T2-WEIGHTED MR IMAGING WITH ELIMINATION OF NON-T2-WEIGHTED SIGNAL CONTIBUTIONS

摘要

The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (1). It is an object of the invention to enable T₂-weighted MR imaging which is essentially free from interfering contributions from MR signals without T₂ weighting. The method of the invention comprises the steps of: a) subjecting the object (10) to a first T₂ preparation sequence (T2PREP1) comprising an excitation RF pulse (21), one or more refocusing RF pulses (22), and a tip-up RF pulse (23); b) subjecting the object (10) to a first readout sequence (RO1) comprising at least one excitation RF pulse and switched magnetic field gradients for acquiring a first set of MR signals; c) subjecting the object (10) to a second T₂ preparation sequence (T2-PREP2) comprising an excitation RF pulse (21′), one or more refocusing RF pulses (22′), and a tip-up RF pulse (23′), wherein at least one of the RF pulses (21′, 22′, 23′) of the second T₂ preparation sequence (T2PREP2) has a different phase than the corresponding RF pulse (21, 22, 23) of the first T₂ preparation sequence (T2PREP1); d) subjecting the object (10) to a second readout sequence (RO2) comprising at least one excitation RF pulse and switched magnetic field gradients for acquiring a second set of MR signals; e) reconstructing a MR image from the first and second sets of MR signals. Moreover, the invention relates to a MR device and to a computer program for a MR device.