Bone marrow for assessing the marrow cavity of bones, although with low sensitivity and specificity. For example, normal fatty "yellow" marrow in adult long bones is of low density (-30 to -100 Hounsfield units), between subcutaneous fat and soft tissue. Tissue with increased cellular composition, such as normal "red" marrow or cancer cells within the medullary cavity will measure variably higher in density. MRI is more sensitive and specific for assessing bone bone composition. MRI enables assessment of the average molecular composition of soft tissues, and thus provides information regarding the relative fat content of marrow. In adult humans, "yellow" fatty marrow
Tissue (biology) a permanent shape, size and a function is called cellular differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissues. There are 3 types of permanent tissues: A group of cells which are similar in origin; similar in structure and similar in function are called simple permanent tissue. They are of four types: Parenchyma ("para" - 'beside'; "enchyma" - 'tissue') is the bulk of a substance. In plants, it consists of relatively unspecialized living cells with thin cell walls that are usually loosely packed so that intercellular spaces are found between cells of this tissue. These are