title: MRI features of peripheral traumatic neuromas.
abstract: OBJECTIVE
  To describe the MRI appearance of traumatic neuromas on non-contrast and contrast-enhanced MRI sequences.
  
  
  METHODS
  This IRB-approved, HIPAA-compliant study retrospectively reviewed 13 subjects with 20 neuromas. Two observers reviewed pre-operative MRIs for imaging features of neuroma (size, margin, capsule, signal intensity, heterogeneity, enhancement, neurogenic features and denervation) and the nerve segment distal to the traumatic neuroma. Descriptive statistics were reported. Pearson's correlation was used to examine the relationship between size of neuroma and parent nerve.
  
  
  RESULTS
  Of 20 neuromas, 13 were neuromas-in-continuity and seven were end-bulb neuromas. Neuromas had a mean size of 1.5 cm (range 0.6-4.8 cm), 100 % (20/20) had indistinct margins and 0 % (0/20) had a capsule. Eighty-eight percent (7/8) showed enhancement. All 100 % (20/20) had tail sign; 35 % (7/20) demonstrated discontinuity from the parent nerve. None showed a target sign. There was moderate positive correlation (r = 0.68, p = 0.001) with larger neuromas arising from larger parent nerves. MRI evaluation of the nerve segment distal to the neuroma showed increased size (mean size 0.5 cm ± 0.4 cm) compared to the parent nerve (mean size 0.3 cm ± 0.2 cm).
  
  
  CONCLUSIONS
  Since MRI features of neuromas include enhancement, intravenous contrast medium cannot be used to distinguish neuromas from peripheral nerve sheath tumours. The clinical history of trauma with the lack of a target sign are likely the most useful clues.
  
  
  CONCLUSIONS
  • MRI features of neuromas include enhancement and lack of a target sign. • Contrast material cannot be used to distinguish traumatic neuromas from PNSTs. • Traumatic neuromas can simulate peripheral nerve neoplasms on imaging.
authors.affiliation: Musculoskeletal Radiology Section, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 North Wolfe Street, Baltimore, MD, 21287, USA. sahlawa1@jhmi.edu.
authors.forename: Shivani
authors.initials: S
authors.lastname: Ahlawat
authors.affiliation: Department of Neurosurgery, The Johns Hopkins Hospital, Meyer Bldg, Room 5-181, 600 North Wolfe Street, Baltimore, MD, 21287, USA. abelzbe1@jhmi.edu.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Belzberg
authors.affiliation: Pathology, Oncology and Orthopedic Surgery, The Johns Hopkins Hospital, Weinberg Room 2242, 600 N. Wolfe Street, Sheikh Zayed Tower, Baltimore, MD, 21287, USA. emontgom@jhmi.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Montgomery
authors.affiliation: Department of Radiology and Radiological Science, Musculoskeletal Imaging Section Chief, Department of Orthopedic Surgery, The Johns Hopkins Medical Institutions, 601 North Wolfe Street, Baltimore, MD, 21287, USA. lfayad1@jhmi.edu.|Department of Orthopedic Surgery, The Johns Hopkins Medical Institutions, Baltimore, MD, 21287, USA. lfayad1@jhmi.edu.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Fayad
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009463:Neuroma / Q000473:pathology*; D015588:Observer Variation; D059348:Peripheral Nerve Injuries / Q000473:pathology*; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: End-bulb neuroma; Enhancement; MRI; Neuroma; Neuroma-in-continuity