Ultrasound guidance in minimally invasive robotic procedures.

In the past decade, medical robotics has gained significant traction within the surgical field. While the introduction of fully autonomous robotic systems for surgical procedures still remains a challenge, robotic assisted interventions have become increasingly more interesting for the scientific and clinical community. This happens especially when difficulties associated with complex surgical manoeuvres under reduced field of view are involved, as encountered in minimally invasive surgeries. Various imaging modalities can be used to support these procedures, by re-creating a virtual, enhanced view of the intervention site. Among them, ultrasound imaging showed several advantages, such as cost effectiveness, non-invasiveness and real-time volumetric imaging. In this review we comprehensively report about the interventional applications where ultrasound imaging has been used to provide guidance for the intervention tools, allowing the surgeon to visualize intra-operatively the soft tissue configuration in real-time and to compensate for possible anatomical changes. Future directions are also discussed, in particular how the recent developments in 3D/4D ultrasound imaging and the introduction of advanced imaging capabilities (such as elastography) in commercially available systems may fulfil the unmet needs towards fully autonomous robotic interventions.