ROTATABLE RF COIL FOR MAPPING OF ORIENTATION-DEPENDENT QUANTITIES
Publication Date: 2016-Aug-22
The IP.com Prior Art Database
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Sketch of coil rotation in the two directions perpendicular to B0.
The development relates to a magnetic resonance imaging method notably for quantitative susceptibility measurements (QSM). The computation of the local susceptibility from the local spatial magnetic field variations involves a deconvolution by a dipole operator that has zeroes on a cone surface. Accordingly the deconvolution is often highly ill-posed.
A patient (head) carrier is provided that can rotate the patient's head in a controlled fashion, i.e. to move the patient' head between different orientations relative to the main magnetic field.. The rotation should be around an axis transverse to the main magnetic field direction. Magnetic resonance signals are acquired for several positions of the patient (head) so that sufficient amount of data are acquired (e.g. using the QBC) to lift the ill-posedness of the deconvolution.
In one embodiment the patient (head) carrier is integrated with a (birdcage) head coil that is then displaced together with the patient's head.
In a further aspect, the main magnetic field is orientated in different directions and measurements are made at the respective directions. This aspect may be applied in a table-top MRI device (e.g. for wrist imaging) by rotating the (small) main magnet into different orientations.
The inverse problem of Quantitative Susceptibility Mapping QSM is ill-posed within a certain region of the k- space, where the dipole reconstru...