Raman Chirakal

Raman Chirakal

Associate Professor,
Department of Radiology

B.Sc. (Kerala), M.Sc. (Brock), Ph.D. (McMaster)

Radiopharmaceuticals for Positron Emission Tomography
Contact Information

     My main pursuits are research and development of radiopharmaceuticals for Positron Emission Tomography (PET). PET uses specific molecules labelled with a positron emitting (neutron deficient) isotopes such as 18F, 11C, 13N and 15O. It is an imaging technique that allows the circulatory and metabolic behaviour of small, well-defined volumes of any body tissue to be monitored and measured without trauma in living patients. I am part of a multi-disciplinary health professional group comprising chemists, physicists, medical technologists, nurses and physicians. Our laboratory is equipped with a 11 MeV proton cyclotron and hot cells with remote handling equipment to process large quantities of radioactive materials. My research interests lie in the area of production of short­lived radiopharmaceuticals for the investigation of cerebral metabolism and disorders of human brain, such as schizophrenia and Parkinson's disease, using PET. Particular emphasis is placed on the development of efficient methods for the routine production of 18F-labelled nucleophilic and electrophilic fluorinating agents and the identification and characterization of radionuclidic impurities produced in 18F (t1/2 = 110 min) and 13N (t1/2 = 10 min) targets and their rapid chemical separation.

     Fluorine-18 is also used as a tracer to probe inorganic and organic reaction mechanisms with emphasis towards the production of 18F­labelled imaging agents. Techniques employed for identification and characterization of radiolabelled compounds include radio-HPLC, TLC, autoradiography, mass spectrometry, 1H, 13C, 19F NMR and g-ray spectroscopy.


 This figure shows PET scans of a normal volunteer (left) and a Parkinsonian patient (right) after they were injected with [18F]6-fluoro-L-m-tyrosine. In the figure the person's nose is towards the top and their left is on the right. The pink colour represents the maximum accumulation of 18F, followed by the red, yellow, green and blue.

Larger View

Selected Publications

  1. Raman Chirakal, Neil Vasdev, Gary J. Schrobilgen, Shigeko Amano and Claude Nahmias. "Synthesis of Fluorine-18 Labelled 2-, 5- and 6-Fluoro-L-DOPA and Their in vivo Behaviour in the Human Brain," Radiochimica Acta, (2000) (in Press).

  2. Lindi M. Wahl, Jia Jun Chen, Margo Thompson, Raman Chirakal and Claude Nahmias. "The time course of metabolites in human plasma after [18F]6-fluoro-L-m-tyrosine administration." Eur. J. Nucl. Med., (1999), 26, 1407.

  3. Raman Chirakal, Neil Vasdev, Gary J. Schrobilgen and Claude Nahmias. "Radiochemical and NMR spectroscopic investigation of the solvent effect on the electrophilic elemental fluorination of L-DOPA: synthesis of [18F]5-fluoro-L-DOPA." J. Fluorine Chem., (1999), 99, 87.

  4. R. Chirakal, G. Coates, G. Firnau, G.J. Schrobilgen and C. Nahmias. "Direct Fluorination of Dopamine: 18F-Labelled 6-Fluorodopamine for Imaging Cardiac Sympathetic Innervation in Humans Using PET." Nucl. Med. Biol., (1996), 23, 41.

  5. R. Chirakal, M. Adams, G.J. Schrobilgen, G. Firnau and E.S. Garnett. "Electrophilic 18F from a Siemens 11 MeV Proton-only Cyclotron." Nucl. Med. Biol., (1995), 22, 11.

  6. R. Chirakal, B. McCarry, M. Lonergan, G. Firnau and E.S. Garnett. "Base­Mediated Decomposition of a Mannose Triflate During the Synthesis of 2-18FDG," Appl. Radiat. Isot., (1995) 46, 149.

Contact Information
Mailing Address:
Dr. Raman Chirakal
Department of Radiology
McMaster University
Hamilton, Ont., Canada
L8N 3Z5
 Telephone:
Voice (905) 525-2100, ext. 76893
FAX   (905) 522-2509
Office: HSC-1P10B
Laboratory: HSC-1P10B
E-mail: chiraklr@fhs.mcmaster.ca
 
Chemistry Faculty
Department of Chemistry

Department of Radiology
McMaster Radiochemical Laboratory for PET Radiopharmaceuticals

16feb2000; rc