Frederick Kelcz MD, PhD, Presenter: Nothing to Disclose

Raymond Harter MS, Abstract Co-Author: President, Marvel Medtech, LLC

Ethan K. Brodsky PhD, Abstract Co-Author: Nothing to Disclose

Walter F. Block PhD, Abstract Co-Author: Research support, General Electric Company

Roberta Marie Strigel MD, MS, Abstract Co-Author: Speaker, Bracco Group

Graham T. Reitz, Abstract Co-Author: Research funded, Marvel Medtech, LLC

Sergey N. Kuro, Abstract Co-Author: Employee, Marvel Medtech, LLC

The current method of MRI-assisted breast biopsy requires that the patient be moved into the bore for planning and verification, then out of the bore for the biopsy procedure. This approach is subject to error due to patient motion or trocar-induced lesion displacement between image sets. We are developing an in-bore system for robotic interactive MR image guided interventions (iMR-IGI) using MRI-compatible actuators and a ceramic trocar. This will allow the radiologist to efficiently and rapidly control, in real time, all aspects of the intervention process.

We have developed a multi-degree-of-freedom robotic proof-of-concept prototype system for in-bore MR image guided biopsy (IGB) trocar placement. The MRI-compatible system configuration is not limited to lateral or medial access to the breast and  is constructed so as to permit a real-time imaging interface to the MRI scanner.  The system also has its own integrated radiofrequency (RF) breast coil to maximize signal to noise ratio (SNR) and uses piezoelectric actuators. The in-bore tool positioner is mounted on a circular track surrounding the breast cup and RF coil.

Video will be presented, taken during real-time MR imaging, demonstrating robotic controlled insertion of the fluid filled, MR visible ceramic trocar into a gel breast phantom.  We tested SNR levels using phantoms with all electronics unpowered (SNR = 44) vs. a fully activated state (SNR=31) using an 8 channel commercial receive breast coil (GE Healthcare, Waukesha, WI). While SNR degradation is measurable in this early prototype, it is modest and acceptable given the clinical requirements for identifying and tracking a known lesion.

We have demonstrated proof-of-concept novel in-bore actuation capability with concurrent real-time imaging.  Our proposed system will provide a rapid, interactive method for placing diagnostic and therapeutic tools into the breast under real-time MRI guidance.

Some literature has used the term “real-time”  to simply describe a surgery that can be completed entirely within the MR suite.  In such cases, the imaging guidance itself is not in real-time and device guidance is performed by iterating between diagnostic imaging and discrete device manipulations.  We have demonstrated novel true in-bore actuation capability with concurrent real-time imaging, now to be applied to the breast, but with potential for use in other body regions.

Kelcz, F, Harter, R, Brodsky, E, Block, W, Strigel, R, Reitz, G, Kuro, S, Initial Testing of an In-bore MRI-guided Real-time Breast Biopsy System.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004669.html