Portal Venous Phase Images. A greater fraction of portal venous phase scans obtained with patient-tailored scan delay were judged to be optimal (63 of 73 [86%]) compared with those obtained with a fixed scan delay of 80 seconds (51 of 73 [70%], p < 0.05). Nine (12.3%) patient-tailored scans were early, and one (1.4%) was very early, compared ....