Detection of peripheral nerve pathology: comparison of ultrasound and MRI

Neurology. 2013 Apr 30;80(18):1634-40. doi: 10.1212/WNL.0b013e3182904f3f. Epub 2013 Apr 3.


Objective: To compare accuracy of ultrasound and MRI for detecting focal peripheral nerve pathology, excluding idiopathic carpal or cubital tunnel syndromes.

Methods: We performed a retrospective review of patients referred for neuromuscular ultrasound to identify patients who had ultrasound and MRI of the same limb for suspected brachial plexopathy or mononeuropathies, excluding carpal/cubital tunnel syndromes. Ultrasound and MRI results were compared to diagnoses determined by surgical or, if not performed, clinical/electrodiagnostic evaluation.

Results: We identified 53 patients who had both ultrasound and MRI of whom 46 (87%) had nerve pathology diagnosed by surgical (n = 39) or clinical/electrodiagnostic (n = 14) evaluation. Ultrasound detected the diagnosed nerve pathology (true positive) more often than MRI (43/46 vs 31/46, p < 0.001). Nerve pathology was correctly excluded (true negative) with equal frequency by MRI and ultrasound (both 6/7). In 25% (13/53), ultrasound was accurate (true positive or true negative) when MRI was not. These pathologies were typically (10/13) long (>2 cm) and only occasionally (2/13) outside the MRI field of view. MRI missed multifocal pathology identified with ultrasound in 6 of 7 patients, often (5/7) because pathology was outside the MRI field of view.

Conclusions: Imaging frequently detects peripheral nerve pathology and contributes to the differential diagnosis in patients with mononeuropathies and brachial plexopathies. Ultrasound is more sensitive than MRI (93% vs 67%), has equivalent specificity (86%), and better identifies multifocal lesions than MRI. In sonographically accessible regions ultrasound is the preferred initial imaging modality for anatomic evaluation of suspected peripheral nervous system lesions.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brachial Plexus Neuropathies / diagnostic imaging*
  • Brachial Plexus Neuropathies / pathology*
  • Child
  • Child, Preschool
  • Databases, Factual
  • Female
  • Humans
  • Infant
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Imaging / standards
  • Male
  • Middle Aged
  • Peripheral Nervous System Diseases / diagnostic imaging*
  • Peripheral Nervous System Diseases / pathology*
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Ultrasonography / methods*
  • Ultrasonography / standards
  • Young Adult