Investigators


Sendhil VELAN

 
sendhil_velan@sbic.a-star.edu.sg

Growth, Development and Metabolism Programme
Head, MRS & Metabolic Imaging Group

Metabolic  Imaging

Metabolic Imaging group is focused on developing and utilizing advanced imaging approaches including Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) techniques for  clinical applications in  Metabolic disorders.   Imaging techniques allow investigation of human anatomy and localized MR Spectroscopic (MRS) methods  provide detailed information about the metabolic markers including wide range of metabolites for understanding in vivo tissue biochemistry  in normal and pathological tissues.

Singapore Adult Metabolism Study

In this project we aim to investigate the distribution of fat and its functional relationship in insulin-sensitive tissues such as the skeletal muscle, liver and abdominal fat. We will investigate the fat metabolism between the normal weight, overweight and obese adults across Chinese, Malay and Indian ethnicities by Magnetic Resonance Imaging and Spectroscopy (MRI and MRS) approaches. The objective of the study is to determine the relationship between insulin sensitivity and the lipids and also to determine ethnic differences in fat accumulation in a multiethnic cohort of overweight adults.

We are also investigating the fat metabolism of overweight adults before and after weight loss interventions.


Technical Projects

Development of quantitative 2D MRS techniques:   Localized magnetic resonance spectroscopy (MRS) enables detection and quantification of a number of metabolites within a selected volume in vivo. The challenges of in vivo MRS (1H MRS), include low sensitivity and significant overlapping of resonance lines, caused by a narrow chemical shift range at the clinical field strengths.  In this regard, there is a great interest to develop methodology to resolve overlapping metabolites and increase the spectral information obtainable by MRS.  We have implemented wide range of localized multi-dimensional MRS approaches including LCOSY, LCT COSY,  JPRESS, approaches for investigating tissue biochemistry in different body parts. We also have ongoing collaboration with ETH for implementing the ProFit algorithm for achieving quantitation of metabolites using multidimensional MRS techniques.

MRS with Phased Array Coils:  In this project we are currently developing localized 2D MRS (single voxel and multi-voxel) approaches compatible with phased array coil technology.   We will implement algorithms for enhancing the signal to noise ratio and also to reduce acquisition time.

Development of  13C, 31P, 23Na, 19F  MRS techniques :   In this project we are implementing / developing  multinuclear MRS approaches for different body parts for investigating energy metabolism, glycogen  metabolism and carbohydrate metabolism.

Advanced techniques including 1H decoupling and NOE is integrated to increase the SNR of the low natural abundance nuclei.

Whole Brain Spectroscopic Imaging :  In this project we will implement rapid spectroscopic imaging techniques for achieving metabolite maps of different biomarkers in whole brain.

Pre-Clinical Metabolic Imaging: We are also developing MRI/MRS/PET approaches for  rodents at Singapore Bioimaging Consortium to investigate wide range of  animal models with human diseases.   The technology developed on rodent MRI/MRS scanners are being translated to clinical applications.  Currently we have ongoing projects in obesity and diabetes, Liver Cancer, and  Neurodegeneration.

1H-MRS detects differences of carnosine profile in skeletal muscle of rats fed with high-fat and placebo diets. Y. S. K. Terry, A. Pola, B. David Prakash, M. Ghaeminia, and S. S Velan, (To be presented at Proceedings of 19th ISMRM, Montreal, Canada, 2011).

Quantification of Rat brain metabolites by ProFit: Preliminary evaluation of high fat diet induced obesity. B. David Prakash, A. Pola, N. Agarwal, and S. S. Velan (To be presented at Proceedings of 19th ISMRM, Montreal, Canada, 2011).

Changes in foot orientation alters residual dipolar couplings of Creatine and Phosphocreatine in the skeletal muscle of Rats, N. Agarwal, L. D'Silva, and S. S Velan. (To be presented at Proceedings of 19th ISMRM, Montreal, Canada, 2011).

Interethnic differences in fat metabolism of overweight Chinese, Malays and Indians by MRI and MRS approaches. S. A. Sadananthan, M. K-S. Leow, C. M. Khoo, Y. S. Lee, E. S. Tai, and S. S. Velan, (To be presented at Proceedings of 19th ISMRM, Montreal, Canada, 2011).

Evaluation of high fat diet induced obesity in rats by longitudinal MRI and MRS in abdomen, liver and skeletal muscle. A. Pola, S. Tan, T. Y. Keong, Z. Zhou, M. Murabayashi, Y. Nakano, N. Furuyama, N. Hird, and S. S. Velan (To be presented at Proceedings of 19th ISMRM, Montreal, Canada, 2011).

Monitoring glucose in vivo using 2D J PRESS on a 7T MRI/MRS scanner: Implications for neurodegeneration in diabetes Loyola D’Silva, David Bhaskaran, Terry Yew, Nikita Agarwal, David Townsend, George K. Radda, and S. Sendhil Velan, World Molecular Imaging Congress, Sept 8-11, 2010, Kyoto, Japan

Implementation and Validation of Turbo JPress on a 7T MRI/MRS Scanner. Bhaskaran David Prakash, Terry YEW Shze Keong, S. Sendhil Velan. World Molecular Imaging Congress, Sept 8-11, 2010, Kyoto, Japan

Han W, Chuang KH, Chang YT, Olivo M, S. Sendhil Velan, Bhakoo K, Townsend D, Radda GK. Imaging metabolic syndrome, EMBO Mol Med., 2, 196-210, 2010.

S. Sendhil Velan, (2010), "Magnetic Resonance Imaging", in Townsend, D. (ed.), Medical Imaging: Imaging Techniques for Pre-clinical and Clinical Applications, The Biomedical & Life Sciences Collection, Henry Stewart Talks Ltd, London (online at http://hstalks.com/?t=BL1032644-Velan).

Implementation and validation of localized constant-time press on a 7T MRI/MRS scanner Bhaskaran, Loyola, Kishore, Townsend, S. Sendhil Velan. In: Proceedings of 18th ISMRM, Stockholm, Sweden, 2010

Relaxation enhancement by longitudinal multispin orders. Loyola D Silva, S. Sendhil Velan. In: Proceedings of 18th ISMRM, Stockholm, Sweden, 2010

S. Sendhil Velan, Said N, Narasimhan K, Papan C, Bahu A, Vargo JA, Raylman RR, Thomas MA, Rajendran VM, Spencer RG, Alway SE. Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy. Magnetic Resonance Insights, 2008.

Thomas MA, Lipnick S, S. Sendhil Velan, Sherry Liu, Shida Banakar, Nader Binesh, Saadallah Ramadan, Art Ambrosio, Raymond R. Raylman, James Sayre, Nanette DeBruhl and Lawrence Bassett. Investigation of breast cancer using two-dimensional Magnetic Resonance Spectroscopy. Special edition on MRS of Breast Cancer, NMR in Biomedicine, 22, 77-91, 2009.

S. Sendhil Velan, Kumar Pichumani, David Murray, Raymond R. Raylman, Tricia Scott, A. Manivannan, and Larry Halliburton. Magnetic Resonance Spectroscopy with Longitudinal Multispin Orders. Current Analytical Chemistry, 4, 40-54, 2008.

Thomas MA, Lange T, S. Sendhil Velan, Nagarajan R, Raman S, Gomez A, Margolis D, Swart S, Raylman RR, Schulte R, Boesiger P. Two-Dimensional MR Spectroscopy of Human Prostates: Healthy and Prostate Cancer. Special edition on MRS of Prostate Cancer, Magnetic Resonance Materials in Physics, Biology and Medicine (MAGMA), 21, 2008.

S. Sendhil Velan, Said N, Durst C, Frisbee S, Fribee J, Raylman RR, Thomas MA, Rajendran VM, Spencer RG, Alway SE. Distinct Patterns of Fat Metabolism in Skeletal Muscle of Normal Weight, Overweight,and Obese Humans. American Journal of Physiology, Regulatory, Integrative and Comparitive Physiology. 295, R1060-1065, 2008.

Papan C, Boulat B, S. Sendhil Velan, Fraser SE, Jacobs RE. 2D and 3D time-lapse microscopic MRI of Xenopus gastrulation movements utlizing intrinsic tissue-specific contrast. Developmental Dynamics, 236, 494-501, 2007

Papan C, Boulat B, S. Sendhil Velan, Fraser SE, Jacobs RE. Formation of the dorsal marginal zone in Xenopus laevis analyzed by time lapse microscopic magnetic resonance imaging. Developmental Biology, 305, 161-171, 2007.

S. Sendhil Velan, Durst C, Lemieux Sk, Raylman RR, Sridhar R, Spencer RGS, Hobbs GR, Thomas MA. Investigation of muscle lipid metabolism by localized one- and two- dimensional MRS techniques using a clinical 3T MRI/MRS scanner. Journal of Magnetic Resonance Imaging, 25, 192-199, 2007.

S. Sendhil Velan, Lemieux SK, Raylman RR, Boling W, Hobbs GR, Spencer RG, Sridhar R, Kuppusamy P, Thomas MA. Detection of cerebral metabolites by single voxel based PRESS and COSY techniques at 3T. Journal of Magnetic Resonance Imaging, 26, 405 – 409, 2007.

S.Sendhil Velan, Ramamurthy S, Ainala S, Durst C, Lemieux SK, Raylman RR, Spencer RG, Thomas MA, Implementation and validation of localized constant-time correlated spectroscopy (LCT-COSY) on a clinical 3T MRI Scanner for investigation of Muscle metabolism. Journal of Magnetic Resonance Imaging, 26, 410 - 417, 2007.

Raymond R. Raylman, Stan Majewski, S. Sendhil Velan, Susan Lemieux, Brian Kross, Vladimir Popov, Mark F. Smith and Andrew G. Weisenberger. Simultaneous acquisition of magnetic resonance spectroscopy (MRS) data and positron emission tomography (PET) images with a prototype MR-compatible, small animal PET imager. Journal of Magnetic Resonance, 186, 305-310, 2007.

Papan C, Boulat B, S. Sendhil Velan, Fraser SE, Jacobs RE. Time-lapse tracing of mitotic cell divisions in the early Xenopus embryo using microscopic MRI Developmental Dynamics, 235, 3059-3062, 2006.

Raylman RR, Majewski S, Kross B, Lemieux SK, S. Sendhil Velan, Popov V, Proffit J, Smith MF, Weisenberger AG, Wojcik R. Initial tests of a prototype MRI-compatible PET Imager, Nuclear Instruments and Methods in Physics research, Section A, 569,306-309,2006.

R. Raylman, Stan Majewski, Susan K. Lemieux, S. Sendhil Velan, Brian Kross, Vladimir Popov, Mark F. Smith, Andrew G. Weisenberger, Carl Zorn and Gary D.Marano. Simultaneous MRI and PET imaging of a rat brain. Physics in Medicine and Biology, 51, 6371-6379, 2006.

S. Sendhil Velan. Analysis of longitudinal multi-spin orders in strongly coupled spin systems. J. Magn. Reson., 171, 345-352, 2004.

R.A. Moats, S. Sendhil Velan, R. Jacobs, I. Gonzalez-Gomez, D.J. Dobowitz, T. Taga, V. Khankaldyyan, L. Schultz, S. Fraser, M.D. Nelson and W.E. Laug. Micro-MRI at 11.7T of a Murine Brain Tumor Model Using Delayed Contrast Enhancement. Mol. Imaging., 2, 150-158, 2003.

S. Sendhil Velan, P.T. Narasimhan and Russell E. Jacobs. MR Imaging with Phase Encoding of Intermolecular Multiple Quantum Coherences. J. Magn. Reson., 152, 189-194, 2001.

Scott J. Ellis, M. Velayutham, S. Sendhil Velan, Erik F. Petersen, Jay L Zweier, Periannan Kuppusamy and Richard G.S. Spencer. EPR Oxygen Mapping (EPROM) of Engineered Cartilage Grown in a Hollow-Fiber Bioreactor. Magn. Reson. Med., 46, 819-826, 2001.

S. Sendhil Velan, Richard G.S. Spencer, Jay L. Zweier, Periannan Kuppusamy. Electron paramagnetic resonance oxygen mapping (EPROM): Direct visualization of oxygen concentration in tissue. Magn. Reson. Med., 43, 804-809, 2000.

S. Sendhil Velan and N. Chandrakumar. High Resolution NMR measurement of Molecular self-diffusion by Fast Multi-Spin-Echo Diffusion sequences. J. Magn. Reson., Series A 123, 122-125, 1996.

S. Sendhil Velan and N. Chandrakumar. Novel NMR experiments to measure self-diffusion coefficients in solution. Proceedings of the Indian Academy of Sciences (Chemical Sciences) 106, 1661-1669, 1994.  Diamond Jubilee special issue on Magnetic Resonance.

N.R. Jagannathan and S. Sendhil Velan. Therapeutic response of tumors by in vitro proton Nuclear Magnetic Resonance Spectroscopy. Appl. Magn. Reson., 5, 357-367, 1993.

N. Chandrakumar and S. Sendhil Velan. Multiple-Quantum-Single-Quantum NMR Images. J. Magn. Reson., Series A 104, 115-118, 1993.

N. Chandrakumar and S. Sendhil Velan. Separation of Longitudinal Multispin Order by Frequency Cycling. J. Magn. Reson., Series A 104, 363-365, 1993.

S. Sendhil Velan, N.R. Jagannathan, K. Saravanan and B. Nagarajan. Monitoring the therapeutic response of tumors by Nuclear Magnetic Resonance Spectroscopy. Med. Sci. Res., 19, 609-611, 1991.

Dr. Suresh Anand Sadananthan
Research Fellow

Dr. Navin Michael
Research Fellow

Dr. Vijay Nagarajan
Research Fellow