Magnetic resonance imaging method; involves applying high frequency excitation pulse to test object in homogenous magnetic field and different magnetic field gradients

摘要

The method involves inserting a test object into a homogenous magnetic field. A magnetic field gradient, Gm, m=1, of given amplitude and orientation is applied. A high frequency excitation pulse is transmitted, which ends at time tm, m=1. The signal produced from the excitation pulse is detected over at least a given time T. This signal is scanned with a scanning rate DELTA f, so that more than one signal values are registered for each excitation, of which the first is detected at a given waiting time tau of at least tm + tau . The steps are repeated for a given number, M-1, of magnetic field gradients, Gm, m =2-M. For at least one of the M steps, preferably the m'th step, the first signal to time tm' + tau is detected. The maximum signal band with DELTA fS of the test object for all the magnetic field gradients is adjusted so that tau DELTA fS is less than 1. The scanning rate, DELTA fS, is chosen to be greater than or equal to DELTA fS, so that reconstruction errors through erroneous contributions of unmeasured signal values in the time period of the excitation pulse and of the waiting time tau for each successive excitation pulse are reduced.