298
Biomedical Signal and Image Processing
FIGURE 15.13 Examples of sections of brain and head and neck scans including 3-D rendering applied to the inner ear. (Courtesy of Philips Medical Systems.)
of the brain that are activated in the collected MR images are then associated to the
performed task. Since any function in all cells including neurons is associated with the
consumption of the oxygen contained in blood, the monitoring of the functional activities of the neurons is in principle equivalent to the detection of oxygen consumption. In
the early 1990s, it was discovered that the oxygenation level of blood will act as a contrast agent in MRI. This discovery forms the basis of fMRI as it is used in present day.
The MRI contrast around blood vessels can be attributed to the state of oxygenation. Specifically, deoxyhemoglobin is more paramagnetic than oxyhemoglobin,
which has almost the same magnetic susceptibility as most tissues. This observation
led to the use of deoxyhemoglobin as a contrast agent for most f MRI methods.
Biomedical Signal and Image Processing
FIGURE 15.13 Examples of sections of brain and head and neck scans including 3-D rendering applied to the inner ear. (Courtesy of Philips Medical Systems.)
of the brain that are activated in the collected MR images are then associated to the
performed task. Since any function in all cells including neurons is associated with the
consumption of the oxygen contained in blood, the monitoring of the functional activities of the neurons is in principle equivalent to the detection of oxygen consumption. In
the early 1990s, it was discovered that the oxygenation level of blood will act as a contrast agent in MRI. This discovery forms the basis of fMRI as it is used in present day.
The MRI contrast around blood vessels can be attributed to the state of oxygenation. Specifically, deoxyhemoglobin is more paramagnetic than oxyhemoglobin,
which has almost the same magnetic susceptibility as most tissues. This observation
led to the use of deoxyhemoglobin as a contrast agent for most f MRI methods.