Pennie & Edmonds LLP
Method and apparatus for producing magnetic resonance angiogram
 According to the present invention, during performing an MRA sequence comprising a plurality (N) of pulse sequence units each of which gives blood flow a different phase rotation, one sequence unit is repeated a given number (L) of times in every cardiac cycle gated by ECG or pulse wave signals of the object under examination. A measurement of N cardiac cycles, as one round, is repeated to collect data completely filling a k-space for each sequence unit. In this repetition, the order of phase encoding magnetic fields is controlled so that data in the low frequency region of k-space are acquired at the cardiac phase corresponding to the diastolic phase of one cardiac cycle and data in the high frequency region are acquired at the cardiac phase corresponding to the systolic phase. The MRA of the present invention is not likely to be affected by the changes in blood flow caused by heart beats and does not prolong the time for measurement. 
Hitachi Medical Corporation
G G
G01R G01R
inventional additional
Shigeru
Watanabe