Functional 3D Brain Scanning and Matching

Functional brain scanning breaks in one of the links at the chain of figure 2.3. EEG --- electroencephalogram --- and MEG --- magnetoencephalogram --- measures on the very first part of the chain, and thus have the highest temporal resolution. PET (Positron emission tomography) and fMRI breaks in at the lower levels of the chain: The metabolism and the hemodynamics.

Usually in brain mapping using PET and fMRI one talks of 4 different physiological parameters of interest that can be measured [15]:

• CBV --- Cerebral Blood Volume. This method measures the amount of blood in the brain. The unit could be m

• CBF --- Cerebral Blood Flow. This method measures the how much blood gets through the brain. The flow could be measured in m. The imaging of macrovascular (large vessel) and microvascular blood flow is different: microvascular blood flow is intravoxel.

• CMR --- Cerebral Metabolism Rate. This denotes the variety of metabolic parameters one can measure. The one often referred to is the CMRGlu: The glucose metabolism, which is measured in the PET-scanner with the 2-deoxyglucose.

• OC --- Oxygen Consumption. The OC has a quicker response than the hemodynamic response

Before the abbreviation can be put a prefix ''r'', for example rCMRGlu. This stands for regional. if ''rel'' is the prefix it denotes relative .

A functional brain mapping study consists of a group of scans. Rottenberg [63] defines the following words for the grouping of the scans:

• Session. One session is the time a single subject lays in the scanner.

• Run. For fMRI the session is divided into runs. Each run usually consists of 50--100 scans, and with around 10 runs per session.

• Series. For PET the session is divided into series, with each series consisting of around 10 scans.

• Scan. This is the individual image, full volume or slice.

• fMRI
  • Magnetic Resonance
  • Magnetic Resonance Imaging
  • Functional Magnetic Resonance Imaging
• Matching