| 摘要 |
<p>PURPOSE:To take and display an angiographic image so as to display a concern region most clearly, by measuring the blood flow velocity of the concern region using an imaging sequence preliminarily measuring blood flow velocity quantitatively and subsequently controlling a spot having said velocity so as to have the max. density value on an image to perform imaging. CONSTITUTION:An image is taken by an imaging sequence and the blood flow velocity of a concern region is measured. In the sequency, phase turning is generated only with respect to the flow velocity in a Y-direction and the velocities in Z- and X- directions are not concerned. Therefore, the phase angle theta of rotation of a measuring signal is shown as theta=0.36gammaGy.tPtIVy on the basis of flow velocity Vy and, according to this formula, the flow velocity Vy of the concern region can be calculated. Since Vy is calculated, the parameter of the flow encoding pulse at the imaging time of a angiographic image is determined. The angiographic images are taken with respect to the sequences in a case applying the determined flow encoding pulse and in a case not applying said pulse. When subtraction is performed between two images of the concern region to calculate a difference image, the density concern region to calculate a difference image, the density value at said region becomes max. Therefore, the angiographic image sharply displaying the concern region can be taken.</p> |
