Magnetic resonance examination method

Patent metadata

Field	Value
Publication number	US-12449495-B2
Application number	US-202218274773-A
Country	US
Kind code	B2
Filing date	Jan 24, 2022
Priority date	Feb 1, 2021
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A magnetic resonance examination method comprises acquisition of a set of magnetic resonance signals from magnetic spins in an object by way of a receiver antenna, the magnetic resonance signals' signal levels are related to an independent reference level that is independent of the receiver antenna's sensitivity to form a calibrated signal level of the magnetic resonance signals, the calibrated signal levels are recorded in terms of a relative density of ordered transverse spins (DOTS). The independent reference level may be derived from the signal-to-thermal-noise ratio. The calibrated signal level in terms of DOTS in μM/T reflects predominantly a tissue property (of (a voxel of) the patient to be examined) as well as details or characteristics of the acquisition sequence used.

First claim

The invention claimed is:

1. A magnetic resonance examination method comprising:
acquisition of a set of magnetic resonance signals from magnetic spins in an object by way of a receiver antenna,
relating the magnetic resonance signals' signal levels to an independent reference level that is independent of the receiver antenna's sensitivity to form one or more calibrated signal levels of the magnetic resonance signals; and
recording the calibrated signal levels in terms of a relative density of ordered transverse spins (DOTS).

2. The magnetic resonance examination method claim 1 , wherein two or more sets of the set of magnetic resonance signals from magnetic spins in an object are acquired by one or more respective receiver antenna (e),
the magnetic resonance signals' signal levels are related to the independent reference level that is independent of the receiver antenna's sensitivity to form one or more calibrated signal levels of the magnetic resonance signals,
the calibrated signal levels are recorded in terms of the relative density of ordered transverse spins (DOTS);
and the calibrated signals of the respective sets of magnetic resonance signals in terms of the relative density of ordered transverse spins (DOTS) are compared to each other.

3. The magnetic resonance examination method of claim 1 further comprising:
determining the independent reference level from a measurement of a signal-to-thermal-noise ratio of the receiver antenna; and
calibrating the measured signal-to-thermal-noise ratio in terms of the relative density of ordered transverse spins (DOTS) by relating the measured signal-to-thermal-noise ratio to a computed theoretical signal-to-thermal-noise ratio.

4. The magnetic resonance examination method of claim 3 further comprising:
accessing the receiver antenna's resonance quality factor; and
computing the computed theoretical signal-to-thermal-noise ratio from the receiver antenna's resonance quality factor.

5. The magnetic resonance examination method of claim 4 , further including:
determining the receiver antenna's resonant quality factor from the receiver antenna's resonance frequency response characteristic.

6. A magnetic resonance examination method including;
comparing respective sets of calibrated signals record in DOTS,
wherein said respective sets of calibrated signals originate from multiple acquisitions of sets magnetic resonance signals as claimed in claim 2 .

7. The magnetic resonance examination method of claim 1 , further comprising:
reconstructing a magnetic resonance image from the calibrated signals recorded in DOTS.

8. The magnetic resonance examination method of claim 1 , further comprising:
recording the object's temperature during acquisition of the magnetic resonance signals; and
taking the recorded temperature into account in the recording of the calibrated signal levels in terms of a relative density of ordered transverse spins.

9. A magnetic resonance examination system configured to perform the magnetic resonance examination method of claim 1 .

10. A computer program including instructions stored on a non-transitory computer readable medium for carrying-out the magnetic resonance examination method of claim 1 .

11. The magnetic resonance examination method of claim 1 , further including: reconstructing a magnetic resonance image from the acquired magnetic resonance signals and brightness values of the magnetic resonance image are expressed in DOTS.

12. The magnetic resonance examination method of claim 5 , wherein the receiver antenna's resonance frequency response characteristic is the frequency width of said response.

Assignees

• Koninklijke Philips Nv

Inventors

• Fuderer Miha
• Den Boer Jacques
• Van Liere Filips

Classifications

• G01R33/583

  Calibration of signal excitation or detection systems, e.g. for optimal RF excitation power or frequency (G01R33/246 takes precedence) · CPC title

• G01R33/5608 Primary

  Data processing and visualization specially adapted for MR, e.g. for feature analysis and pattern recognition on the basis of measured MR data, segmentation of measured MR data, edge contour detection on the basis of measured MR data, for enhancing measured MR data in terms of signal-to-noise ratio by means of noise filtering or apodization, for enhancing measured MR data in terms of resolution by means for deblurring, windowing, zero filling, or generation of gray-scaled images, colour-coded images or images displaying vectors instead of pixels (image data processing or generation, in general G06T) · CPC title

• G01R33/58 Primary

  Calibration of imaging systems, e.g. using test probes {, Phantoms; Calibration objects or fiducial markers such as active or passive RF coils surrounding an MR active material} · CPC title