Patents on Quantitative Susceptibility Mapping (QSM) of Tissue Magnetism

Recent Pat Biotechnol. 2019;13(2):90-113. doi: 10.2174/1872208313666181217112745.

Abstract

Background: Quantitative susceptibility mapping (QSM) depicts biodistributions of tissue magnetic susceptibility sources, including endogenous iron and calcifications, as well as exogenous paramagnetic contrast agents and probes. When comparing QSM with simple susceptibility weighted MRI, QSM eliminates blooming artifacts and shows reproducible tissue susceptibility maps independent of field strength and scanner manufacturer over a broad range of image acquisition parameters. For patient care, QSM promises to inform diagnosis, guide surgery, gauge medication, and monitor drug delivery. The Bayesian framework using MRI phase data and structural prior knowledge has made QSM sufficiently robust and accurate for routine clinical practice.

Objective: To address the lack of a summary of US patents that is valuable for QSM product development and dissemination into the MRI community.

Method: We searched the USPTO Full-Text and Image Database for patents relevant to QSM technology innovation. We analyzed the claims of each patent to characterize the main invented method and we investigated data on clinical utility.

Results: We identified 17 QSM patents; 13 were implemented clinically, covering various aspects of QSM technology, including the Bayesian framework, background field removal, numerical optimization solver, zero filling, and zero-TE phase.

Conclusion: Our patent search identified patents that enable QSM technology for imaging the brain and other tissues. QSM can be applied to study a wide range of diseases including neurological diseases, liver iron disorders, tissue ischemia, and osteoporosis. MRI manufacturers can develop QSM products for more seamless integration into existing MRI scanners to improve medical care.

Keywords: Bayesian framework; MRI; Quantitative susceptibility mapping; biodistribution; magnetic susceptibility; tissue magnetism..

Publication types

  • Review

MeSH terms

  • Bayes Theorem
  • Bone and Bones / diagnostic imaging*
  • Bone and Bones / metabolism
  • Bone and Bones / pathology
  • Brain / diagnostic imaging*
  • Brain / metabolism
  • Brain / pathology
  • Brain Neoplasms / diagnostic imaging
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Contrast Media / chemistry
  • Contrast Media / pharmacokinetics*
  • Humans
  • Iron / chemistry
  • Iron / metabolism
  • Iron Overload / diagnostic imaging
  • Iron Overload / metabolism
  • Iron Overload / pathology
  • Ischemia / diagnostic imaging
  • Ischemia / metabolism
  • Ischemia / pathology
  • Liver / diagnostic imaging*
  • Liver / metabolism
  • Liver / pathology
  • Magnetic Phenomena
  • Magnetic Resonance Imaging / instrumentation
  • Magnetic Resonance Imaging / methods*
  • Molecular Probes / chemistry
  • Molecular Probes / pharmacokinetics*
  • Nervous System Diseases / diagnostic imaging
  • Nervous System Diseases / metabolism
  • Nervous System Diseases / pathology
  • Osteoporosis / diagnostic imaging
  • Osteoporosis / metabolism
  • Osteoporosis / pathology
  • Patents as Topic
  • Tissue Distribution

Substances

  • Contrast Media
  • Molecular Probes
  • Iron