3D Spoiled Gradient Recalled MRI Using Interleaved-Randomized Spoilers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The inefficiency of spoiled gradient-recalled (SPGR) sequences in MRI due to time-consuming gradient spoiling, which can introduce severe image artifacts when spoiling gradients are removed.
Innovation Solution
Implementing an interleaved-randomized spoiler (IRS) gradient in the 3D-cones sequence, which randomizes the spoiler gradient amplitude and applies it after every M-th acquisition block, effectively reducing image artifacts while shortening acquisition time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If spoiling gradients are applied in conventional SPGR sequences, then image artifacts from unspoiled transverse magnetization are reduced, but acquisition time increases significantly
Solution Approach 1:
The patent applies spoiling gradients periodically rather than continuously - specifically after every M-th acquisition block where M≥2. This periodic application maintains sufficient spoiling to prevent image artifacts while reducing the overall time spent applying gradients, thereby decreasing acquisition time by approximately 20% compared to conventional continuous spoiling.
Solution Approach 2:
The patent introduces dynamic randomization of the spoiler gradient area, where the absolute area is randomized between zero and a maximum value for each spoiler application. This dynamic variation prevents coherent artifacts from unspoiled magnetization while allowing flexible time management, achieving both artifact reduction and time efficiency.
2Productivity
If spoiling gradients are removed to reduce acquisition time, then scan efficiency improves, but severe image artifacts arise from unspoiled transverse magnetization
Solution Approach 1:
The patent applies partial spoiling rather than complete continuous spoiling - using spoilers after every M-th acquisition block instead of after every block. This partial action is sufficient to prevent severe artifacts while leaving out unnecessary spoiler applications, thereby improving scan efficiency and reducing acquisition time by approximately 20%.
Solution Approach 2:
The patent changes the parameter of spoiler gradient area from a fixed value to a randomized value between zero and maximum for each application. This parameter randomization allows the system to achieve effective spoiling when needed while minimizing gradient application time, thus improving productivity without sacrificing image quality.
3Reliability
If conventional spoiling gradients are used in 3D-cones sequence, then transverse magnetization is spoiled, but the spoiler consumes up to 40% of the time to repetition (TR)
Solution Approach 1:
The patent implements periodic spoiling by applying the spoiler gradient after every M-th acquisition block rather than after every TR. This reduces the frequency of spoiler application from 100% to approximately 20-50% depending on M, directly reducing the time consumed by spoilers from up to 40% of TR to approximately 20% or less, while maintaining sufficient spoiling effectiveness.
Solution Approach 2:
The patent introduces dynamic randomization of spoiler gradient area, allowing the system to adapt the spoiling strength on a per-application basis. This dynamic approach ensures reliable magnetization spoiling when applied while minimizing the time penalty, achieving both reliability and time efficiency.
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 IRS technique achieves a 20% reduction in acquisition time without introducing image artifacts, maintaining similar image quality to fully spoiled sequences, and can be applied to various MRI scanners and trajectories.
Implementation Method 1
The SPGR sequence relies on randomized RF phase and spoiling gradient (usually referred to as a spoiler) after the readout gradient to destroy the residual magnetization that can cause severe image artifacts
Implementation Method 2
magnetic resonance imaging (MRI)
Data Source
AI summary
A method for magnetic resonance imaging (MRI) performs a spoiled gradient-recalled (SPGR) MRI scan with an MRI scanner to produce MRI data; and reconstructs an MRI image from the MRI data; wherein performing the SPGR MRI scan comprises playing an interleaved-randomized spoiler (IRS) gradient after every M-th acquisition block, where M≥2, and where an absolute area of the IRS gradient of each IRS is randomized between zero and a maximum gradient area achievable on the MRI scanner.