title: Detection of peripheral nerve pathology: comparison of ultrasound and MRI.
abstract: 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.
authors.affiliation: Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA. zaidmanc@neuro.wustl.edu
authors.forename: Craig M
authors.initials: CM
authors.lastname: Zaidman
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Seelig
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Baker
authors.forename: Susan E
authors.initials: SE
authors.lastname: Mackinnon
authors.forename: Alan
authors.initials: A
authors.lastname: Pestronk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020516:Brachial Plexus Neuropathies / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D010523:Peripheral Nervous System Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods* / Q000592:standards; D055815:Young Adult
references.citation: Scand J Clin Lab Invest. 2008;68(1):77-80
references.pmid: 18224558
references.citation: Clin Imaging. 2008 Mar-Apr;32(2):121-7
references.pmid: 18313576
references.citation: Skeletal Radiol. 1991;20(1):9-14
references.pmid: 1900374
references.citation: J Neuroradiol. 2011 Jul;38(3):141-7
references.pmid: 21232798
references.citation: Muscle Nerve. 2009 Dec;40(6):960-6
references.pmid: 19697380
references.citation: Skeletal Radiol. 2010 Nov;39(11):1061-71
references.pmid: 19730857
references.citation: AJR Am J Roentgenol. 2010 Jun;194(6):1568-74
references.pmid: 20489098
references.citation: Exp Neurol. 2010 May;223(1):238-44
references.pmid: 19879260
references.citation: AJR Am J Roentgenol. 2002 Dec;179(6):1629-31
references.pmid: 12438067
references.citation: Muscle Nerve. 2002 Mar;25(3):314-31
references.pmid: 11870709
references.citation: J Hand Surg Br. 1994 Feb;19(1):55-9
references.pmid: 8169481
references.citation: J Neurosurg. 2011 Jan;114(1):206-11
references.pmid: 20225925
references.citation: Neurol Res. 2012 Jan;34(1):98-103
references.pmid: 22196869
references.citation: Semin Musculoskelet Radiol. 2010 Nov;14(5):463-72
references.pmid: 21072725
references.citation: Skeletal Radiol. 2003 Jul;32(7):375-87
references.pmid: 12851788
references.citation: Skeletal Radiol. 2006 Oct;35(10):745-53
references.pmid: 16775712
references.citation: Pediatr Radiol. 2006 Dec;36(12):1295-9
references.pmid: 17028853
references.citation: Neurol Clin. 2004 Aug;22(3):643-82, vi-vii
references.pmid: 15207879
references.citation: J Neurosurg. 2010 Feb;112(2):362-71
references.pmid: 19663545
references.citation: Skeletal Radiol. 2000 Mar;29(3):142-50
references.pmid: 10794551
references.citation: Eur Radiol. 2007 Jan;17(1):139-49
references.pmid: 16572334
references.citation: Radiographics. 1999 Sep-Oct;19(5):1253-80
references.pmid: 10489179
references.citation: Scand J Plast Reconstr Surg Hand Surg. 2009;43(3):153-9
references.pmid: 19401939
references.citation: Radiographics. 2003 Nov-Dec;23(6):e15
references.pmid: 12939473
references.citation: Radiology. 1988 Apr;167(1):179-82
references.pmid: 3279453
references.citation: Muscle Nerve. 2007 Jun;35(6):796-9
references.pmid: 17309063
references.citation: Eur J Neurol. 2012 Jan;19(1):47-54
references.pmid: 21554493