@article {Metaxas2008, title = {11th International Conference, New York, NY, USA, September 6-10, 2008 Proceedings, Part II Preface}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {11}, number = {Pt 2}, year = {2008}, pages = {V{\textendash}VIII}, keywords = {Computer-Assisted, Diagnostic Imaging, Image Interpretation, Interventional, Radiography, Surgery}, author = {Dimitris Metaxas and Leon Axel and Gabor Fichtinger and Gabor Szekely} } @article {Metaxas2008a, title = {Medical image computing and computer-assisted intervention{\textendash}Medical Image Computing and Computer-Assisted Intervention (MICCAI) 2008 Preface}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {11}, number = {Pt 1}, year = {2008}, pages = {V{\textendash}VII}, publisher = {Rutgers University, Division of Computer, Information Sciences, Piscataway, NJ 08854-8019, USA}, keywords = {Algorithms, Computer-Assisted, Image Enhancement, Image Interpretation, Interventional, methods, Radiography, Surgery, trends}, author = {Dimitris Metaxas and Leon Axel and Gabor Fichtinger and Gabor Szekely} } @article {Fichtinger2008b, title = {Robotic assistance for ultrasound-guided prostate brachytherapy}, journal = {Medical Image Analysis}, volume = {12}, number = {5}, year = {2008}, month = {06/2008}, pages = {535}, publisher = {Queen{\textquoteright}s University; 25 Union Street;725 Goodwin Hall; Kingston; ON; Canada gabor@cs queensu ca}, abstract = {

We present a robotically assisted prostate brachytherapy system, test results in training phantoms, Phase-I clinical trials The system consists of a transrectal ultrasound (TRUS), a spatially co-registered robot,fully integrated with an FDA-approved commercial treatment planning system The salient feature of the system is a small parallel robot affixed to the mounting posts of the template The robot replaces the template interchangeably,using the same coordinate system Established clinical hardware,workflow, calibration remain intact In all phantom experiments,we recorded the first insertion attempt without adjustment All clinically relevant locations in the prostate were reached Non-parallel needle trajectories were achieved The pre-insertion transverse, rotational errors (measured with a Polaris optical tracker relative to the template{\textquoteright}s coordinate frame) were 0 25 mm (STD=0 17 mm), 0 75 degrees (STD=0 37 degrees) In phantoms,needle tip placement errors measured in TRUS were 1 04 mm (STD=0 50mm) A Phase-I clinical feasibility, safety trial has been successfully completed with the system We encountered needle tip positioning errors of a magnitude greater than 4mm in only 2 of 179 robotically guided needles,in contrast to manual template guidance where errors of this magnitude are much more common Further clinical trials are necessary to determine whether the apparent benefits of the robotic assistant will lead to improvements in clinical efficacy, outcomes

}, keywords = {Brachytherapy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, instrumentation, instrumentation/methods, Interventional, Male, Prostatic Neoplasms, Radiotherapy, radiotherapy/ultrasonography, Robotics, Ultrasonography}, doi = {10 1016/j media 2008 06 002}, url = {http://dx doi org/10 1016/j media 2008 06 002}, author = {Gabor Fichtinger and Jonathan Fiene and Christopher Kennedy and Gernot Kronreif and Iulian Iordachita and Danny Y Song and E. Clif Burdette and Peter Kazanzides} } @article {Tokuda2008, title = {Software strategy for robotic transperineal prostate therapy in closed-bore MRI}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {11}, number = {Pt 2}, year = {2008}, pages = {701{\textendash}709}, publisher = {Department of Radiology, Brigham, Women{\textquoteright}s Hospital, Harvard Medical School, 75 Francis St , Boston, MA 02115, USA tokuda@bwh harvard edu}, abstract = {

A software strategy to provide intuitive navigation for MRI-guided robotic transperineal prostate therapy is presented In the system, the robot control unit, the MRI scanner, and open-source navigation software are connected to one another via Ethernet to exchange commands, coordinates, and images Six states of the system called "workphases" are defined based on the clinical scenario to synchronize behaviors of all components The wizard-style user interface allows easy following of the clinical workflow On top of this framework, the software provides features for intuitive needle guidance: interactive target planning; 3D image visualization with current needle position; treatment monitoring through real-time MRI These features are supported by calibration of robot, image coordinates by the fiducial-based registration The performance test shows that the registration error of the system was 2 6 mm in the prostate area, and it displayed real-time 2D image 1 7 s after the completion of image acquisition

}, keywords = {Brachytherapy, Computer-Assisted, Humans, Image Interpretation, Interventional, Magnetic Resonance Imaging, Male, methods, Needles, pathology/radiotherapy, Prostatic Neoplasms, Radiotherapy, Robotics, Software, Software Design}, author = {Junichi Tokuda and Gregory Fischer and Csaba Csoma and Simon DiMaio and David Gobbi and Gabor Fichtinger and Clare M Tempany and Nobuhiko Hata} } @article {Krieger2007a, title = {Design and preliminary accuracy studies of an MRI-guided transrectal prostate intervention system}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {10}, number = {Pt 2}, year = {2007}, pages = {59{\textendash}67}, publisher = {Department of Mechanical Engineering, Johns Hopkins University, Baltimore, USA}, abstract = {

This paper reports a novel system for magnetic resonance imaging (MRI) guided transrectal prostate interventions, such as needle biopsy, fiducial marker placement, and therapy delivery The system utilizes a hybrid tracking method, comprised of passive fiducial tracking for initial registration, subsequent incremental motion measurement along the degrees of freedom using fiber-optical encoders, mechanical scales Targeting accuracy of the system is evaluated in prostate phantom experiments Achieved targeting accuracy, procedure times were found to compare favorably with existing systems using passive, active tracking methods Moreover, the portable design of the system using only standard MRI image sequences, minimal custom scanner interfacing allows the system to be easily used on different MRI scanners

}, keywords = {Algorithms, Artificial Intelligence, Automated, Biopsy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, Image Enhancement, Image Interpretation, Imaging, instrumentation/methods, Interventional, Magnetic Resonance Imaging, Male, methods, Needle, pathology/surgery, Pattern Recognition, Pilot Projects, Prostatectomy, Prostatic Neoplasms, Rectum, Reproducibility of Results, Robotics, Sensitivity, Specificity, Three-Dimensional, User-Computer Interface}, author = {Axel Krieger and Csaba Csoma and Iulian Iordachita and Peter Guion and Anurag K. Singh and Gabor Fichtinger and Whitcomb, Louis L.} } @article {Jain2007, title = {Intra-operative 3D guidance in prostate brachytherapy using a non-isocentric C-arm}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {10}, number = {Pt 2}, year = {2007}, pages = {9{\textendash}17}, publisher = {Johns Hopkins University, USA}, abstract = {

Intra-operative guidance in Transrectal Ultrasound (TRUS) guided prostate brachytherapy requires localization of inserted radioactive seeds relative to the prostate Seeds were reconstructed using a typical C-arm, and exported to a commercial brachytherapy system for dosimetry analysis Technical obstacles for 3D reconstruction on a non-isocentric C-arm included pose-dependent C-arm calibration; distortion correction; pose estimation of C-arm images; seed reconstruction;, C-arm to TRUS registration In precision-machined hard phantoms with 40-100 seeds, we correctly reconstructed 99 8\% seeds with a mean 3D accuracy of 0 68 mm In soft tissue phantoms with 45-87 seeds, clinically realistic 15 degrees C-arm motion, we correctly reconstructed 100\% seeds with an accuracy of 1 3 mm The reconstructed 3D seed positions were then registered to the prostate segmented from TRUS In a Phase-1 clinical trial, so far on 4 patients with 66-84 seeds, we achieved intra-operative monitoring of seed distribution, dosimetry We optimized the 100\% prescribed iso-dose contour by inserting an average of 3 75 additional seeds, making intra-operative dosimetry possible on a typical C-arm, at negligible additional cost to the existing clinical installation

}, keywords = {Algorithms, Brachytherapy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, Imaging, instrumentation/methods, Interventional, Intraoperative Care, Male, methods, Prostatic Neoplasms, Prosthesis Implantation, Radiographic Image Enhancement, Radiographic Image Interpretation, Radiography, radiography/radiotherapy, Radiotherapy, Reproducibility of Results, Sensitivity, Specificity, Three-Dimensional, Tomography, X-Ray Computed}, author = {Ameet K. Jain and Anton Degeut and Iulian Iordachita and Gouthami Chintalapani and Jack Blevins and Le Yi and Elwood Armour and E. Clif Burdette and Danny Y Song and Gabor Fichtinger} } @article {Singh2007a, title = {Patient selection determines the prostate cancer yield of dynamic contrast-enhanced magnetic resonance imaging-guided transrectal biopsies in a closed 3-Tesla scanner}, journal = {British Journal of Urology international}, volume = {101}, number = {2}, year = {2007}, month = {Jan}, pages = {181{\textendash}185}, publisher = {Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1642, USA Anurag Singh@RoswellPark org}, abstract = {

OBJECTIVE: To evaluate the cancer yield of transrectal prostate biopsies in a 3-T magnetic resonance imaging (MRI) scanner in patients with elevated prostate specific antigen (PSA) levels, recent negative transrectal ultrasonography (TRUS)-guided prostate biopsies PATIENTS AND METHODS: Between July 2004, November 2005, patients with at least one previous negative prostate biopsy within the previous 12 months had MRI-guided biopsy of the prostate in a 3-T MRI scanner Patients with previous positive biopsies for cancer were excluded Target selection was based on T2-weighted imaging, dynamic contrast-enhanced (DCE) imaging studies RESULTS: Thirteen patients were eligible; their median (range) age was 61 (47-74) years, PSA value 4 90 (1 3-12 3) ng/mL Most patients had one previous negative biopsy (range 1-4) Four patients had a family history of prostate cancer There were 37 distinct targets based on T2-weighted imaging Fifteen of 16 distinct DCE abnormalities were co-localized with a target based on T2-weighted imaging Despite this correlation, only one of 13 patients had a directed biopsy positive for cancer Including systematic biopsies, two of 13 patients had a biopsy positive for prostate cancer One patient had prostate intraepithelial neoplasia, one had atypical glands in the specimen CONCLUSION: The prostate-cancer yield of transrectal biopsies in a 3-T MRI scanner, among patients with recent negative TRUS-guided prostate biopsies, is similar to repeat systematic TRUS-guided biopsy DCE correlates with T2-imaging but does not appear to improve prostate cancer yield in this population

}, keywords = {Aged, Biopsy, blood, Cohort Studies, Contrast Media, diagnosis, Digital Rectal Examination, Humans, Interventional, Magnetic Resonance Imaging, Male, methods, Middle Aged, Needle, pathology, Patient Selection, Predictive Value of Tests, Prostate, Prostate-Specific Antigen, Prostatic Neoplasms, Sensitivity, Specificity, standards, Ultrasonography}, doi = {10 1111/j 1464-410X 2007 07219 x}, url = {http://dx doi org/10 1111/j 1464-410X 2007 07219 x}, author = {Anurag K. Singh and Axel Krieger and Jean-Baptiste Lattouf and Peter Guion and R.L. Grubb III and Paul Albert and Greg Metzger and Karen Ullman and Sharon Smith and Gabor Fichtinger and Iclal Ocak and Peter Choyke and Cynthia Menard and Jonathan Coleman} } @article {Krupa2007, title = {Real-time tissue tracking with B-mode ultrasound using speckle and visual servoing}, journal = {Tenth International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI)}, volume = {10}, number = {Pt 2}, year = {2007}, pages = {1{\textendash}8}, publisher = {IRISA - INRIA Rennes, France alexandre krupa@irisa fr}, abstract = {

We present a method for real-time tracking of moving soft tissue with B-mode ultrasound (US) The method makes use of the speckle information contained in the US images to estimate the in-plane, out-of-plane motion of a fixed target relative to the ultrasound scan plane The motion information is then used as closed-loop feedback to a robot which corrects for the target motion The concept is demonstrated for translation motions in an experimental setup consisting of an ultrasound speckle phantom, a robot for simulating tissue motion, and a robot that performs motion stabilization from US images This concept shows promise for US-guided procedures that require real-time motion tracking, compensation

}, keywords = {Algorithms, Artificial Intelligence, Computer Systems, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Image Enhancement, Image Interpretation, Imaging, instrumentation/methods, Interventional, methods, Pilot Projects, Reproducibility of Results, Robotics, Sensitivity, Specificity, Surgery, Three-Dimensional, Ultrasonography, User-Computer Interface}, author = {Alexandre Krupa and Gabor Fichtinger and Gregory D. Hager} } @article {Fichtinger2007c, title = {Robotic assistance for ultrasound guided prostate brachytherapy}, journal = {Medical Image Computing and Computer-Assisted Intervention (MICCAI)}, volume = {4791}, year = {2007}, pages = {119{\textendash}127}, publisher = {The Johns Hopkins University, Baltimore, Maryland, USA gabor@cs jhu edu}, abstract = {

We present a robotically assisted prostate brachytherapy system, test results in training phantoms The system consists of a transrectal ultrasound (TRUS), a spatially co-registered robot integrated with an FDA-approved commercial treatment planning system The salient feature of the system is a small parallel robot affixed to the mounting posts of the template The robot replaces the template interchangeably, uses the same coordinate system Established clinical hardware, workflow, calibration are left intact In these experiments, we recorded the first insertion attempt without adjustment All clinically relevant locations were reached Non-parallel needle trajectories were achieved The pre-insertion transverse, rotational errors (measured with Polaris optical tracker relative to the template{\textquoteright}s coordinate frame) were 0 25mm (STD = 0 17mm), 0 75 degrees (STD = 0 37 degrees) The needle tip placement errors measured in TRUS were 1 04mm (STD = 0 50mm) The system is in Phase-I clinical feasibility, safety trials, under Institutional Review Board approval

}, keywords = {Brachytherapy, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Humans, instrumentation/methods, Interventional, Male, Prostatic Neoplasms, Radiotherapy, Radiotherapy Planning, radiotherapy/ultrasonography, Robotics, Ultrasonography}, author = {Gabor Fichtinger and Jonathan Fiene and Christopher Kennedy and Gernot Kronreif and Iulian Iordachita and Danny Y Song and E. Clif Burdette and Peter Kazanzides} } @article {Fischer2007b, title = {Robotic assistant for transperineal prostate interventions in 3T closed MRI}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {10}, number = {Pt 1}, year = {2007}, pages = {425{\textendash}433}, publisher = {Center for Computer Integrated Surgery, Johns Hopkins University, USA gfischer@jhu edu}, abstract = {

Numerous studies have demonstrated the efficacy of image-guided needle-based therapy, biopsy in the management of prostate cancer The accuracy of traditional prostate interventions performed using transrectal ultrasound (TRUS) is limited by image fidelity, needle template guides, needle deflection, tissue deformation Magnetic Resonance Imaging (MRI) is an ideal modality for guiding, monitoring such interventions due to its excellent visualization of the prostate, its sub-structure, surrounding tissues We have designed a comprehensive robotic assistant system that allows prostate biopsy, brachytherapy procedures to be performed entirely inside a 3T closed MRI scanner We present a detailed design of the robotic manipulator, an evaluation of its usability, MR compatibility

}, keywords = {anatomy /\&/ histology/surgery, Computer-Assisted, Equipment Design, Equipment Failure Analysis, Image Interpretation, instrumentation/methods, Interventional, Magnetic Resonance Imaging, Perineum, Prostatectomy, Robotics, Surgery}, author = {Gregory Fischer and Simon DiMaio and Iulian Iordachita and Gabor Fichtinger} } @article {Boctor2006b, title = {Ultrasound monitoring of tissue ablation via deformation model and shape priors}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {9}, number = {Pt 2}, year = {2006}, pages = {405{\textendash}412}, abstract = {

A rapid approach to monitor ablative therapy through optimizing shape, elasticity parameters is introduced Our motivating clinical application is targeting, intraoperative monitoring of hepatic tumor thermal ablation, but the method translates to the generic problem of encapsulated stiff masses (solid organs, tumors, ablated lesions, etc ) in ultrasound imaging The approach involves the integration of the following components: a biomechanical computational model of the tissue, a correlation approach to estimate/track tissue deformation, and an optimization method to solve the inverse problem, recover the shape parameters in the volume of interest Successful convergence, reliability studies were conducted on simulated data Then ex-vivo studies were performed on 18 ex-vivo bovine liver samples previously ablated under ultrasound monitoring in controlled laboratory environment While B-mode ultrasound does not clearly identify the development of necrotic lesions, the proposed technique can potentially segment the ablation zone The same framework can also yield both partial, full elasticity reconstruction

}, keywords = {Algorithms, Animals, Automated, Biological, Cattle, Computer-Assisted, Elasticity, Hepatectomy, Image Enhancement, Image Interpretation, Imaging, Interventional, Liver, Mechanical, methods, Models, Pattern Recognition, physiology/surgery/ultrasonography, Reproducibility of Results, Sensitivity, Specificity, Statistical, Stress, Subtraction Technique, Surgery, Three-Dimensional, Ultrasonography}, author = {Emad Boctor and Michelle de Oliveira and Michael Choti and Roger Ghanem and Russell H. Taylor and Gregory D. Hager and Gabor Fichtinger} } @article {Fichtinger2005, title = {Image overlay for CT-guided needle insertions}, journal = {Journal of Computer Aided Surgery}, volume = {10}, number = {4}, year = {2005}, month = {Jul}, pages = {241{\textendash}255}, abstract = {

OBJECTIVE: We present a 2D image overlay device to assist needle placement on computed tomography (CT) scanners MATERIALS AND METHODS: The system consists of a flat display, a semitransparent mirror mounted on the gantry When the physician looks at the patient through the mirror, the CT image appears to be floating inside the body with correct size, position as if the physician had 2D {\textquoteright}X-ray vision{\textquoteright} The physician draws the optimal path on the CT image The composite image is rendered on the display, thus reflected in the mirror The reflected image is used to guide the physician in the procedure In this article, we describe the design, various embodiments of the 2D image overlay system, followed by the results of phantom, cadaver experiments in multiple clinical applications RESULTS: Multiple skeletal targets were successfully accessed with one insertion attempt Generally, successful access was recorded on liver targets when a clear path opened, but the number of attempts, accuracy showed variability because of occasional lack of access Soft tissue deformation further reduced the accuracy, consistency in comparison to skeletal targets CONCLUSION: The system demonstrated strong potential for reducing faulty needle insertion attempts, thereby reducing X-ray dose, patient discomfort

}, keywords = {Animals, Biopsy, Cadaver, Calibration, Computer-Assisted, Equipment Design, Humans, Image Processing, Imaging, instrumentation, Interventional, Needle, Phantoms, Radiography, Swine, Tomography, User-Computer Interface, X-Ray Computed}, doi = {10 1080/10929080500230486}, url = {http://dx doi org/10 1080/10929080500230486}, author = {Gabor Fichtinger and Anton Degeut and Gregory Fischer and Iulian Iordachita and Emese Balogh and Ken Masamune and Russell H. Taylor and Laura Fayad and Michelle de Oliveira and James Zinreich} } @article {Boctor2005, title = {Real-time quality control of tracked ultrasound}, journal = {Medical image computing and computer-assisted intervention (MICCAI)}, volume = {8}, number = {Pt 1}, year = {2005}, pages = {621{\textendash}630}, abstract = {

The overwhelming majority of intra-operative hazard situations in tracked ultrasound (US) systems are attributed to failure of registration between tracking, imaging coordinate frames We introduce a novel methodology for eal-time in-vivo quality control of tracked US systems, in order to capture registration failures during the clinical procedure In effect, we dynamically recalibrate the tracked US system for rotation, scale factor, and in-plane position offset up to a scale factor We detect any unexpected change in these parameters through capturing discrepancies in the resulting calibration matrix, thereby assuring quality (accuracy, consistency) of the tracked system No phantom is used for the recalibration We perform the task of quality control in the background, transparently to the clinical user while the subject is being scanned We present the concept, mathematical formulation, and experimental evaluation in-vitro This new method can play an important role in guaranteeing accurate, consistent, and reliable performance of tracked ultrasound

}, keywords = {Algorithms, Computer Systems, Computer-Assisted, Health Care, Humans, Image Enhancement, Image Interpretation, Interventional, methods, Quality Assurance, Quality Control, Reproducibility of Results, Sensitivity, Specificity, Surgery, Ultrasonography, User-Computer Interface}, author = {Emad Boctor and Iulian Iordachita and Gabor Fichtinger and Gregory D. Hager} }