@article {Chowning2006, title = {A preliminary analysis and model of prostate injection distributions}, journal = {The Prostate}, volume = {66}, number = {4}, year = {2006}, month = {Mar}, pages = {344{\textendash}357}, publisher = {Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA schowning@mri jhu edu}, abstract = {

PURPOSE: Understanding the internal dynamics of prostate injections, particularly injection pattern distribution is a key step to developing new therapies for prostate disease that may be best served with a direct injection approach Due to excellent properties involving liquid contrast agents, MRI can be used for targeting, monitoring of injections into organs, tissues MATERIALS AND METHODS: Eleven intraprostatic injections were performed in vivo with canines using a custom transrectal guiding, imaging system for use in a standard 1 5 T MR scanner In addition, 25 injections were performed on excised cadaveric human prostates, using a MedRad Spectris injector system MRI was used to guide the injections, monitor intraparenchymal injection distribution RESULTS: T1, T2-weighted MR images were correlated with histology to produce three-dimensional data sets that can be used to analyze trends in injection patterns This analysis was used to develop strategies for injection prediction such as gadolinium pre-injections, diffusion-weighted imaging guidance In addition, a rough model of prostate injections is described, and a preliminary injection guide is developed that takes into account the individual clinician{\textquoteright}s goals for therapy CONCLUSIONS: MR visualization of injected therapeutic agents allows for prediction, monitoring of drug distributions, possibly improving efficacy, reducing side effects Injection analysis, modeling may be used to assist in optimizing clinical treatments that require or would benefit from focal parenchymal injections into the prostate

}, keywords = {Animals, Antineoplastic Agents, Dogs, drug therapy, Forecasting, Magnetic Resonance Imaging, Male, Models, pharmacokinetics/pharmacology, Prostate, Prostatic Neoplasms, Rectum, Theoretical}, doi = {10 1002/pros 20298}, url = {http://dx doi org/10 1002/pros 20298}, author = {Scott Chowning and Robert Susil and Axel Krieger and Gabor Fichtinger and Whitcomb, Louis L. and Ergin Atalar} } @article {Susil2006, title = {Transrectal prostate biopsy and fiducial marker placement in a standard 1 5T magnetic resonance imaging scanner}, journal = {The Journal of Urology}, volume = {175}, number = {1}, year = {2006}, month = {Jan}, pages = {113{\textendash}120}, publisher = {Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA}, abstract = {

PURPOSE: We investigated the accuracy, feasibility of a system that provides transrectal needle access to the prostate concurrent with 1 5 Tesla MRI which previously has not been possible MATERIALS AND METHODS: In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures),/or prostate biopsy (3 procedures) was performed using local anesthesia RESULTS: Mean procedure duration was 76 minutes, all patients tolerated the intervention well Procedure related adverse events included self-limited hematuria, hematochezia following 3 of 8 procedures (all resolved in less than 1 week) Mean needle placement accuracy was 1 9 mm for the fiducial marker placement studies, 1 8 mm for the biopsy procedures Mean fiducial marker placement accuracy was 4 8 mm, the mean fiducial marker placement accuracy transverse to the needle direction was 2 6 mm All patients who underwent the procedure were able to complete their course of radiotherapy without delay or complication CONCLUSIONS: While studies of clinical usefulness are warranted, transrectal 1 5 T MRI guided prostate biopsy, fiducial marker placement is feasible using this system, providing new opportunities for image guided diagnostic, therapeutic prostate interventions

}, keywords = {Biopsy, Equipment Design, Feasibility Studies, Humans, instrumentation, instrumentation/methods, Magnetic Resonance Imaging, Male, Needle, pathology, Prostate, Prostatic Neoplasms}, doi = {10 1016/S0022-5347(05)00065-0}, url = {http://dx doi org/10 1016/S0022-5347(05)00065-0}, author = {Robert Susil and Cynthia Menard and Axel Krieger and Jonathan Coleman and Kevin Camphausen and Peter Choyke and Gabor Fichtinger and Whitcomb, Louis L. and Norman Coleman and Ergin Atalar} } @article {Krieger2005a, title = {Design of a novel MRI compatible manipulator for image guided prostate interventions}, journal = {IEEE Transactions on Biomedical Engineering}, volume = {52}, number = {2}, year = {2005}, month = {Feb}, pages = {306{\textendash}313}, abstract = {

This paper reports a novel remotely actuated manipulator for access to prostate tissue under magnetic resonance imaging guidance (APT-MRI) device, designed for use in a standard high-field MRI scanner The device provides three-dimensional MRI guided needle placement with millimeter accuracy under physician control Procedures enabled by this device include MRI guided needle biopsy, fiducial marker placements, and therapy delivery Its compact size allows for use in both standard cylindrical, open configuration MRI scanners Preliminary in vivo canine experiments, first clinical trials are reported

}, keywords = {Animals, Biopsy, Computer-Assisted, Dogs, Equipment Design, Equipment Failure Analysis, Feasibility Studies, Imaging, instrumentation/methods, Magnetic Resonance Imaging, Male, Micromanipulation, Needle, pathology/surgery, Prostate, Reproducibility of Results, Robotics, Sensitivity, Specificity, Surgery, Three-Dimensional}, doi = {10 1109/TBME 2004 840497}, url = {http://dx doi org/10 1109/TBME 2004 840497}, author = {Axel Krieger and Robert Susil and Cynthia Menard and Jonathan Coleman and Gabor Fichtinger and Ergin Atalar and Whitcomb, Louis L.} } @article {Susil2003, title = {System for MR image-guided prostate interventions: canine study}, journal = {Radiology}, volume = {228}, number = {3}, year = {2003}, month = {Sep}, pages = {886{\textendash}894}, abstract = {

The purpose of this study was to demonstrate the use of a transrectal system that enables precise magnetic resonance (MR) image guidance, monitoring of prostate interventions The system used a closed-bore 1 5-T MR imaging unit, enables one to take advantage of the higher signal-to-noise ratio achieved with traditional magnet designs, which is crucial for accurate targeting, monitoring of prostate interventions In the first of the four canine studies, reliable needle placement, with all needles placed within 2 mm of the desired target site, was achieved In two other studies, MR imaging was used to monitor distribution of injected contrast agent solution (gadopentetate dimeglumine mixed with trypan blue dye) in, around the prostate, thereby confirming that solution had been delivered to the desired tissue, also detecting faulty injections In the final study, accurate placement, MR imaging of brachytherapy seeds in the prostate were demonstrated The described system provides a flexible platform for a variety of minimally invasive MR image-guided therapeutic, diagnostic prostate interventions

}, keywords = {administration /\&/ dosage, administration /\&/ dosage/diagnostic use, Animals, Brachytherapy, Contrast Media, Dogs, Gadolinium DTPA, Injections, Intralesional, Magnetic Resonance Imaging, Male, methods, Prostate, Prostatic Neoplasms, Radiography, Radiotherapy, Trypan Blue}, doi = {10 1148/radiol 2283020911}, url = {http://dx doi org/10 1148/radiol 2283020911}, author = {Robert Susil and Axel Krieger and Andrew Derbyshire and Attila Tanacs and Whitcomb, Louis L. and Gabor Fichtinger and Ergin Atalar} }