Robot-Assisted Medical Imaging: A Review

Robot-assisted medical imaging entails the use of a robot to acquire a medical image. Examples include robot-assisted endoscopic camera imaging, ultrasound imaging where the transducer is held by a robot, X-ray imaging where the source and detector are positioned by robots, and actuated capsule endoscopy, where the capsule is maneuvered by external magnetic actuation. Robot assistance enables the controlled trajectory of the imaging system with high precision and accuracy. This makes it possible to compound acquisitions for increased aperture and for volumetric or tomographic imaging, to track medical instrumentation, and to adjust imaging trajectory in a feedback loop as a function of the patient. Intraoperative robotic medical imaging can provide valuable information to the physician and facilitates the registration of preoperative imaging to the patient. In this review article, we describe some of the robotic imaging systems developed for diagnosis and intervention guidance. In particular, based on the surveyed research activity, we will describe our view of the state of the art in ultrasound, endoscopy, X-ray, optical coherence tomography, and nuclear medicine. We will discuss approaches to autonomous scanning and physics-driven approaches such as elastography and photoacoustic tomography, where the accurate placement and trajectory control of the imaging system using a robot are of paramount importance. We will map out the current state of the art and discuss potential avenues of research.