METHOD AND APPARATUS FOR AUTOMATIC DETECTION OF COIL POSITION USING GRADIENT ENCODING AND A 3-AXIS MAGNETIC SENSOR
Publication Date: 2017-May-10
The IP.com Prior Art Database
A method for automatically detecting coil position in a MR system uses a gradient field, which already exists in every MR system, as anchors. A three-axis magnetic sensor (e.g. Hall sensor) is added onto the coil for the positioning purpose. This gradient field of the MR system is used to determine magnetic field strength, which allows for calculation of the position of the sensor, and thereby the location of the coil.
The present disclosure relates generally to magnetic resonance (MR) imaging systems, and more particularly to automatic coil position detection in MR systems.
Currently available MR systems require an operator to input the coil position, for example, using Touch and Go protocols, and the position accuracy is dependent on the accuracy and skill levels of the operator. The manual procedure is therefore unreliable, and it is desirable to automate the coil position detection. Attempts at automating coil position detection include scan-based and anchor-based solutions, however, conventional solutions suffer with disadvantages.
For example, in the scan-based solutions, an extra scan (e.g. ALAC or a Calibration scan) is performed, and signals received from both the body coil and the floating coil is collected. The floating coil image is registered with the body coil image to detect the position of the coil. However, such techniques require additional scans, which prolongs the scanning time. In the anchor-based solutions, physical anchor point(s) (e.g. top bar of the MR table) is/are provided and the sensors detect the distance between the coil and the anchor point(s), in order to calculate the position of the coil. However, devices for measuring distance in strong magnetic fields are generally expensive, and raise the cost of the MR system significantly.
Therefore, there is a need for techniques and devices to detect the position of the coil automatically.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts a schematic illustrating the detection of the hall sensor positioning in a MR image system.
This present disclosure employs a novel anchor-based method, which uses gradient encoding as the positioning media, and a 3-axis magnetic sensor (e.g. a Hall sensor) to read the magnetic field strength of 3 axes of its current position. The gradient coil is mov...