@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 {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 {Blumenfeld2007, title = {Transperineal prostate biopsy under magnetic resonance image guidance: a needle placement accuracy study}, journal = {Journal of magnetic resonance imaging}, volume = {26}, number = {3}, year = {2007}, month = {Sep}, pages = {688{\textendash}694}, publisher = {Department of Radiology, Brigham, Women{\textquoteright}s Hospital, Harvard Medical School, Boston, Massachusetts, USA}, abstract = {

PURPOSE: To quantify needle placement accuracy of magnetic resonance image (MRI)-guided core needle biopsy of the prostate MATERIALS AND METHODS: A total of 10 biopsies were performed with 18-gauge (G) core biopsy needle via a percutaneous transperineal approach Needle placement error was assessed by comparing the coordinates of preplanned targets with the needle tip measured from the intraprocedural coherent gradient echo images The source of these errors was subsequently investigated by measuring displacement caused by needle deflection, needle susceptibility artifact shift in controlled phantom studies Needle placement error due to misalignment of the needle template guide was also evaluated RESULTS: The mean, standard deviation (SD) of errors in targeted biopsies was 6 5 +/- 3 5 mm Phantom experiments showed significant placement error due to needle deflection with a needle with an asymmetrically beveled tip (3 2-8 7 mm depending on tissue type) but significantly smaller error with a symmetrical bevel (0 6-1 1 mm) Needle susceptibility artifacts observed a shift of 1 6 +/- 0 4 mm from the true needle axis Misalignment of the needle template guide contributed an error of 1 5 +/- 0 3 mm CONCLUSION: Needle placement error was clinically significant in MRI-guided biopsy for diagnosis of prostate cancer Needle placement error due to needle deflection was the most significant cause of error, especially for needles with an asymmetrical bevel

}, keywords = {Aged, Artifacts, Biopsy, Contrast Media, diagnosis/pathology, Humans, Imaging, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, Male, methods, Middle Aged, Needle, Needles, Phantoms, pharmacology, Prostatectomy, Prostatic Neoplasms, Reproducibility of Results, Retrospective Studies}, doi = {10 1002/jmri 21067}, url = {http://dx doi org/10 1002/jmri 21067}, author = {Philip Blumenfeld and Nobuhiko Hata and Simon DiMaio and Kelly Zou and Steven Haker and Gabor Fichtinger and Clare M Tempany} } @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} }