(The) multiple position tagging MR angiography

Abstract

As an improved subtractive angiography technique using the time-of-flight effects, the multiple position tagging method is proposed to get the extended field of view and to be independent of the cardiac gating with keeping the merits of the existed time-of-flight angiography. It is possible to image even constant flow by the multiple tagging method. Multiple images corresponding to each different tagging position are obtained by using SSFP technique and Fourier analysis is performed along each shifted tagging position images. The angiogram is constructed by the summation of a few images of lower harmonic components excluding the DC component from the Fourier analysed images. To determine the optimal conditions of RF pulses, numerical simulation is performed and its results are adopted to the experiments. Several phantom studies show good agreements with the simulation. The images corresponding to each tagging and reading RF pulses are compared, as well.