Wave-Encoded MRI Auto-Calibration Reducing Scan Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional wave-encoded MRI techniques require separate calibration scans, result in increased complexity and time, and often produce image artifacts due to distortion and blurring, with challenges in motion correction and RF coil sensitivity mapping.
Innovation Solution
A method and system for wave-encoded MRI that applies wave-encoded magnetic gradients, calibrates the wave point-spread function based on intermediate images, and reconstructs images without the need for prephasers, rephasers, or external calibrations, using self-refocusing gradients and data-driven coil sensitivity mapping, and incorporates motion correction and parallel imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional wave-encoded MR acquisition techniques use separate calibration scans to estimate wave PSF, then measurement precision is improved, but loss of time and device complexity increase
Solution Approach 1:
The patent combines the wave PSF estimation process with the main imaging acquisition by using auto-calibrated wave-CAIPI reconstruction that estimates wave PSF from the imaging data itself, eliminating the need for separate calibration scans. This merging of calibration and imaging processes directly reduces total scan time while maintaining measurement precision.
Solution Approach 2:
The system performs self-calibration by using the imaging data to automatically estimate the wave PSF through CAPIRINHA-type uniform under-sampling. The calibration process serves itself by extracting necessary information from the acquired imaging data without requiring external calibration scans or additional hardware.
2Measurement precision
If traditional wave-encoded MR acquisition techniques use separate calibration scans for RF coil sensitivity maps, then measurement precision is improved, but device complexity and loss of time increase
Solution Approach 1:
The patent merges RF coil sensitivity map estimation with the main imaging acquisition by deriving sensitivity information from the auto-calibrated wave-CAIPI reconstruction. This eliminates the need for separate calibration scans and reduces acquisition sequence complexity while maintaining measurement precision.
Solution Approach 2:
The imaging acquisition serves multiple functions simultaneously: it acquires diagnostic imaging data, estimates wave PSF, and determines RF coil sensitivity maps. This multi-functionality reduces both time and complexity by eliminating dedicated calibration sequences.
3Measurement precision
If prephasers and rephasers are used to refocus MR signal to central k-space, then measurement precision is improved, but loss of time and device complexity increase
Solution Approach 1:
The patent extracts and removes the need for prephasers and rephasers by using wave gradients that are inherently self-refocusing. The wave gradient design directly refocuses the MR signal to central k-space without requiring additional gradient pulses, thereby reducing gradient waveform complexity and scan time.
Solution Approach 2:
The wave gradients are designed to be self-refocusing, meaning they automatically refocus the MR signal to central k-space through their inherent waveform structure. This self-service capability eliminates the need for external prephaser and rephaser components, reducing system complexity.
4Manufacturing precision
If wave gradients are applied during readout of each k-space line, then manufacturing precision of image quality is improved, but loss of time increases due to additional calibration requirements
Solution Approach 1:
The patent combines wave gradient application with auto-calibrated reconstruction to achieve high-quality images without separate calibration scans. The wave gradients spread aliasing in all spatial directions while the auto-calibration process simultaneously estimates wave PSF from the acquired data, maintaining image quality while reducing time.
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 reduces scan time, minimizes artifacts, and improves coil sensitivity accuracy, enabling highly accelerated and motion-robust wave-encoded MRI with efficient use of RF coil sensitivities and reduced workflow impact.
Implementation Method 1
MRI is a widely accepted and commercially available technique for obtaining digitized visual images representing the internal structure of objects having substantial populations of atomic nuclei that are susceptible to nuclear magnetic resonance (NMR)
Implementation Method 2
Wave-encoded MRI is a form of MRI in which oscillating magnetic gradients are applied during the readout of each k-space line on the phase and slice-encoding axes
Data Source
AI summary
A method for performing wave-encoded magnetic resonance imaging of an object is provided. The method includes applying one or more wave-encoded magnetic gradients to the object, and acquiring MR signals from the object. The method further includes calibrating a wave point-spread function, and reconstructing an image from the MR signals based at least in part on the calibrated wave point-spread function. Calibration of the wave point-spread function is based at least in part on one or more intermediate images generated from the MR signals.