The Experts below are selected from a list of 42726 Experts worldwide ranked by ideXlab platform
Rajiv Chopra - One of the best experts on this subject based on the ideXlab platform.
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mr thermometry in the human prostate gland at 3 0t for transurethral Ultrasound Therapy
Journal of Magnetic Resonance Imaging, 2013Co-Authors: Elizabeth Ramsay, Rajiv Chopra, Michael Bronskill, Masoom A Haider, Charles Mougenot, Max O Kohler, Laurence KlotzAbstract:Purpose To investigate the spatial, temporal and temperature resolution of a segmented gradient echo echo-planar imaging (EPI) technique as applied to proton resonance frequency (PRF) shift thermometry at 3 T in the human prostate gland, and to determine appropriate sequence parameters for MRI-controlled transurethral Ultrasound thermal Therapy.
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mr imaging controlled transurethral Ultrasound Therapy for conformal treatment of prostate tissue initial feasibility in humans
Radiology, 2012Co-Authors: Rajiv Chopra, Alexandra J Colquhoun, Mathieu Burtnyk, W A Ndjin, Ilya Kobelevskiy, Aaron Boyes, Kashif Siddiqui, Harry FosterAbstract:MR imaging–controlled transurethral Ultrasound Therapy is feasible in humans and allows for the precise thermal coagulation of prostate tissue by using real-time control with MR thermometry.
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mri guided transurethral Ultrasound Therapy of the prostate gland using real time thermal mapping initial studies
Urology, 2010Co-Authors: Kashif Siddiqui, Rajiv Chopra, Michael Bronskill, Masoom A Haider, Aaron Boyes, Siddharth Vedula, Linda Sugar, Mireia Musquera, Laurence KlotzAbstract:Objective To confirm the correlation between planning and thermal injury of the prostate as determined by magnetic resonance imaging (MRI) and histology in canine and humans treated with transurethral Ultrasound. Material and Methods Canine studies: 2 sets of in vivo studies were performed under general anesthesia in 1.5 T clinical MRI. Nine dogs were treated using single transducer; 8 dogs were treated using urethral applicator with multiple transducers. Rectal cooling was maintained. After initial imaging, a target boundary was selected and high-intensity Ultrasound energy delivered. The spatial temperature distribution was measured continuously every 5 seconds with MR thermometry using the proton-resonant frequency shift method. The goal was to achieve 55 °C at the target boundary. After treatment, the prostate was harvested and fixed with adjoining tissue, including rectum. Temperature maps, anatomical images, and histologic sections were registered to each other and compared. Human studies: To date, 5 patients with localized prostate cancer have been treated immediately before radical prostatectomy. Approximately 30% of the gland volume was targeted. Results A continuous pattern of thermal coagulation was successfully achieved within the target region, with an average spatial precision of 1-2 mm. Radical prostatectomy was routine, with an uncomplicated postoperative course in all patients. The correlation between anatomical, thermal, and histologic images was ≤3 mm. Treatment time was Conclusions Thermal ablation within the prescribed target of the prostate has been successfully demonstrated in canine studies. The treatment is also feasible in humans.
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quantitative analysis of 3 d conformal mri guided transurethral Ultrasound Therapy of the prostate theoretical simulations
International Journal of Hyperthermia, 2009Co-Authors: Mathieu Burtnyk, Rajiv Chopra, Michael BronskillAbstract:Purpose: The capability of MRI-guided transurethral Ultrasound Therapy to produce continuous regions of thermal coagulation that conform to human prostate geometries was evaluated using 3-D anatomical models of prostate cancer patients. Methods: Numerical simulations incorporating acoustic and biothermal modeling and a novel temperature control feedback algorithm were used to evaluate treatment accuracy of a rotating dual-frequency multi-element transducer. Treatments were simulated on twenty anatomical models obtained from the manual segmentation of the prostate and surrounding structures on MR images of prostate cancer patients obtained prior to radical prostatectomy. Results: Regions of thermal coagulation could be accurately shaped to predefined volumes within 1 mm across the vast majority of the prostates. Over- and under-treated volumes remained smaller than 4% of the corresponding prostate volumes which ranged from 14 to 60 cc. Treatment times were typically 30 min and remained below 60 min even for large 60 cc prostates. Heating of the rectal wall remained below 30 min43� C in half of the patient models with only minor, superficial heating in the other cases. The simulated feedback control algorithm adjusted the Ultrasound transducer parameters such that high treatment accuracy was maintained despite variable blood perfusion, changing tissue Ultrasound attenuation, and practical temperature measurement noise and sampling rate. Conclusions: Numerical simulations predict that MRI-guided transurethral Ultrasound Therapy is capable of producing highly accurate volumes of thermal coagulation that conform to human prostate glands.
Marianne J Voogt - One of the best experts on this subject based on the ideXlab platform.
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volumetric feedback ablation of uterine fibroids using magnetic resonance guided high intensity focused Ultrasound Therapy
European Radiology, 2012Co-Authors: Marianne J Voogt, Herve Trillaud, Youngsun Kim, W Th P M Mali, Jorg Barkhausen, Lambertus W Bartels, Roel DeckersAbstract:Objective The purpose of this prospective multicenter study was to assess the safety and technical feasibility of volumetric Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) ablation for treatment of patients with symptomatic uterine fibroids.
Karan P Singh - One of the best experts on this subject based on the ideXlab platform.
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osteopathic manual treatment and Ultrasound Therapy for chronic low back pain a randomized controlled trial
Annals of Family Medicine, 2013Co-Authors: John C Licciardone, Dennis E Minotti, Robert J Gatchel, Cathleen M Kearns, Karan P SinghAbstract:Purpose We studied the efficacy of osteopathic manual treatment (OMT) and Ultrasound Therapy (UST) for chronic low back pain. Methods A randomized, double-blind, sham-controlled, 2 × 2 factorial design was used to study OMT and UST for short-term relief of nonspecific chronic low back pain. The 455 patients were randomized to OMT (n = 230) or sham OMT (n = 225) main effects groups, and to UST (n = 233) or sham UST (n = 222) main effects groups. Six treatment sessions were provided over 8 weeks. Intention-to-treat analysis was performed to measure moderate and substantial improvements in low back pain at week 12 (30% or greater and 50% or greater pain reductions from baseline, respectively). Five secondary outcomes, safety, and treatment adherence were also assessed. Results There was no statistical interaction between OMT and UST. Patients receiving OMT were more likely than patients receiving sham OMT to achieve moderate (response ratio [RR] = 1.38; 95% CI, 1.16-1.64; P Conclusions The OMT regimen met or exceeded the Cochrane Back Review Group criterion for a medium effect size in relieving chronic low back pain. It was safe, parsimonious, and well accepted by patients.
Michael Bronskill - One of the best experts on this subject based on the ideXlab platform.
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mr thermometry in the human prostate gland at 3 0t for transurethral Ultrasound Therapy
Journal of Magnetic Resonance Imaging, 2013Co-Authors: Elizabeth Ramsay, Rajiv Chopra, Michael Bronskill, Masoom A Haider, Charles Mougenot, Max O Kohler, Laurence KlotzAbstract:Purpose To investigate the spatial, temporal and temperature resolution of a segmented gradient echo echo-planar imaging (EPI) technique as applied to proton resonance frequency (PRF) shift thermometry at 3 T in the human prostate gland, and to determine appropriate sequence parameters for MRI-controlled transurethral Ultrasound thermal Therapy.
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mri guided transurethral Ultrasound Therapy of the prostate gland using real time thermal mapping initial studies
Urology, 2010Co-Authors: Kashif Siddiqui, Rajiv Chopra, Michael Bronskill, Masoom A Haider, Aaron Boyes, Siddharth Vedula, Linda Sugar, Mireia Musquera, Laurence KlotzAbstract:Objective To confirm the correlation between planning and thermal injury of the prostate as determined by magnetic resonance imaging (MRI) and histology in canine and humans treated with transurethral Ultrasound. Material and Methods Canine studies: 2 sets of in vivo studies were performed under general anesthesia in 1.5 T clinical MRI. Nine dogs were treated using single transducer; 8 dogs were treated using urethral applicator with multiple transducers. Rectal cooling was maintained. After initial imaging, a target boundary was selected and high-intensity Ultrasound energy delivered. The spatial temperature distribution was measured continuously every 5 seconds with MR thermometry using the proton-resonant frequency shift method. The goal was to achieve 55 °C at the target boundary. After treatment, the prostate was harvested and fixed with adjoining tissue, including rectum. Temperature maps, anatomical images, and histologic sections were registered to each other and compared. Human studies: To date, 5 patients with localized prostate cancer have been treated immediately before radical prostatectomy. Approximately 30% of the gland volume was targeted. Results A continuous pattern of thermal coagulation was successfully achieved within the target region, with an average spatial precision of 1-2 mm. Radical prostatectomy was routine, with an uncomplicated postoperative course in all patients. The correlation between anatomical, thermal, and histologic images was ≤3 mm. Treatment time was Conclusions Thermal ablation within the prescribed target of the prostate has been successfully demonstrated in canine studies. The treatment is also feasible in humans.
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quantitative analysis of 3 d conformal mri guided transurethral Ultrasound Therapy of the prostate theoretical simulations
International Journal of Hyperthermia, 2009Co-Authors: Mathieu Burtnyk, Rajiv Chopra, Michael BronskillAbstract:Purpose: The capability of MRI-guided transurethral Ultrasound Therapy to produce continuous regions of thermal coagulation that conform to human prostate geometries was evaluated using 3-D anatomical models of prostate cancer patients. Methods: Numerical simulations incorporating acoustic and biothermal modeling and a novel temperature control feedback algorithm were used to evaluate treatment accuracy of a rotating dual-frequency multi-element transducer. Treatments were simulated on twenty anatomical models obtained from the manual segmentation of the prostate and surrounding structures on MR images of prostate cancer patients obtained prior to radical prostatectomy. Results: Regions of thermal coagulation could be accurately shaped to predefined volumes within 1 mm across the vast majority of the prostates. Over- and under-treated volumes remained smaller than 4% of the corresponding prostate volumes which ranged from 14 to 60 cc. Treatment times were typically 30 min and remained below 60 min even for large 60 cc prostates. Heating of the rectal wall remained below 30 min43� C in half of the patient models with only minor, superficial heating in the other cases. The simulated feedback control algorithm adjusted the Ultrasound transducer parameters such that high treatment accuracy was maintained despite variable blood perfusion, changing tissue Ultrasound attenuation, and practical temperature measurement noise and sampling rate. Conclusions: Numerical simulations predict that MRI-guided transurethral Ultrasound Therapy is capable of producing highly accurate volumes of thermal coagulation that conform to human prostate glands.
Roel Deckers - One of the best experts on this subject based on the ideXlab platform.
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volumetric feedback ablation of uterine fibroids using magnetic resonance guided high intensity focused Ultrasound Therapy
European Radiology, 2012Co-Authors: Marianne J Voogt, Herve Trillaud, Youngsun Kim, W Th P M Mali, Jorg Barkhausen, Lambertus W Bartels, Roel DeckersAbstract:Objective The purpose of this prospective multicenter study was to assess the safety and technical feasibility of volumetric Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) ablation for treatment of patients with symptomatic uterine fibroids.
