| 摘要 |
<p>An X-ray computed tomograph for forming a sharp reconstructed image of a heart and a coronary artery. The diastolic phase between R-waves of an electrocardiogram is divided into a rapid inflow period, a slow inflow period, and atrial systole period. The rapid inflow period is a period during which blood rapidly flows in a ventricle, the heart moves, and collection of projection data is not suited. The slow inflow period is a period during which the movement of the heart is most quite and collection of projection data is suited. The atrial systole period is a period during which the ventricle moves when the atria contracts, and collection of projection data is hardly influenced. When a projection data collection window of the X-ray computed tomograph is 250 ms, and when the heart beat rate is less than 65/minute, the final stage of the data collection window is set at or around the peak of the P-wave. When the heart beat rate is more than 65/minute, the final stage of the 1/2 data collection window is set at or around the peak of the R-wave. Thus a two-phase system is used.</p> |
