Dr.-Ing. Darko Ojdanic

Robot-supported MRI Biopsy

(Dienstag, 15.15 Uhr, Schinkelsaal)

Darko Ojdanic

Performing biopsies is one of the essential and routine tasks in detecting cancer, in the best case early enough to perform (local) therapy. At the same time, hitting the right spot with the needle is a crucial but non-trivial task. For example, in case of prostate cancer, ultrasound (US) guided biopsies is a well-established clinical process, which is also called “blind” as the doctor does not necessarily see the target in US images. That is why often 10-12 random samples are taken, hoping not to miss the cancer, if it is present at all. Several concepts and tools appeared for improving this and making it more “guided“. One option is to provide image fusion of MRI scans, where the targets may be seen, within the US-guided session. This already improves the outcome. Another way is to perform the biopsy directly within the MRI, which promises even better detection rates.

Mechanical devices for positioning the needle guide are already commercially available. This has a drawback within the workflow, as the radiologist has to continuously move in and out of the MRI room for making the image, checking and repositioning. Providing a robot for that task is a natural next development step. On the other side, the imaging environment of the MR scanner imposes highly complex requirements for any automation device. Therefore, only few techniques for actuators are particularly suitable: hydraulic, pneumatic, piezo-electric etc. The spin-off company Soteria Medical introduced recently a five degrees of freedom pneumatic robot dedicated for MRI-based prostate biopsy. The software for this tele-manipulation positioning tool is developed by Fraunhofer MEVIS. It supports the workflow with PACS communication for images, semi-automatic needle guide segmentation and robot calibration, motion planning and execution.

Within the talk, the technical focus will be set on the software part. Part of the talk will deal with the aspect of quality assurance during development within research institutes, and its impact on successful “research to product” transfer. Moreover, some general considerations regarding development of devices for MRI as well as technical and socio-economical dilemma of MRI-guided vs. MRI-US-fusion will be addressed and opened for discussion.

Dr. Darko Ojdanic
Fraunhofer MEVIS Bremen