10/3/2016. T1 Anatomical structures are clearly identified, white matter (which has a high fat content) appears bright.

Transcription

1 H2O -2 atoms of Hydrogen, 1 of Oxygen Hydrogen just has one single proton and orbited by one single electron Proton has a magnetic moment similar to the earths magnetic pole Also similar to earth in that is spins The magnetic field produced by the MRI causes the spin to change A 2 nd magnetic field is added which causes the proton to shift again, and change the frequency of the spin, it is at this point that we can see how many protons have been effected by this magnetic field. The energy at this level is very high, when the magnet is turned off and the proton is allowed to return to its resting, low energy state we are able to how many other water molecules are in the system. We can see the difference in tissue types for example grey matter and white matter. Grey matter is effectively hotter compared to white matter. Think of the amount of energy for these high use systems. 1

2 MK1 T1 Anatomical structures are clearly identified, white matter (which has a high fat content) appears bright. CSF appears dark T2 Minimizes the relaxation effects. Pathology is demonstrated due to the fact that most lesions are associated with high water content. 2

3 Slide 4 MK1 Michelle Kelley, 10/3/2016

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5 Diffusion Tensor Imaging (DTI) is a MRI-based neuroimaging technique which makes it possible to visualize the location, orientation, and anisotropy of the brain's white matter tracts. 4

6 Thalamus: relay stations for nerve impulses carrying sensory information into the brain; the thalami receive these sensory inputs as well as inputs from other parts of the brain and determine which of these signals to forward to the cerebral cortex. Midbrain: The midbrain serves important functions in motor movement, particularly movements of the eye, and in auditory and visual processing. Pons: Message station which helps to relay messages from the cortex and the cerebellum. It also plays a key role in sleep and dreaming, where REM sleep occurs. Medula: controls autonomic functions. Motor and sensory neurons from the midbrain and forebrain travel through the medulla. As a part of the brainstem, the medulla oblongata helps in the transferring of messages between various parts of the brain and the spinal cord. Corpus Collosum: Made of Axons, facilitates interhemispheric communication Thalamus: located above the midbrain, relay of sensory and motor signals to the cerebral cortex also regulates consciousness, sleep, and alertness Internal Capsule: carries information past the basal ganglia, separating the caudate nucleus and the thalamus from the putamen and the globus pallidus. The internal capsule contains both ascending and descending axons. External Capsule: Series of white matter fiber tracts. 5

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8 Cingulate: Cingulate: lies above the Corpus Collosum, It receives inputs from the thalamus and the neocortex and projects to the medial temporal lobe. It is part of the limbic system and is involved with emotion formation and processing, learning, and memory. Hippocampus: Used for indexing memories, spacialmemory and navigation. 7

9 The putamen is a round structure located at the base of the forebrain. The putamen and caudate nucleus together form the dorsal striatum. It is also one of the structures that comprises the basal ganglia. The main function of the putamen is to regulate movements and influence various types of learning. It employs GABA and acetylcholine. The putamen also plays a role in degenerative neurological disorders, such as Parkinson's disease. 8

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12 Brain Dissection (Big John) - YouTube#t=1503 Forward to 55:00 for Axial Cut T/ 11

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