| 摘要 |
<p>PURPOSE:To recognize the flow speed direction of blood for imaging from an exciting part and its position relationship, by selectively exciting the desired slicing part of a body to be checked and then the slicing part along the running direction of a blood vessel for imaging. CONSTITUTION:A magnetic field Gz having a slanted Z axis (or a magnetic field Gy having a slanted Y axis) are applied as a slanted magnetic field for slicing. A 90 deg. RF pulse is applied. Thus, a slicing plane S1 (or S2) is excited. Therefore, the magnetic field Gz is applied in order to encode the collection of signals at the plane S2. A 180 deg.C RF pulse is applied. The magnetic fields Gy and Gx are applied by an ordinary encode method and a lead slanted- magnetic-field applying method. Echo signals caused by magnetic resonance are generated. The signals are detected with a probe 4 and processed in a CPU 13. The tomography data at the plane S2 is obtained and the image is displayed. The blood in blood vessels BV1 and BV2, which are excited at the plane S1 are moved by distances d1 and d2 from the plane S1 on the plane S2 owing to the blood flow speeds. Thus the low signal levels are obtained. Since a slice thickness (h) of the plane S1 and the like can be found, the blood flow speeds V1 and V2 can be obtained by specified expressions.</p> |
