| 摘要 |
PROBLEM TO BE SOLVED: To improve position and/or time resolution of measurement by deciding the time order so as to catch the central segments more frequently than the outside segments in k-shape for different combination of phase coding. SOLUTION: The areas of segments A, B and C are all equal. The measurement order corresponding to individual segment is that the data for the center are measured with a frequency double the data for outside segment B and C. The symmetry of k-shape division better fits the object to be taken in the ring-form segmentation. For instance, when the object is a blood vessel with a longitudinal direction along the read-out gradient, the cross-section of the blood vessel positions within both phase coding gradient planes. The cross-section of the blood vessel is described by a circular plane for the first approximation, and segmentation of the ring-form k-shape enables diffused state of diffused medium and practice of 3D measurement. Thus, an optimum relation of time and position resolution is obtained.
|
