G - Physics – 01 – N
Patent
G - Physics
01
N
324/1
G01N 24/08 (2006.01) A61B 5/05 (2006.01) G01R 33/54 (2006.01) G01R 33/56 (2006.01) G01R 33/483 (2006.01)
Patent
CA 1186376
A B S T R A C T: In NMR tomography, the nuclear spins of a selected type present in a selected area of a body are selectively excited by applying first a selection gradient field and exciting thereafter the nuclear spins by a HF signal which initially effects a rotation of the nuclear spins situated in a selected plane by an angle .alpha. of less than 90°, then a rotation of all selected nuclear spins by 90° and finally again a rotation of the nuclear spins contained in the selected plane by an angle of 90° - .alpha.. As a result thereof, the nuclear spins contained in the selected area have resumed at the end of this excitation their original orientation determined by a homogeneous magnetic field, while nuclear spins located outside this area lie within a plane extending almost vertically thereto. Thereafter, a measuring gradient field may be switched on without disturbing the orientation of the nuclear spins contained in the selected area. With the measuring gradient field switched on, the nuclear spins are now excited by a 90° pulse or usual pulse sequences to produce an induction signal. The measuring processes are carried out in pairs, with the selection gradient field applied, using different excitation signals so that the nuclear spins contained in the selected area are alternately oppositely directed which means that the induction signals generated by them are phase-shifted by 180°, whereas the nuclear spins - 2 - situated outside the selected area are shifted in the same sense, so that they supply identical signals, if any. By subtracting the induction signals gained in two successive measurements, the signals supplied by the nuclear spins situated outside the selected area are eliminated, whereas the signals supplied by the nuclear spins situated in the selected area are opposite in phase and, therefore, added up.
423382
Post Hans
Ratzel Dieter
Bruker Medizintechnik Gmbh
Gowling Lafleur Henderson Llp
LandOfFree
Method for measuring the nuclear magnetic resonance for nmr... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for measuring the nuclear magnetic resonance for nmr..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for measuring the nuclear magnetic resonance for nmr... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1179769