| Title | Acuracy Study of a MRI-guided Robotic System for Prostate Needle Placement |
| Publication Type | Journal Article |
| Year of Publication | 2012 |
| Refereed Designation | Refereed |
| Authors | Seifabadi, R., N B. Cho, S S-E. Song, J. Tokuda, N. Hata, C. M. Tempany, G. Fichtinger, and I. Iordachita |
| Journal | The International Journal of Medical Robotics and Computer Assisted Surgery (IJMRCAS) |
| Abstract | Background: Accurate needle placement is the first concern in percutaneous MRI-guided
prostate interventions. In this phantom study, different sources contributing to the overall needle
placement error of a MRI-guided robot for prostate biopsy have been identified, quantified, and
minimized to the possible extent.
Methods and Materials: The overall needle placement error of the system was evaluated in a
prostate phantom. This error was broken into two parts: the error associated with the robotic
system (called before-insertion error) and the error associated with needle-tissue interaction
(called due-to-insertion error). The before-insertion error was measured directly in a soft
phantom and different sources contributing into this part were identified and quantified. A
calibration methodology was developed to minimize the 4-DOF manipulator’s error. The due-toinsertion
error was indirectly approximated by comparing the overall error and the beforeinsertion
error. The effect of sterilization on the manipulator’s accuracy and repeatability was
also studied.
Results: The average overall system error in phantom study was 2.5 mm (STD=1.1mm). The
average robotic system error in super soft phantom was 1.3 mm (STD=0.7 mm). Assuming
orthogonal error components, the needle-tissue interaction error was approximated to be 2.13
mm thus having larger contribution to the overall error. The average susceptibility artifact shift
was 0.2 mm. The manipulator’s targeting accuracy was 0.71 mm (STD=0.21mm) after robot
calibration. The robot’s repeatability was 0.13 mm. Sterilization had no noticeable influence on
the robot’s accuracy and repeatability.
Conclusions: The experimental methodology presented in this paper may help researchers to
identify, quantify, and minimize different sources contributing into the overall needle placement
error of an MRI-guided robotic system for prostate needle placement. In the robotic system
analyzed here, the overall error of the studied system remained within the acceptable range. |
| URL | http://onlinelibrary.wiley.com/doi/10.1002/rcs.1440/abstract |
| DOI | 10.1002/rcs.1440 |
| PerkWeb Citation Key | Siefabadi2012a |
