@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 {Fischer2007, title = {MRI image overlay: application to arthrography needle insertion}, journal = {Journal of Computer Aided Surgery}, volume = {12}, number = {1}, year = {2007}, month = {Jan}, pages = {2{\textendash}14}, publisher = {Engineering Research Center, Johns Hopkins University, Baltimore, Maryland, USA gfisch@jhu edu}, abstract = {

Magnetic Resonance Imaging (MRI) offers great potential for planning, guiding, monitoring, controlling interventions MR arthrography (MRAr) is the imaging gold standard for assessing small ligament, fibrocartilage injury in joints In contemporary practice, MRAr consists of two consecutive sessions: (1) an interventional session where a needle is driven to the joint space, MR 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 MRAr 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 In preclinical trials, needle insertions have been performed in the joints of porcine, human cadavers using MR image overlay guidance; in all cases, insertions successfully reached the joint space on the first attempt

}, keywords = {Arthrography, Cartilage, Contrast Media, diagnosis, Humans, injuries, instrumentation, Joint Diseases, Ligaments, Magnetic Resonance Imaging, Needles}, doi = {10 1080/10929080601169930}, url = {http://dx doi org/10 1080/10929080601169930}, author = {Gregory Fischer and Anton Degeut and Csaba Csoma and Russell H. Taylor and Laura Fayad and John A Carrino and James Zinreich 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 {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} }