Hao Su MS, Presenter: Nothing to Disclose

Gregory Alexander Cole MS, Abstract Co-Author: Nothing to Disclose

Nobuhiko Hata PhD, Abstract Co-Author: Research Consultant, AZE, Ltd

Clare M. C. Tempany-Afdhal MD, Abstract Co-Author: Nothing to Disclose

Gregory Fischer, Abstract Co-Author: Nothing to Disclose

The experiments demonstrate the capability of image-guided needle insertion using real-time MR images. Interactive imaging enables closed-loop feedback, thus potentially increasing the targeting accuracy during percutaneous needle placement procedures performed in MRI. This work is supported by CDMRP PCRP W81XWH-09-1-0191 and NIH awards 5P41RR019703, 5P01CA067165, 1R01CA111288.

Magnetic resonance imaging can provide high resolution multi-parametric imaging, large soft tissue contrast, and interactive image updates making it an ideal guidance modality for needle-based prostate interventions. In this study, an MRI-compatible robotic assistant for needle placement is designed for image-guided prostate interventions. The system is intended to provide increased positioning accuracy through the use of precision motion and image feedback. This piezoelectrically actuated system enables acquisition of interactively updated images during robot motion in situ. These images enable real-time guidance and of needle tracking in MRI which may be used for image-guided closed loop control of needle placement.

MRI compatibility of the needle placement robotic system was first evaluated in a Philips Achieva 3T scanner with typical protocols (T1, T2, FGRE and EPI). Signal to noise ratio (SNR) was evaluated for each imaging sequence in a baseline state and during synchronous robot motion and imaging. There was no statistically significant difference in the SNR of the baseline image set and that of the robot moving during imaging for all four sequences (p<0.05). Functional spin-echo planar imaging was then utilized to monitor needle placement at 2.5Hz update rates during robotic needle insertion. The needle shaft and tip trajectories were able to be clearly visualized in the phantom images, and the robotic system did not cause significant degradation of image quality.

The MRI compatibility evaluation demonstrates the ability to use robotic needle placement during imaging without negatively impacting image quality. The improvement in compatibility performance is significant compared with the most recent other reported results showing 40%−60% signal-to-noise reduction under motion.

Su, H, Cole, G, Hata, N, Tempany-Afdhal, C, Fischer, G, Real-time MRI-guided Transperineal Needle Placement Prostate Interventions with Piezoelectrically Actuated Robotic Assistance.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11003223.html