@article {Dehghan2012a, title = {Ultrasound{\textendash}fluoroscopy registration for prostate brachytherapy dosimetry}, journal = {Medical Image Analysis}, volume = {16}, year = {2012}, month = {2012}, pages = {1347-1358}, keywords = {Fluoroscopy, Prostate brachytherapy, Registration, Ultrasound}, doi = {http://dx.doi.org/10.1016/j.media.2012.06.001}, url = {http://www.sciencedirect.com/science/article/pii/S1361841512000813}, author = {Ehsan Dehghan and Junghoon Lee and Pascal Fallavollita and Nathanael Kuo and Anton Degeut and Yi Le and E. Clif Burdette and Danny Y Song and Jerry L. Prince and Gabor Fichtinger} } @article {Sciubba2010, title = {Percutaneous computed tomography fluoroscopy-guided conformal ultrasonic ablation of vertebral tumors in a rabbit tumor model. Laboratory investigation.}, journal = {J Neurosurg Spine}, volume = {13}, number = {6}, year = {2010}, month = {Dec}, pages = {773{\textendash}779}, publisher = {Department of Neurosurgery, Johns Hopkins University, Baltimore, Maryland 21287, USA. dsciubb1@jhmi.edu}, abstract = {

Radiofrequency ablation (RFA) has proven to be effective for treatment of malignant and benign tumors in numerous anatomical sites outside the spine. The major challenge of using RFA for spinal tumors is difficulty protecting the spinal cord and nerves from damage. However, conforming ultrasound energy to match the exact anatomy of the tumor may provide successful ablation in such sensitive locations. In a rabbit model of vertebral body tumor, the authors have successfully ablated tumors using an acoustic ablator placed percutaneously via computed tomography fluoroscopic (CTF) guidance.Using CTF guidance, 12 adult male New Zealand White rabbits were injected with VX2 carcinoma cells in the lowest lumbar vertebral body. At 21 days, a bone biopsy needle was placed into the geographical center of the lesion, down which an acoustic ablator was inserted. Three multisensor thermocouple arrays were placed around the lesion to provide measurement of tissue temperature during ablation, at thermal doses ranging from 100 to 1,000,000 TEM (thermal equivalent minutes at 43{\textdegree}C), and tumor volumes were given a tumoricidal dose of acoustic energy. Animals were monitored for 24 hours and then sacrificed. Pathological specimens were obtained to determine the extent of tumor death and surrounding tissue damage. Measured temperature distributions were used to reconstruct volumetric doses of energy delivered to tumor tissue, and such data were correlated with pathological findings.All rabbits were successfully implanted with VX2 cells, leading to a grossly apparent spinal and paraspinal tissue mass. The CTF guidance provided accurate placement of the acoustic ablator in all tumors, as corroborated through gross and microscopic histology. Significant tumor death was noted in all specimens without collateral damage to nearby nerve tissue. Tissue destruction just beyond the margin of the tumor was noted in some but not all specimens. No neurological deficits occurred in response to ablation. Reconstruction of measured temperature data allowed accurate assessment of volumetric dose delivered to tissues.Using a rabbit intravertebral tumor model, the authors have successfully delivered tumoricidal doses of acoustic energy via a therapeutic ultrasound ablation probe placed percutaneously with CTF guidance. The authors have thus established the first technical and preclinical feasibility study of controlled ultrasound ablation of spinal tumors in vivo.

}, keywords = {Animals, Carcinoma, Catheter Ablation, Fluoroscopy, instrumentation/methods, Lumbar Vertebrae, Male, Neoplasm Transplantation, Rabbits, Spinal Neoplasms, therapy, Tomography, X-Ray Computed}, doi = {10.3171/2010.5.SPINE09266}, url = {http://dx.doi.org/10.3171/2010.5.SPINE09266}, author = {Daniel M Sciubba and E. Clif Burdette and Jennifer J Cheng and William A Pennant and Joseph C Noggle and Rory J Petteys and Christopher Alix and Chris J Diederich and Gabor Fichtinger and Ziya L Gokaslan and Kieran P Murphy} } @article {Jain2006a, title = {C-arm tracking and reconstruction without an external tracker}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {9}, number = {Pt 1}, year = {2006}, pages = {494{\textendash}502}, publisher = {Department of Computer Science, Johns Hopkins University, USA}, abstract = {

For quantitative C-arm fluoroscopy, we have developed a unified mathematical framework to tackle the issues of intra-operative calibration, pose estimation, correspondence, reconstruction, without the use of optical/electromagnetic trackers or precision-made fiducial fixtures Our method uses randomly distributed unknown points in the imaging volume, either naturally present or induced by randomly sticking beads or other simple markers in the image pace After these points are segmented, a high dimensional non-linear optimization computes all unknown parameters for calibration, C-arm pose, correspondence, reconstruction Preliminary phantom experiments indicate an average C-arm tracking accuracy of 0 9 degrees, a 3D reconstruction error of 0 8 mm, with an 80 region of convergence for both the AP, lateral axes The method appears to be sufficiently accurate for many clinical applications, and appealing since it works without any external instrumentation, does not interfere with the workspace

}, keywords = {Algorithms, Calibration, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Fluoroscopy, Imaging, instrumentation/methods, methods, Radiographic Image Enhancement, Radiographic Image Interpretation, Reproducibility of Results, Sensitivity, Specificity, Three-Dimensional}, author = {Ameet K. Jain and Gabor Fichtinger} } @article {Jain2005, title = {C-arm calibration-is it really necessary?}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {8}, number = {Pt 1}, year = {2005}, pages = {639{\textendash}646}, abstract = {

C-arm fluoroscopy is modelled as a perspective projection, the parameters of which are estimated through a calibration procedure It has been universally accepted that precise intra-procedural calibration is a prerequisite for accurate quantitative C-arm fluoroscopy guidance Calibration, however, significantly adds to system complexity, which is a major impediment to clinical practice We challenge the status quo by questioning the assumption that precise intra-procedural calibration is really necessary We derived theoretical bounds for the sensitivity of 3D measurements to mis-calibration Experimental results corroborated the theory in that mis-calibration in the focal spot by as much as 50 mm still allows for tracking with an accuracy of 0 5 mm in translation, 0 65 degrees in rotation, and such mis-calibration does not impose any additional error on the reconstruction of small objects

}, keywords = {Algorithms, Calibration, Computer-Assisted, Equipment Failure Analysis, Fluoroscopy, Imaging, instrumentation/methods/standards, methods/standards, Radiographic Image Enhancement, Radiographic Image Interpretation, Reproducibility of Results, Sensitivity, Specificity, Three-Dimensional, United States}, author = {Ameet K. Jain and Ryan Kon and Yu Zhou and Gabor Fichtinger} } @article {Jain2005a, title = {FTRAC}, journal = {Journal of Medical Physics}, volume = {32}, number = {10}, year = {2005}, month = {Oct}, pages = {3185{\textendash}3198}, abstract = {

C-arm fluoroscopy is ubiquitous in contemporary surgery, but it lacks the ability to accurately reconstruct three-dimensional (3D) information A major obstacle in fluoroscopic reconstruction is discerning the pose of the x-ray image, in 3D space Optical/magnetic trackers tend to be prohibitively expensive, intrusive, cumbersome in many applications We present single-image-based fluoroscope tracking (FTRAC) with the use of an external radiographic fiducial consisting of a mathematically optimized set of ellipses, lines, and points This is an improvement over contemporary fiducials, which use only points The fiducial encodes six degrees of freedom in a single image by creating a unique view from any direction A nonlinear optimizer can rapidly compute the pose of the fiducial using this image The current embodiment has salient attributes: small dimensions (3 x 3 x 5 cm); need not be close to the anatomy of interest;, accurately segmentable We tested the fiducial, the pose recovery method on synthetic data, also experimentally on a precisely machined mechanical phantom Pose recovery in phantom experiments had an accuracy of 0 56 mm in translation, 0 33 degrees in orientation Object reconstruction had a mean error of 0 53 mm with 0 16 mm STD The method offers accuracies similar to commercial tracking systems, and appears to be sufficiently robust for intraoperative quantitative C-arm fluoroscopy Simulation experiments indicate that the size can be further reduced to 1 x 1 X 2 cm, with only a marginal drop in accuracy

}, keywords = {Algorithms, Computer-Assisted, Fluoroscopy, Imaging, Information Storage, instrumentation/methods, methods, Phantoms, Radiographic Image Enhancement, Radiographic Image Interpretation, Reproducibility of Results, Retrieval, Sensitivity, Specificity, Three-Dimensional}, author = {Ameet K. Jain and Tabish Mustufa and Yu Zhou and E. Clif Burdette and Gregory Chirikjian and Gabor Fichtinger} } @article {Cleary2005, title = {Precision placement of instruments for minimally invasive procedures using a "needle driver" robot}, journal = {international journal of medical robotics computer assisted surgery MRCAS}, volume = {1}, number = {2}, year = {2005}, month = {Jan}, pages = {40{\textendash}47}, abstract = {

Medical practice continues to move toward less invasive procedures Many of these procedures require the precision placement of a needle in the anatomy Over the past several years, our research team has been investigating the use of a robotic needle driver to assist the physician in this task This paper summarizes our work in this area The robotic system is briefly described, followed by a description of a clinical trial in spinal nerve blockade The robot was used under joystick control to place a 22 gauge needle in the spines of 10 patients using fluoroscopic imaging The results were equivalent to the current manual procedure We next describe our follow-up clinical application in lung biopsy for lung cancer screening under CT fluoroscopy The system concept is discussed, the results of a phantom study are presented A start-up company named ImageGuide has recently been formed to commercialize the robot Their revised robot design is presented, along with plans to install a ceiling-mounted version of the robot in the CT fluoroscopy suite at Georgetown University

}, keywords = {Biopsy, Cadaver, Equipment Design, Fluoroscopy, Humans, Imaging, instrumentation, instrumentation/methods, Lung, Lung Neoplasms, methods, Minimally Invasive, Needles, Nerve Block, pathology, pathology/radiography, Phantoms, Randomized Controlled Trials as Topic, Robotics, Spinal Nerves, Surgical Procedures, Tomography, X-Ray Computed}, doi = {10 1002/rcs 40}, url = {http://dx doi org/10 1002/rcs 40}, author = {Kevin Cleary and Vance Watson and David Lindisch and Russell H. Taylor and Gabor Fichtinger and Sheng Xu and Charles White and John Donlon and Michael Taylor and Alexandru Patriciu and Dumitru Mazilu and Dan Stoianovici} }