Rapid angular measurement using MAMBA

A simple coil device can be configured to give an accurate measurement of the angle between the axis of the coil and B0 which is approximately linear over a wide angular range. An oblique plane was accurately selected to within 2-3 degrees using the angular information from the MAMBA probe. As an alternative to use of a dedicated receiver coil, shift of the frequency signal to the noise region at edge of the spectral bandwidth could be used to separate the angular measurement signal from the main image data, assuming sufficient dynamic range. The lack of translational information may be a problem in certain applications, but the method is capable of very rapid angular determination in a single FID without the use of switched field gradients. The ‘MR proctractor’ may be useful for rapidly determining alignment of limbs for Magic Angle imaging studies and multiple coils could be used when several articulations need to be measured simultaneously.