A system (100) for medical imaging is disclosed. The system (100) includes: a computer tomography (CT) device (502) having a table (106); a memory (130) adapted to store: a computational model (211) including instructions; an updated measurement of blood flow speed at at least some of a plurality of specific locations (201) in a portion of the body, or at at least one other location in the portion of the body, or both; and an inferred blood flow speed throughout the portion of the body based on the computational model (211); and a processor. The instructions, when executed by the processor, cause the processor to: determine a contrast medium injection duration, and a speed of the table (106) prior to a CT scan (402) based on the inferred blood flow speed.