My research is concentrated on the development of image-guided therapies. In particular, I have focused on the biomedical applications of HIFU (High-Intensity Focused Ultrasound). Ultrasound is an attractive form of energy for therapeutic use since it can be transmitted through the body from external transducers, can be focused to very localized regions of a few mm, and can be generated from devices of multiple geometries ranging from large focused transducers to catheter based devices. A unique set of capabilities arises when this technology is combined with magnetic resonance imaging (MRI). The ultrasound technology is able to non-invasively deliver energy within the body for applications such as mild heating or tissue ablation, and MRI is able to acquire images of the temperature distribution in the heated tissues during heating. Since the relationship between temperature, time and cell kill is well established, this creates a powerful closed loop method for treating soft tissues.
The other emerging application of HIFU is to potentiate or enable targeted delivery of agents within the body. Ultrasound can be used to trigger release from temperature sensitive liposomes, or to non-invasively open the blood brain barrier. These capabilities open up many possibilities for targeted drug delivery in the brain and other organs with pre-existing vascular barriers (retina, testicles, placenta, etc).
My research has a preclinical component focused on novel applications of HIFU, and a translational component aimed at evaluating established HIFU approaches in patients.
- Mcmaster University (1996), Physics
- Graduate School
- University of Toronto (2002), Biophysics
- Enhancement of radiation and chemotherapy using MRI-controlled HIFU
- Image-guided drug delivery to the brain using ultrasound energy
- Non-invasive tissue ablation and hyperthermia using high-intensity focused Ultrasound (HIFU)
- MRI-controlled transurethral ultrasound therapy for localised prostate cancer.
- Chopra R, Burtnyk M, N'djin WA, Bronskill M Int J Hyperthermia 2010 26 8 804-21
- Antibodies targeted to the brain with image-guided focused ultrasound reduces amyloid-beta plaque load in the TgCRND8 mouse model of Alzheimer's disease.
- Jordão JF, Ayala-Grosso CA, Markham K, Huang Y, Chopra R, McLaurin J, Hynynen K, Aubert I PLoS ONE 2010 5 5 e10549
- In vivo MR elastography of the prostate gland using a transurethral actuator.
- Chopra R, Arani A, Huang Y, Musquera M, Wachsmuth J, Bronskill M, Plewes D Magn Reson Med 2009 Sep 62 3 665-71
- MR acoustic radiation force imaging: in vivo comparison to ultrasound motion tracking.
- Huang Y, Curiel L, Kukic A, Plewes DB, Chopra R, Hynynen K Med Phys 2009 Jun 36 6 2016-20
- An MRI-compatible system for focused ultrasound experiments in small animal models.
- Chopra R, Curiel L, Staruch R, Morrison L, Hynynen K Med Phys 2009 May 36 5 1867-74
- Analysis of the spatial and temporal accuracy of heating in the prostate gland using transurethral ultrasound therapy and active MR temperature feedback.
- Chopra R, Tang K, Burtnyk M, Boyes A, Sugar L, Appu S, Klotz L, Bronskill M Phys Med Biol 2009 May 54 9 2615-33
- Quantitative analysis of 3-D conformal MRI-guided transurethral ultrasound therapy of the prostate: theoretical simulations.
- Burtnyk M, Chopra R, Bronskill MJ Int J Hyperthermia 2009 Mar 25 2 116-31
- In vivo monitoring of focused ultrasound surgery using local harmonic motion.
- Curiel L, Chopra R, Hynynen K Ultrasound Med Biol 2009 Jan 35 1 65-78
- Progress in multimodality imaging: truly simultaneous ultrasound and magnetic resonance imaging.
- Curiel L, Chopra R, Hynynen K IEEE Trans Med Imaging 2007 Dec 26 12 1740-6
- Prostate tissue analysis immediately following magnetic resonance imaging guided transurethral ultrasound thermal therapy.
- Boyes A, Tang K, Yaffe M, Sugar L, Chopra R, Bronskill M J. Urol. 2007 Sep 178 3 Pt 1 1080-5
Honors & Awards
- CPRIT Rising Star Award