Denervated skeletal muscle: MR imaging. Work in progress.
OBJECTIVE
To evaluate the change in signal intensity of skeletal muscles after denervation and to determine the clinical usefulness of magnetic resonance (MR) imaging in diagnosis of denervation.


METHODS
Denervated skeletal muscles associated with various forms of peripheral neuropathy and spinal radiculopathy were studied with MR imaging in 17 patients.


RESULTS
On T1-weighted images, signal intensity of denervated muscles was normal in 14 patients and high in three. On T2-weighted images, all denervated muscles showed high signal intensity on at least one MR image. High signal intensity in the denervated muscles on T2-weighted images was observed 15 or more days after onset of paralysis. In two patients, signal intensity of denervated muscles returned to normal after relief of paralysis.


CONCLUSIONS
MR imaging is a noninvasive and accurate method for use in diagnosis of denervation and may ultimately eliminate the need for electromyography.
Uetani
M
M
Department of Radiology, Nagasaki University School of Medicine, Japan.
Hayashi
K
K
Matsunaga
N
N
Imamura
K
K
Ito
N
N
D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001132:Arm; D002648:Child; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D005542:Forearm / Q000294:innervation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000473:pathology / Q000502:physiology; D009119:Muscle Contraction; D009132:Muscles / Q000294:innervation* / Q000473:pathology / Q000503:physiopathology; D010243:Paralysis / Q000473:pathology* / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D013997:Time Factors