(71) analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems. Ultimately, the system models become the (72) for designing and constructing an improved system. (73) is such a technique. The emphasis in this technique is process-centered. Systems analysts draw a series of process models called (74) . (75) is another such technique that integrates data and process concerns into constructs called objects.

A．image
B．picture
C．layout
D．blueprint

影响DSA影像质量的因素不包括（）

A.设备因素

B.成像方式

C.操作技术

D.造影方法

E.患者心理因素