Determining linear phase shift in conjugate domain for MR imaging

A method for constructing an MR image of an object comprising the steps of:

• applying a multi-echo MR image sequence to said object to acquire a set of complex valued MR data samples in the time domain, said acquired data samples having an associated time shift, said time shift corresponding to a linear phase shift in the domain conjugate to that of the acquired data;
• generating a set of conjugate data samples in said conjugate domain from said acquired data samples:
• determining said linear phase shift by convolving adjacent conjugate data samples to provide a specified function, and computing the value of said function at a specified spectral frequency to determine said linear phase shift;
• and
• employing said linear phase shift to reduce artifacts in constructing an MR image of said object.

Apparatus for constructing an MR image of an object comprising:

• a set of MR components operable to acquire a set of complex valued MR data samples in a specified domain, said acquired data samples being associated with said object and having an associated linear phase shift;
• a processor operable to generate a set of conjugate data samples in a domain which is conjugate to said specified domain from said acquired data samples, and to determine said linear phase shift of said acquired data samples by convolving adjacent conjugate data samples to provide a specified function, and to compute the value of said function at a specified spectral frequency;
• and
• said processor is further operable to construct an MR image of said object, and to employ said linear phase shift to reduce artifacts in said image construction.