Muscle activation produces increases in magnetic resonance (T2) signal intensity leading to recruitment images that demonstrate spatial patterns and intensity of muscle activation. These T2 activation maps are useful for visualizing and quantifying various aspects of muscle function. Activity-dependent changes in T2 result from an increase in the T2 relaxation time of muscle water. The current state of investigation indicates that the mechanism of increased T2 results from osmotically driven shifts of muscle water that increase the volume of the intracellular space and from intracellular acidification resulting from the end products of metabolism. Although the spatial resolution of magnetic resonance imaging is still insufficient to map territories of individual motor units, it is possible to demonstrate nonuniform activation-between subregions or compartments of muscle. Taken together, the attributes of the T2 mapping technique hold great potential for demonstrating aberrant muscle activation patterns in pathology and positive adaptation to exercise or rehabilitative intervention.
|Original language||English (US)|
|Number of pages||9|
|Journal||Seminars in Musculoskeletal Radiology|
|State||Published - Dec 1 2003|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging