@article {DiMaio2007b, title = {Challenges in image-guided therapy system design}, journal = {Neuroimage}, volume = {37 Suppl 1}, year = {2007}, pages = {S144{\textendash}S151}, publisher = {Brigham, Women{\textquoteright}s Hospital, 75 Francis St , Boston, MA 02115, USA simond@bwh harvard edu}, abstract = {

System development for image-guided therapy (IGT), or image-guided interventions (IGI), continues to be an area of active interest across academic, industry groups This is an emerging field that is growing rapidly: major academic institutions, medical device manufacturers have produced IGT technologies that are in routine clinical use, dozens of high-impact publications are published in well regarded journals each year, and several small companies have successfully commercialized sophisticated IGT systems In meetings between IGT investigators over the last two years, a consensus has emerged that several key areas must be addressed collaboratively by the community to reach the next level of impact, efficiency in IGT research, development to improve patient care These meetings culminated in a two-day workshop that brought together several academic, industrial leaders in the field today The goals of the workshop were to identify gaps in the engineering infrastructure available to IGT researchers, develop the role of research funding agencies, the recently established US-based National Center for Image Guided Therapy (NCIGT), and ultimately to facilitate the transfer of technology among research centers that are sponsored by the National Institutes of Health (NIH) Workshop discussions spanned many of the current challenges in the development, deployment of new IGT systems Key challenges were identified in a number of areas, including: validation standards; workflows, use-cases, and application requirements; component reusability;, device interface standards This report elaborates on these key points, proposes research challenges that are to be addressed by a joint effort between academic, industry, and NIH participants

}, keywords = {adverse effects/instrumentation/trends, Algorithms, Computational Biology, Computer Systems, Computer-Assisted, Humans, instrumentation/trends, Knowledge Bases, Models, National Institutes of Health (U S ), Neurosurgical Procedures, Organizational, Outcome Assessment (Health Care), Reproducibility of Results, Robotics, Software, Surgery, Treatment Outcome, United States}, doi = {10 1016/j neuroimage 2007 04 026}, url = {http://dx doi org/10 1016/j neuroimage 2007 04 026}, author = {Simon DiMaio and Tina Kapur and Kevin Cleary and Stephen Aylward and Peter Kazanzides and Kirby Vosburgh and Randy Ellis and James Duncan and Keyvan Farahani and Heinz Lemke and T. M. Peters and William Bill Lorensen and David Gobbi and John Haller and Laurence Larry Clarke and Stephen Pizer and Russell H. Taylor and Robert L. Galloway, Jr. and Gabor Fichtinger and Nobuhiko Hata and Kimberly Lawson and Clare M Tempany and Ron Kikinis and Ferenc Jolesz} } @article {Singh2007b, title = {Simultaneous integrated boost of biopsy proven and MRI defined dominant intra-prostatic lesions to 95 Gray with IMRT: early results of a phase I NCI study}, journal = {Radiation Oncology}, volume = {2}, year = {2007}, pages = {36}, publisher = {Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, USA singhanu@yahoo com}, abstract = {

BACKGROUND: To assess the feasibility, early toxicity of selective, IMRT-based dose escalation (simultaneous integrated boost) to biopsy proven dominant intra-prostatic lesions visible on MRI METHODS: Patients with localized prostate cancer, an abnormality within the prostate on endorectal coil MRI were eligible All patients underwent a MRI-guided transrectal biopsy at the location of the MRI abnormality Gold fiducial markers were also placed Several days later patients underwent another MRI scan for fusion with the treatment planning CT scan This fused MRI scan was used to delineate the region of the biopsy proven intra-prostatic lesion A 3 mm expansion was performed on the intra-prostatic lesions, defined as a separate volume within the prostate The lesion + 3 mm, the remainder of the prostate + 7 mm received 94 5/75 6 Gray (Gy) respectively in 42 fractions Daily seed position was verified to be within 3 mm RESULTS: Three patients were treated Follow-up was 18, 6, and 3 months respectively Two patients had a single intra-prostatic lesion One patient had 2 intra-prostatic lesions All four intra-prostatic lesions, with margin, were successfully targeted, treated to 94 5 Gy Two patients experienced acute RTOG grade 2 genitourinary (GU) toxicity One had grade 1 gastrointestinal (GI) toxicity All symptoms completely resolved by 3 months One patient had no acute toxicity CONCLUSION: These early results demonstrate the feasibility of using IMRT for simultaneous integrated boost to biopsy proven dominant intra-prostatic lesions visible on MRI The treatment was well tolerated

}, keywords = {adverse effects/methods, Biopsy, epidemiology, epidemiology/radiotherapy, Follow-Up Studies, Humans, Intensity-Modulated, Magnetic Resonance Imaging, Male, National Cancer Institute (U S ), Patient Selection, Prostatic Neoplasms, Questionnaires, Radiotherapy, Radiotherapy Dosage, United States}, doi = {10 1186/1748-717X-2-36}, url = {http://dx doi org/10 1186/1748-717X-2-36}, author = {Anurag K. Singh and Peter Guion and Nancy Sears-Crouse and Karen Ullman and Sharon Smith and Paul Albert and Gabor Fichtinger and Peter Choyke and Sheng Xu and Jochen Kruecker and Bradford Wood and Axel Krieger and Holly Ning} } @article {Fischer2007a, title = {Validation system of MR image overlay and other needle insertion techniques}, journal = {Studies in health technology and informatics}, volume = {125}, year = {2007}, pages = {130{\textendash}135}, publisher = {Engineering Research Center, Johns Hopkins University, Baltimore, MD, USA}, abstract = {

In order to develop accurate, effective augmented reality (AR) systems used in MR, CT guided needle placement procedures, a comparative validation environment is necessary Clinical equipment is prohibitively expensive, often inadequate for precise measurement Therefore, we have developed a laboratory validation system for measuring operator performance using different assistance techniques Electromagnetically tracked needles are registered with the preoperative plan to measure placement accuracy, the insertion path The validation system provides an independent measure of accuracy that can be applied to varying methods of assistance ranging from augmented reality guidance methods to tracked navigation systems, autonomous robots In preliminary studies, this validation system is used to evaluate the performance of the image overlay, bi-plane laser guide, and traditional freehand techniques

}, keywords = {Computer Simulation, Magnetic Resonance Imaging, Needles, Reproducibility of Results, Tomography, United States, X-Ray Computed}, author = {Gregory Fischer and Eva Dyer and Csaba Csoma and Anton Degeut and Gabor Fichtinger} } @article {Boctor2006a, title = {Bootstrapped ultrasound calibration}, journal = {Studies in health technology and informatics}, volume = {119}, year = {2006}, pages = {61{\textendash}66}, publisher = {Engineering Research Center, Johns Hopkins University, USA}, abstract = {

This paper introduces an enhanced (bootstrapped) method for tracked ultrasound probe calibration Prior to calibration, a position sensor is used to track an ultrasound probe in 3D space, while the US image is used to determine calibration target locations within the image From this information, an estimate of the transformation matrix of the scan plane with respect to the position sensor is computed While all prior calibration methods terminate at this phase, we use this initial calibration estimate to bootstrap an additional optimization of the transformation matrix on independent data to yield the minimum reconstruction error on calibration targets The bootstrapped workflow makes use of a closed-form calibration solver, associated sensitivity analysis, allowing for rapid, robust convergence to an optimal calibration matrix Bootstrapping demonstrates superior reconstruction accuracy

}, keywords = {Calibration, Imaging, standards, Three-Dimensional, Ultrasonography, United States}, author = {Emad Boctor and Iulian Iordachita and Michael Choti and Gregory D. Hager and Gabor Fichtinger} } @article {Fischer2006, title = {MRI image overlay: applications to arthrography needle insertion}, journal = {Studies in health technology and informatics}, volume = {119}, year = {2006}, pages = {150{\textendash}155}, abstract = {

Magnetic Resonance Imaging (MRI) has unmatched potential for planning, guiding, monitoring, controlling interventions MR arthrography (MRA) is the imaging gold standard to assess small ligament, fibrocartilage injury in joints In contemporary practice, MRA consists of two consecutive sessions: 1) an interventional session where a needle is driven to the joint space, gadolinium contrast is injected under fluoroscopy or CT guidance 2) A diagnostic MRI imaging session to visualize the distribution of contrast inside the joint space, evaluate the condition of the joint Our approach to MRA is to eliminate the separate radiologically guided needle insertion, contrast injection procedure by performing those tasks on conventional high-field closed MRI scanners We propose a 2D augmented reality image overlay device to guide needle insertion procedures This approach makes diagnostic high-field magnets available for interventions without a complex, expensive engineering entourage

}, keywords = {Arthrography, Humans, Magnetic Resonance Imaging, Needles, United States, User-Computer Interface}, author = {Gregory Fischer and Anton Degeut and Daniel Schlattman and Russell H. Taylor and Laura Fayad and James Zinreich and Gabor Fichtinger} } @article {DiMaio2006, title = {Needle artifact localization in 3T MR images}, journal = {Studies in health technology and informatics}, volume = {119}, year = {2006}, pages = {120{\textendash}125}, publisher = {Brigham, Women{\textquoteright}s Hospital, Harvard Medical School, Boston 02115, USA simond@bwh harvard edu}, abstract = {

This work explores an image-based approach for localizing needles during MRI-guided interventions, for the purpose of tracking, navigation Susceptibility artifacts for several needles of varying thickness were imaged, in phantoms, using a 3 tesla MRI system, under a variety of conditions The relationship between the true needle positions, the locations of artifacts within the images, determined both by manual, automatic segmentation methods, have been quantified, are presented here

}, keywords = {Artifacts, Magnetic Resonance Imaging, Needles, United States}, author = {Simon DiMaio and Daniel Kacher and Randy Ellis and Gabor Fichtinger and Nobuhiko Hata and Gary Zientara and Lawrence Panych and Ron Kikinis and Ferenc Jolesz} } @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} }