Ultrasound of tendons and nerves

Abstract

Tendons and nerves represent probably one of the best application of musculoskeletal US due to the high lesion detection rate and accuracy of US combined with its low cost, wide availability, and ease of use. The refinement of high-frequency broadband linear-array transducers, and sensitive color and power Doppler technology, have improved the ability of US to detect fine textural abnormalities of these structures as well as to identify a variety of pathological conditions. Characteristic echotextural patterns, closely resembling the histological ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can assess dislocations, degenerative changes and tendon tears, including intrasubstance tears, longitudinal splits, partial and complete rupture, inflammatory conditions and tendon tumors, as well as postoperative findings. In nerve imaging, US can support clinical and electrophysiological testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Congenital anomalies, nerve tears, and neurogenic tumors can also be diagnosed. Overall, US is an effective technique for imaging tendons and nerves. In most cases, a focused US examination can be performed more rapidly and efficiently than MR imaging.

Ultrasonography and magnetic resonance imaging of ulnar nerve abscess in leprosy

“…On transverse scans, nerves reveal a honeycomb-like appearance with rounded hypoechoic neuronal fascicles in a hyperechoic background. 9 Involved nerves reveal focal thickening (more marked proximal to the medial epicondyle), hypoechoic focal areas (granulomata), peripheral hyperechogenicity (epineural fibrosis), abscesses and increased vascularity on colour-Doppler imaging (in lepra reactions). 2,9 Elias et al 2 have proposed that altered neural anatomy on sonography with preserved electrophysiological tests is highly suggestive of leprosy and may be useful in evaluating asymptomatic household contacts.…”

Schwannoma of the median nerve mimicking carpal tunnel syndrome in a pregnant patient. Case report.

“…This information may change the therapeutic approach. Of note, US has advantages over MRI assessment, being totally safe in pregnancy, showing a higher spatial resolution and allowing the evaluation of long nerve segments in a short time and in a comparative fashion [14,15].…”

Rabbit common calcanean tendon as an animal model: ultrasonographic anatomy and morphometry

“…As components of the CCT rotate along their long axis on the course to calcaneal tuber, preserving the perpendicular angle between each tendon and ultrasound beam is impossible. This may lead to artificial decrease in tendons echogenicity [10,11,21,22] and inconclusive images in transverse plane. It stands in agreement with our results -in transverse images single components (gastrocnemius tendons, superficial digital flexor tendon) of CCT could not be precisely identified.…”

“…A valid animal model needs to consistently replicate the clinical, histopathological and functional characteristics of tendon disorders [19] along with being accessible to assess with imaging techniques commonly used in human and equine medicine for eventual comparison. Considering that the tissue specimens of injured tendons are not available for histopathological examination in clinical practice, the ultrasound and magnetic resonance imaging are the gold standard in diagnosing tendon disorders, with ultrasonography being cost-effective, non-invasive and generally accessible [10,11,21]. Several animal models are currently used in tendinopathy research including laboratory animals, like rabbits [5,23,25,26,29,33], rats [9,15,17] and mice [8] as well as companion animals, like horses [2,3,31] and dogs [20].…”