Turbo Spin Echo Artifact Reduction via Channel-Specific Phase Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Artifacts, specifically phantom-like stripes, occur in magnetic resonance image data due to signal differences and non-linearities in the gradient fields, particularly in turbo spin echo sequences, which can impair diagnostic accuracy.
Innovation Solution
A method involving loading measurement data and phase correction data from all channels, determining a step value for each channel to describe signal drops, and channel-by-channel manipulation of the measurement data to reduce or eliminate artifacts during image reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If turbo spin echo sequences are used to accelerate data acquisition, then productivity is improved, but artifacts appear in the image data due to signal differences and non-linear gradient fields
Solution Approach 1:
The patent applies preliminary action by performing phase correction measurements before the actual image acquisition. The system acquires phase correction data in a preliminary step, determines step values for each channel, and uses this information to correct the measurement data before reconstruction. This preliminary correction prevents artifacts from appearing in the final images while maintaining the fast acquisition speed of turbo spin echo sequences.
2Productivity
If multiple refocusing pulses are applied in TSE sequences, then productivity is improved by reducing measurement time, but signal differences between echoes cause artifacts
Solution Approach 1:
The patent applies local quality by determining individual step values for each channel based on their specific signal characteristics. Instead of applying a uniform correction across all channels, the system analyzes the signal drop in each channel separately and applies channel-specific correction factors. This localized approach maintains high image reconstruction accuracy while preserving the productivity benefits of multiple refocusing pulses.
Solution Approach 2:
The patent applies parameter changes by modifying the measurement data based on determined step values. The system changes the amplitude parameter of the measurement data for each channel individually, using the step values to scale the data appropriately. This parameter adjustment compensates for signal differences between echoes, preventing artifacts while maintaining the accelerated acquisition timeline.
3Object-affected harmful factors
If phase correction measurements are performed, then artifact reduction is achieved, but device complexity increases due to additional data processing steps
Solution Approach 1:
The patent applies segmentation by dividing the data processing into distinct segments: acquiring phase correction data, determining step values for each channel, manipulating measurement data based on step values, and reconstructing images. This segmented approach organizes the complex processing into manageable steps, making the system more controllable and easier to implement while effectively reducing phantom stripe artifacts.
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
The method significantly reduces or avoids artifacts in image data, thereby improving image quality and diagnostic accuracy by correctly localizing signal components and minimizing the impact of non-linear gradient fields.
Implementation Method 1
In order to induce nuclear spin resonances which can be measured as signals, radio-frequency excitation pulses (RF pulses) are irradiated into the examination object
Implementation Method 2
For spatial encoding of the measurement data, fast-switched magnetic gradient fields, called gradients for short, are overlaid on the basic magnetic field
Implementation Method 3
by irradiating at least one RF refocusing pulse after irradiation of the RF excitation pulse, the transversal magnetization is as it were 'turned', whereby the dephased magnetization is rephased again and thus what is known as a spin echo SE is generated
Data Source
AI summary
A method for avoiding artifacts in image data reconstructed from measurement data acquired by means of a TSE (turbo spin echo) sequence with a coil having a plurality of antenna elements associated with one channel respectively. The method includes loading the measurement data, acquired with the coil, of all channels of the coil; loading at least the first three echo signals respectively of an echo train from phase correction measurement data of all channels acquired with the coil in relation to the TSE sequence; determining a step value d for each channel of the coil from the loaded phase correction measurement data, which value describes a signal drop in the three successive echo signals of the phase correction measurement data; channel-by-channel manipulation of the measurement data as a function of the step value of the respective channel; and reconstructing image data by taking into account the manipulated measurement data.