Site-Selective Inversion Pulse for MRI Artifact Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic resonance imaging (MRI) techniques face challenges in effectively preparing nuclear spins and suppressing interference signals from outside the examination area, leading to image artifacts and reduced signal quality due to the overlap of inversion pulse ranges with the area of interest.
Innovation Solution
A method involving the use of site-selectively applied inversion pulses, positioned at least partially outside the examination area, to prepare nuclear spins and suppress interference signals, thereby improving image quality by minimizing the influence on the area of interest and reducing contamination from external tissue signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inversion pulses are applied to prepare nuclear spins in the examination area, then signal preparation is improved, but interference signals from outside the examination area cannot be suppressed
Solution Approach 1:
The patent applies different properties to different spatial regions by using site-selective inversion pulses that act only on specific regions outside the examination area, while leaving the examination area unaffected. This creates local preparation zones with distinct magnetic properties that suppress external interference without impacting the region of interest.
Solution Approach 2:
The patent divides the spatial domain into separate regions: the examination area and external regions. By applying inversion pulses selectively to external regions only, the method segments the preparation process from the imaging process, allowing independent optimization of signal suppression without compromising image quality.
2Reliability
If inversion pulse range overlaps with the area under examination, then nuclear spin preparation is enhanced, but image artifacts increase due to contamination from external tissue signals
Solution Approach 1:
The patent extracts the spin preparation function from the examination area and relocates it to external regions. By applying inversion pulses only outside the examination area, the method separates the preparation process from the imaging process, eliminating the source of artifacts while maintaining preparation effectiveness.
3Object-affected harmful factors
If site-selective inversion pulses are applied outside the examination area, then external interference is suppressed, but the complexity of pulse sequencing increases
Solution Approach 1:
The patent performs spin preparation in advance, before the actual imaging sequence begins. By applying inversion pulses to external regions prior to excitation pulses, the method prepares the magnetic state of external tissues ahead of time, allowing them to decay naturally and preventing their signals from contaminating the final image.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the signal-to-noise ratio and image quality by selectively preparing nuclear spins and suppressing external interference, allowing for more accurate evaluation of MRI data without artifacts.
Implementation Method 1
the nuclear spins of specific atoms resonantly excited by these radio-frequency pulses to be tilted by a defined flip angle with respect to the magnetic field lines of the basic magnetic field
Implementation Method 2
the body to be examined of a person under examination, in particular a patient, is conventionally exposed to a relatively high basic magnetic field, for example of 1.5 or 3 or 7 tesla
Implementation Method 3
Radio-frequency pulses, for example excitation pulses, are then emitted by a radio-frequency antenna unit by the operation of suitable antenna systems
Implementation Method 4
gradient switchings are produced by the operation of gradient coil unit
Data Source
AI summary
In a method and apparatus for acquiring magnetic resonance image data, improved preparation of nuclear spins is achieved by radiating at least one inversion pulse, which acts site-selectively on at least one inversion pulse range, with the at least one inversion pulse range being situated at least partially outside the area under examination, radiation of at least one excitation pulse, read-out of magnetic resonance signals from the area under examination, and reconstruction of magnetic resonance image data from the read-out magnetic resonance signals, the magnetic resonance image data depicting the area under examination.