Sixty-four-multidetector-row computed tomography angiography with bolus tracking to time arterial-phase imaging in healthy liver: is there a correlation between quantitative and qualitative scores?

Purpose: To determine the optimal 64-multidetector-row computed tomography scan delay from bolus-tracking trigger for the arterial phase and the evaluation of vascularization in healthy liver. Materials and Methods: One hundred twenty patients are randomized into 3 groups according to scan delay (5-, 10-, 15-second arterial phase) and underwent CT of the liver. Images were evaluated on the basis of quantitative and qualitative scores. A correlation analysis between them was managed to find the most effective scan delay for best radiologists' diagnostically performances. Results: Scanning too early results in images that are acquired before the vascular peak enhancement while scanning to late results in the increasing of liver parenchyma portal feeding. Good performances were obtained with a scan delay ranging between 10 and 19 seconds from the trigger. Conclusions: When a 64-multidetector-row computed tomography with a bolus-tracking program is used, only 1 arterial phase should be acquired, setting a scan delay of 10 to 19 seconds.