@article {Siefabadi2012a,
	title = {Acuracy Study of a MRI-guided Robotic System for Prostate Needle Placement},
	journal = {The International Journal of Medical Robotics and Computer Assisted Surgery (IJMRCAS)},
	year = {2012},
	abstract = {<p>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{\textquoteright}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{\textquoteright}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{\textquoteright}s targeting accuracy was 0.71 mm (STD=0.21mm) after robot calibration. The robot{\textquoteright}s repeatability was 0.13 mm. Sterilization had no noticeable influence on the robot{\textquoteright}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.</p>
},
	doi = {10.1002/rcs.1440},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/rcs.1440/abstract},
	author = {Reza Seifabadi and Nathan Bongjoon Cho and Sam Sang-Eun Song and Junichi Tokuda and Nobuhiko Hata and Clare M Tempany and Gabor Fichtinger and Iulian Iordachita}
}
