TIMING ALGORITHM FOR BOLUS CHASE MR DIGITAL SUBTRACTION ANGIOGRAPHY

To acquire multiple longitudinal locations in the lower extremity afte r a single contrast injection, appropriate table translation and contr ast injection are required. An approximate model based on constant bol us velocity was developed to describe the space-time course of a contr ast bolus in the lower extremity. This model was verified in dynamic M R angiograms acquired in a group of patients using time-resolved 2D MR digital subtraction angiography (MRDSA), From this contrast bolus pas sage model, a timing algorithm for table translation and contrast inje ction was developed for bolus chase MRDSA, subsequently validated in b olus chase 2D MRDSA experiments. All targeted major peripheral arterie s were well depicted in bolus chase 2D MRDSA using this timing algorit hm and a single 15-ml contrast dose.