Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) uses radio waves and a strong magnetic field to provide images of internal organs and tissues. It does not use X-rays. Functional MRI is a procedure that uses MRI to indirectly measure the neural activity occurring in the brain of humans (or other animals). When neurons are active, they consume oxygen. The local response to this oxygen consumption is an increase in blood flow, localized to the regions of increased neural activity.
Functional magnetic resonance imaging (fMRI)
This hemodynamic response occurs after a delay of 1 – 5 seconds, lasts several seconds, and leads to local changes in the relative concentration of oxygenated and deoxygenated haemoglobin. As haemoglobin is diamagnetic when oxygenated but paramagnetic when deoxygenated, the MRI signal of blood is slightly different depending on its level of oxygenation. Using an appropriate sequence (often referred to as Blood Oxygenation Level Dependent or BOLD contrast), MRI is capable of measuring that slight difference in magnetic property. Unlike event-related brain potentials, functional MRI has a poor temporal resolution (in the order of seconds), but a high spatial resolution (in the order of millimetres). Therefore, both acquisition methods are complementary.
Publications
Spatial Patterns of Brain Activity Preferentially Reflecting Transient Pain and Stimulus Intensity
Liang M, Su Q, Mouraux A, Iannetti GD.
Brain regions preferentially responding to transient and iso-intense painful or tactile stimuli
Su Q, Qin W, Yang QQ, Yu CS, Qian TY, Mouraux A, Iannetti GD, Liang M.
The search for pain biomarkers in the human brain
The primary somatosensory cortex and the insula contribute differently to the processing of transient and sustained nociceptive and non-nociceptive somatosensory inputs
Hu L, Zhang L, Chen R, Yu H, Li H, Mouraux A.
Volume of olfactory bulb and depth of olfactory sulcus in 378 consecutive patients with olfactory loss
Hummel T, Urbig A, Huart C, Duprez T, Rombaux P.
Primary Sensory Cortices Contain Distinguishable Spatial Patterns of Activity for Each Sense
Liang M, Mouraux A, Hu L, Iannetti GD.
Bypassing primary sensory cortices - a direct thalamocortical pathway for transmitting salient sensory information
Liang M, Mouraux A, Iannetti GD.
Otolaryngology - Head and Neck Surgery
Prognostic value of olfactory bulb volume measurement for recovery in postinfectious and posttraumatic olfactory loss
Rombaux P, Huart C, Deggouj N, Duprez T, Hummel T.
The depth of the olfactory sulcus is an indicator of congenital anosmia
Huart C, Meusel T, Gerber J, Duprez T, Rombaux P, Hummel T.
Parallel processing of nociceptive and non-nociceptive somatosensory information in the human primary and secondary somatosensory cortices: evidence from dynamic causal modelling of fMRI data
Liang M, Mouraux A, Iannetti GD.
