Purpose: To evaluate whether a single-breath hold and single-level test bolus-injection dynamic scanning (SLTBDS) was a good way of defining the portal contrast media peak time and its preliminary application with spiral CT portography (SCTP).

Then taking the influ- ence of metal forming temperature and velocity on flow stress into account, the formulation of contact stress in the groove of extrusion wheel is deduced by means of the successive element method, which provide theoretical basis for the continuous extrusion equipment.