Intelligent automatic registration: is it feasible and efficient for application of ultrasound fusion imaging in liver?

Purpose: To evaluate the feasibility and efficiency between the two intelligent auto-registrations (based on hepatic vessels or based on liver surface) and manual registration for US-CT/MR fusion imaging of liver tumours.

Methods: From May 2017 to December 2017, 30 patients with 30 liver tumours were enrolled in this prospectively study. Two intelligent auto-registrations (based on hepatic vessels or based on liver surface) and manual registration were randomly performed, the registration success rate and efficiency were compared.

Results: In terms of success rate, auto-registrations based on the hepatic vessels (80%) was lower than auto-registration base on liver surface and manual registration (96.67%), but with no statistical difference (P = 0.125). In comparison of the registration efficiency, the efficiency of the auto-registration based on the hepatic vessels was superior to auto-registration based on liver surface and manual registration (P < 0.05). The one-step success rate of auto-registration based on the hepatic vessels (53.33%, 16/30) was higher than that of other two registrations (P < 0.05). Stratified analysis showed that, for the lesion with display of hepatic vessels in grade 3, the success rate of auto-registration based on vessels (0%) was lower than that of auto-registration based on liver surface and manual registration (100%) (P = 0.031).

Conclusion: Intelligent auto-registration based on hepatic vessels is a feasible and efficient registration method for US-CT/MR fusion imaging of liver tumours for the patients with clear hepatic vessels. The auto-registration based on liver surface and manual registration can be an effective supplement for cases with poor hepatic vessels display.