Cooper & Dunham LLP
Magnetic resonance imaging apparatus
An MRI apparatus having an ability of displaying images of flow in different directions in distinguishable manner. When this MRI apparatus performs multi-slice acquisition with a predetermined repetition time TR by selecting a plurality of slices approximately perpendicular to the flow direction of an object to be examined, it performs a first measurement of exciting the plurality of slices in a first order and a second measurement of exciting the same slices in the opposite order to obtain two kinds of data whose signal intensity differs depending on the flow direction. The two kinds of data obtained by two measurements are subjected to subtraction operation to obtain data with different signs depending on the flow direction. These signs combined with the signal intensity are made into images where flow in opposite directions are distinctively depicted. In the multi-slice acquisition, slices are selected so that adjacent slices partially overlap in the direction of the thickness of the slice. Thereby signals of a static part can be suppressed and contrast of flow images after substraction can be enhanced. EPI method of very short imaging time can be employed for the imaging sequence of MRA according to the present invention.
Hitachi Medical Corporation
G A A G
G01R A61B A61B G01R
additional additional inventional inventional
Shigeru
Watanabe