Segmented MRI Shim Tray for Rated-Field Shimming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional shimming processes for magnetic resonance imaging (MRI) apparatuses require repeated demagnetization and excitation of the static magnetic field magnet, consuming helium and increasing work hours due to the large magnetic forces involved in inserting and removing shim trays at rated magnetic fields, posing safety hazards.
Innovation Solution
The MRI apparatus is equipped with shim trays divided into multiple shim tray element parts, allowing safe insertion and removal during shimming operations even at rated magnetic fields by reducing the magnetic force on each part, thereby minimizing helium consumption and work hours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If shim trays are inserted and removed at rated magnetic field during shimming operations, then shimming efficiency is improved, but large magnetic forces pose safety hazards and increase work hours
Solution Approach 1:
The shim tray is divided into multiple detachable elements that can be independently inserted and removed. This segmentation reduces the magnetic force on each individual element, making handling safe while maintaining shimming efficiency. The patent specifically describes a shim tray composed of multiple shim tray elements that can be separately manipulated during shimming operations.
2Manufacturing precision
If repeated demagnetization and excitation of the static magnetic field magnet is performed, then magnetic field uniformity is improved, but helium consumption increases and work hours increase
Solution Approach 1:
The shim tray elements are pre-positioned and prepared outside the magnet gantry before insertion. This preliminary arrangement allows the magnetic field to remain excited without repeated demagnetization cycles, reducing helium consumption while achieving the required magnetic field uniformity through optimized element placement.
Solution Approach 2:
By dividing the shim tray into multiple elements, the system achieves magnetic field uniformity through incremental adjustments rather than repeated full demagnetization and excitation cycles. This segmentation allows finer control over the shimming process, reducing the need for multiple complete magnet cycles and thereby conserving helium.
3Manufacturing precision
If the static magnetic field magnet is frequently demagnetized and excited during shimming, then magnetic field uniformity is improved, but operational time increases
Solution Approach 1:
The divided shim tray elements enable more efficient shimming operations by allowing targeted adjustments without requiring frequent complete demagnetization and excitation cycles. This reduces the number of iterative cycles needed to achieve magnetic field uniformity, thereby decreasing work hours.
Solution Approach 2:
Shim tray elements are prepared and positioned in advance outside the magnet gantry, allowing the magnetic field to remain excited throughout the shimming process. This preliminary preparation eliminates repeated demagnetization and excitation cycles, significantly reducing operational time while maintaining magnetic field uniformity.
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 design ensures safer and more efficient shimming operations by reducing the frequency of demagnetizing the static magnetic field magnet, thus conserving helium and decreasing operational time.
Implementation Method 1
a magnet configured to generate a static magnetic field in a bore in which a subject is positioned
Implementation Method 2
Each of the first shim tray element part and the second shim tray element part is inserted into and removed from the magnet gantry... by reducing the magnetic force on each part
Implementation Method 3
The demagnetization and excitation of the static magnetic field magnet in the shimming operations consume helium for cooling the static magnetic field magnet
Data Source
AI summary
A magnetic resonance imaging apparatus according to an exemplary embodiment includes a magnet gantry including a magnet configured to generate a static magnetic field in a bore and a shim tray including a first shim tray element part and a second shim tray element part, the first shim tray element part including a first shim pocket in which a magnetic shim which is configured to adjust the static magnetic field is stored, and the second shim tray element part including a second shim pocket in which the magnetic shim is stored. Each of the first shim tray element part and the second shim tray element part is inserted into and removed from the magnet gantry along an axial direction of the bore through at least one of openings provided on one end side of the magnet gantry and the other end side of the magnet gantry in the axial direction.