The mission of the MMS Group is the development of a novel brain imaging and physiological monitoring modality by combining near-infrared spectroscopy with magnetic resonance imaging and spectroscopy. This will enable the fusion of anatomical information and regional measurements of changes in cerebral tissue oxygenation, oxygen utilization and energy metabolism. The instrumentation and techniques we develop can characterize and monitor the progression and treatment of brain injury in human adults, neonates and animals.
- Current Projects
Our research focuses on the development of computational models of cerebral circulation and metabolism. These models integrate and simulate NIRS and MRS (magnetic resonance spectroscopy) measurements and contribute to the analysis of results from ongoing clinical experiments involving hypoxia ischaemia.
Multimodal Brain Spectroscopy
In order to specifically measure the absorption and scattering of light in tissue over a larger number of wavelengths in the near infrared region we have developed a new time resolved optical spectrometer.
Time resolved spectroscopy is performed by measuring the time-of-flight of photons as they travel through the tissue, if many photon are measured we can generate temporal point spread functions that provide information about the absorption and scattering of light in the tissue.
The system uses a supercontinuum laser and acousto-optic tunable filters allowing us to generate any combination of up to 16 wavelengths in the near infrared region and in a single measurement. The light is coupled to the tissue via two source fibres and detected by four photomultiplier tubes.
Tachtsidis I., Bainbridge A., Faulkner S., Mahoney S., Price D., Thomas D., Cady E., Robertson N., Golay X. "Fusion of near-infrared and magnetic resonance spectroscopy delivers novel multimodal investigation of neonatal hypoxic-ischaemic brain injury.” Brain 2011, Barcelona, Spain, May 2011
Bainbridge A., Tachtsidis I., Faulkner S., Mahoney S., Price D., Thomas D., Cady E., Robertson N., Golay X. “Combined 1H MRS and Near-Infrared Spectroscopy Measurements of Cerebral Blood Volume, Oxygenation, Cytochrome Oxidase, and Intracellular Metabolites During Perinatal Hypoxia-Ischaemia” ISMRM 2011, Montreal, Canada, May 2011
Measuring brain haemodynamics, oxygenation and metabolism during brain functional activation can offer information for brain neuronal activation and provide further insights into neurovascular coupling. We have adopted a multimodal approach that allow us to simultaneously measure: (1) the changes in brain tissue oxy- and deoxy-haemoglobin ([HbO2] [HHb]) and the redox changes in cytochrome-c-oxidase ([ox-redCCO] or [CtOx]), which is a marker of mitochondrial metabolism and (2) the changes in systemic physiology including blood pressure, heart rate and scalp blood flow. We have implemented a plethora of methodologies (SPM, ICA, Wavelets) to explore the crosstalk between systemic changes and NIRS signal changes during frontal lobe activation and have been recently reporting at the presence of false positives in NIRS frontal lobe functional activation studies.
E. Kirilina, A. Jelzow, R. Bruehl, A. Heine, M. Niessing, A. M. Jacobs, B. Ittermann, H. Wabnitz, R. Macdonald, and I. Tachtsidis "Physiological origin of systemic artifacts in functional near infrared spectroscopy as revealed by fMRI." ISMRM 2011, Montreal, Canada, May 2011
Jelzow A,Tachtsidis I,Kirilina E,Niessing M,Bruhl R,Wabnitz H,Heine A,Ittermann B,Macdonald R, “Simultaneous measurement of time-domain fNIRS and physiological signals during a cognitive task.” SPIE-INT SOC OPTICAL ENGINEERING, DIFFUSE OPTICAL IMAGING III, Volume 8088 (2011).
Tharindi Hapuarachchi, Tracy Moroz, Nicola Robertson, Ilias Tachtsidis Modelling blood flow and metabolism in the piglet brain during hypoxia-ischaemia. International Society for Cerebral Blood Flow and Metabolism Conference, Shanghai, China, May 2013
Gemma Bale, Ilias Tachtsidis. Development of a new broadband NIRS systems for measuring brain tissue in neonates.
Luke Dunne, Jem Hebden, Ilias Tachtsidis Development of a new fNIRS multi-wavelength, multi-channel time resolved spectrometer using a supercontinuum laser for measuring brain tissue haemodynamics and metabolism
Tingting Zhu,Jabed F. Ahmed, Ilias Tachtsidis. Monitoring brain oxygenation and metabolism in the adult during frontal lobe functional activation using a novel seven wavelength near-infrared spectrometer. International Society for Cerebral Blood Flow and Metabolism Conference, Spain, May 2011
A.Bainbridge, I. Tachtsidis, S. Faulkner, S. Mahoney, D. Price, D. Thomas, E. Cady, N. Robertson, X. Golay. Combined 1H MRS and near-infrared spectroscopy measurements of cerebral blood volume, oxygenation, cytochrome oxidase, and intracellular metabolites during perinatal hypoxia-ischaemia. International Society for Magnetic Resonance in Medicine Conference, Montreal, Canada, May 2011
Tachtsidis I., Bainbridge A., Faulkner S., Mahoney S., Price D., Thomas D., Cady E., Robertson N., Golay X. Fusion of near-infrared and magnetic resonance spectroscopy delivers novel multimodal investigation of neonatal hypoxic-ischaemic brain injury. International Society for Cerebral Blood Flow and Metabolism Conference, Spain, May 2011