the subject using both the whole beam and the filtered beam.

### Claim 19 (depends on 18)

The method of claim 18, wherein controlling the filter assembly, further comprises:
executing instructions with a controller to move a filter carrier;
wherein the filter carrier holds the filter member and is moveable relative to the whole beam.

### Claim 20 (depends on 19)

The method of claim 19, further comprising:
forming the filtered beam to have a filtered beam HVL that is about 40% to about 60% different than a whole beam HVL of the whole beam.

### Claim 21 (depends on 18)

The method of claim 18, further comprising:
moving the source around the subject.

### Claim 22 (depends on 21)

The method of claim 21, wherein the sub-plurality of positions is a first sub-plurality of positions, wherein the plurality of positions includes a second sub-plurality of positions, and wherein the low power beam is detected to acquire image data of the subject at the second sub-plurality of positions.