** Neurology and MRI's for Dummies **

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Mastoiditis: is a bacterial infection of the mastoid air cells (small, air-filled cavities located in the mastoid process, which is the bulge in the skull behind the ear).

 

Brain abscess: (or cerebral abscess) caused by inflammation and collection of infected material coming from local (ear infection, infection of paranasal sinuses, infection of the mastoid air cells of the temporal bone, epidural abscess) or remote (lung, heart, kidney etc.) infectious sources within the brain tissue.

 

Ring enhancing tumor: the inflammation and the concomitant dead brain tissue are surrounded with a capsule, which gives the lesion the famous ring-enhancing appearance.

 

Vasogenic edema: "brain swelling"

 

Subependymal (SUB-ep-EN-di-mal): Below the ependyma (the membrane that lines the ventricles of the brain and the central canal of the spinal cord).

 

Right temporoparietal lesion: "tumor near right temple."

 

Significantly progressed: "gotten much bigger"

 

Internal & external capsule: "the white matter that connects upper brain to the lower brain and the spine."

 

Inferiorly: "downwards"

 

Anteriorly: "frontwards"

 

Posterior: The back or behind, as opposed to the anterior.

 

Occipital lobe: devoted to visual processing. The most caudal (The furthest section of the brain from the eyes, back of head) portion of the cerebral cortex.

 

Subcortical and deep white matter: "lower brain areas."

 

Right temporal lobe: "brain near right temple."

 

Vascular: means "related to blood vessels".

 

Cerebrospinal fluid: (CSF) produced by the choroid plexus which is formed by specialized ependymal cells. It is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex).

 

Lateral ventricle, temporal horn: located in the deep temporal lobe. Facilitates CSF circulation throughout the temporal lobe.

 

Ependymal cells: A cell lining the central canal of the spinal cord (those of pyramidal shape) or one of the brain ventricles (those of cuboidal shape).

 

 

Heterogenous: Consisting of dissimilar elements or parts; not homogeneous.

 

Ischemia: (Greek, isch- is restriction, hema or haema is blood) is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue

 

 

Multiplanar: Type of MRI examination where the data obtained during the scan can be re-processed to make slices in any plane (cross-sectional, lengthways, angled etc.)

 

PERIVENTRICULAR WHITE MATTER:

PVM refers to white matter that is immediately to the side of the two lateral (side) ventricles of the brain. The lateral ventricles are two curved openings (shaped like a horseshoe) located deep within the top section of the brain. White matter is a group of white nerve fibers that conduct nerve impulses quickly. White matter is important for muscle movements. PVM comes from the Greek word "peri" meaning "around," the Latin word "venter" meaning "belly," the Proto-Indo-European word "kwintos" meaning "bright," and the Latin word "materies" meaning "substance." Put the words together and you have "bright substance around (the) belly."

 

T1 and T2 for dummies:

(Used in MRI's) all tissues have a T1 and a T2 value; these values are defined by the way the protons in the tissues respond to the MRI machine signals. One of these, T1 (T1 Time), is a measure of the tissues' responses to the signal; the other, T2 (T2 Time), is the measure of the tissues' relaxation speed after stimulation by the MRI machine. So, basically, the machine makes a signal, the tissues respond, the device records the response of the tissues to the signal.

 

Contrast: the relative difference of signal intensities in two adjacent regions of an image. Due to the T1 and T2 relaxation properties, differentiation between various tissues in the body is possible.

 

Flair: Fluid-Attenuated Inversion Recovery (MRI sequence). Lesions that are normally covered by bright fluid signals using conventional T2 contrast are made visible by the dark fluid technique. It is an important technique for the differentiation of brain and spine lesions.