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AI Method for Sharpening Low-Dose PET Scans with Multi-Task Learning

This patent describes an AI method using a special type of neural network called a multi-task learning generative adversarial network (GAN) to improve the quality of medical images from low-dose PET scans, making them look like standard-dose scans.

Granted 2023ActiveExpires 2041Owned by Shenzhen Institutes of Advanced TechnologyInvented by Xin Liu, Na Zhang, Yongfeng YANG + 4 more

Original patent title: “Method and system for generating multi-task learning-type generative adversarial network for low-dose PET reconstruction”

Plain-English explanation by SahiLast reviewed · October 23, 2026

This patent describes an AI method using a special type of neural network called a multi-task learning generative adversarial network (GAN) to improve the quality of medical images from low-dose PET scans, making them look like standard-dose scans. Granted to Shenzhen Institutes of Advanced Technology in 2023 with 10 claims, and it is expected to expire in 2041.

Coverage

What does this patent actually cover?

The patent describes a method for creating an AI system that can take blurry, low-dose Positron Emission Tomography (PET) images and make them clearer, similar to standard-dose PET images. It starts by building a "U-Net type picture generator" by connecting an "encoder" and a "decoder" using "skip connections" (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). Then, it creates multiple "generative adversarial networks" (GANs) by pairing these picture generators with "discriminators" (Claim 1). These GANs learn in parallel, sharing basic information, forming a "first multi-task learning-type generative adversarial network." The system is trained using a "joint loss function" that combines L1 type loss and cross entropy loss, comparing the AI's output to high-quality standard-dose PET images (ClaimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → 1, 2). For example, if a patient receives a low-dose PET scan to reduce radiation exposure, this AI can process those images to produce diagnostic quality results.

The gap

What does this patent NOT cover?

  • Does not cover methods for reconstructing PET images without using a "U-Net type picture generator" with "skip connections" (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
  • Does not cover systems that use only a single generative adversarial network, as it specifies "a group of generative adversarial networks" and "plurality of picture generators" (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
  • Does not cover methods where the "plurality of discriminators" do not use an "input modality," a "tag image," and an "output result" as input (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
  • Does not cover methods that do not combine low-dose PET and MR images as input modalities for each GAN (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
  • Does not cover training methods that do not use a "joint loss function 1" combining L1 type loss and cross entropy loss functions (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1, 2).

These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.

Key facts

Patent numberUS 11756161
StatusActive
FieldBiotech & Medicine
AssigneeShenzhen Institutes of Advanced Technology
InventorsXin Liu, Na Zhang, Yongfeng YANG and 4 others
Filed2021
Granted2023
Expires2041
Claims10
Times cited0
LitigationNone on record
Value · $29K–$92KMinimal

What made this novel

The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → lies in combining multiple "U-Net type picture generators" with "discriminators" into a "multi-task learning-type generative adversarial network," where these networks learn in parallel and share information. This parallel learning, guided by a specific "joint loss function" that considers both L1 and cross-entropy losses, allows the system to effectively reconstruct high-quality images from very low-dose PET data, leveraging additional MR image input.

The Patent Drawing

Representative patent drawing for Method and system for generating multi-task learning-type generative adversarial network for low-dose PET reconstruction (US 11756161)
Representative figure · US 11756161All figures on Google Patents →
Method and system for generati…(Primary claim)healthcareai mlsoftwaremedical devices

Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.

Where you've seen this

Real-world examples

01

Medical imaging software for PET scanners

02

AI-powered diagnostic tools in oncology

03

Radiology workstations

04

Research platforms for medical image enhancement

Why it matters

The bigger picture

Positron Emission Tomography (PET) scans are crucial for diagnosing diseases like cancer, but they expose patients to radiation. This patent matters because it offers a way to get high-quality images from lower radiation doses, making PET scans safer and potentially more accessible. By improving image quality from low-dose data, it could lead to earlier and more accurate diagnoses with reduced patient risk.

Filed

June 7, 2021

Granted

September 12, 2023

Market context

Who's building on this

Companies in this space

Companies like Siemens Healthineers, GE Healthcare, Philips, and various AI startups in medical imaging (e.g., Qure.ai, Aidoc) are actively developing and integrating AI for image reconstruction and enhancement in PET and other modalities. Shenzhen Institutes of Advanced Technology, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, continues research in this area.

Market impact

This type of AI technology has a significant impact on the medical imaging market by enabling safer diagnostic procedures. It drives the development of new AI-powered features in PET scanners and radiology software, potentially reducing patient radiation exposure and healthcare costs. The ability to generate high-quality images from low-dose data can also expand access to PET scans, especially for vulnerable populations or for repeated follow-up scans.

Claim 1 — Plain English

What this patent covers

The patent describes a method for creating an AI system that can take blurry, low-dose Positron Emission Tomography (PET) images and make them clearer, similar to standard-dose PET images. It starts by building a "U-Net type picture generator" by connecting an "encoder" and a "decoder" using "skip connections" (Claim 1). Then, it creates multiple "generative adversarial networks" (GANs) by pairing these picture generators with "discriminators" (Claim 1). These GANs learn in parallel, sharing basic information, forming a "first multi-task learning-type generative adversarial network." The system is trained using a "joint loss function" that combines L1 type loss and cross entropy loss, comparing the AI's output to high-quality standard-dose PET images (Claims 1, 2). For example, if a patient receives a low-dose PET scan to reduce radiation exposure, this AI can process those images to produce diagnostic quality results.

The clever bit

The novelty lies in combining multiple "U-Net type picture generators" with "discriminators" into a "multi-task learning-type generative adversarial network," where these networks learn in parallel and share information. This parallel learning, guided by a specific "joint loss function" that considers both L1 and cross-entropy losses, allows the system to effectively reconstruct high-quality images from very low-dose PET data, leveraging additional MR image input.

What it does not cover

  • Does not cover methods for reconstructing PET images without using a "U-Net type picture generator" with "skip connections" (Claim 1).
  • Does not cover systems that use only a single generative adversarial network, as it specifies "a group of generative adversarial networks" and "plurality of picture generators" (Claim 1).
  • Does not cover methods where the "plurality of discriminators" do not use an "input modality," a "tag image," and an "output result" as input (Claim 1).
  • Does not cover methods that do not combine low-dose PET and MR images as input modalities for each GAN (Claim 1).
  • Does not cover training methods that do not use a "joint loss function 1" combining L1 type loss and cross entropy loss functions (Claim 1, 2).

Patent timeline

Filing

Application submitted to the patent office

Publication

Application published, typically 18 months after filing

Grant

Patent officially issued

Expiration

Patent enters public domain

PatentBrief Score

Impact Score

Early stage

Citation count

0/40

No citations yet

Claim breadth

7/20

Moderate scope

Recency

20/20

Granted within 5 years

Assignee scale

0/20

Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →

PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.

Heuristic Value Estimate

What this patent might be worth

Minimal

$29K – $92K

Midpoint $58K · 14.6 yr remaining · industry ×1.6

Adjust inputs →

Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.

Claim text not yet imported for this patent

The original legal language

Original claims

10 claims as filed with the patent office.

Concepts involved

ClaimPrior artNon-obviousnessNoveltySpecificationAssigneePatent term

Citations

Patent lineage

Cites earlier patents

8

earlier patents this invention cites as foundations

View prior art →

Cite this patent

Liu, X., Zhang, N., YANG, Y., Liang, D., Zheng, H., HU, Z., & Sun, H. (2023). AI Method for Sharpening Low-Dose PET Scans with Multi-Task Learning (U.S. Patent No. 11,756,161). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/11756161/method-and-system-for-generating-multi-task-learning-type-generative-adversarial

Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.

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Common Questions

Frequently Asked Questions

What does AI Method for Sharpening Low-Dose PET Scans with Multi-Task Learning cover?

This patent describes an AI method using a special type of neural network called a multi-task learning generative adversarial network (GAN) to improve the quality of medical images from low-dose PET scans, making them look like standard-dose scans.

Who owns patent US 11756161?

Shenzhen Institutes of Advanced Technology owns this patent, granted in 2023.

When does this patent expire?

This patent is expected to expire on June 7, 2041, when the invention enters the public domain.

What problem does this patent solve?

Positron Emission Tomography (PET) scans are crucial for diagnosing diseases like cancer, but they expose patients to radiation. This patent matters because it offers a way to get high-quality images from lower radiation doses, making PET scans safer and potentially more accessible. By improving image quality from low-dose data, it could lead to earlier and more accurate diagnoses with reduced patient risk.

What does this patent NOT cover?

Does not cover methods for reconstructing PET images without using a "U-Net type picture generator" with "skip connections" (Claim 1).

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Last reviewed: October 23, 2026 · PatentBrief is not a law firm and this is not legal advice.