title: High-resolution magnetic resonance-guided posterior femoral cutaneous nerve blocks.
abstract: OBJECTIVE
  To assess the feasibility, technical success, and effectiveness of high-resolution magnetic resonance (MR)-guided posterior femoral cutaneous nerve (PFCN) blocks.
  
  
  METHODS
  A retrospective analysis of 12 posterior femoral cutaneous nerve blocks in 8 patients [6 (75%) female, 2 (25%) male; mean age, 47 years; range, 42-84 years] with chronic perineal pain suggesting PFCN neuropathy was performed. Procedures were performed with a clinical wide-bore 1.5-T MR imaging system. High-resolution MR imaging was utilized for visualization and targeting of the PFCN. Commercially available, MR-compatible 20-G needles were used for drug delivery. Variables assessed were technical success (defined as injectant surrounding the targeted PFCN on post-intervention MR images) effectiveness, (defined as post-interventional regional anesthesia of the target area innervation downstream from the posterior femoral cutaneous nerve block), rate of complications, and length of procedure time.
  
  
  RESULTS
  MR-guided PFCN injections were technically successful in 12/12 cases (100%) with uniform perineural distribution of the injectant. All blocks were effective and resulted in post-interventional regional anesthesia of the expected areas (12/12, 100%). No complications occurred during the procedure or during follow-up. The average total procedure time was 45 min (30-70) min.
  
  
  CONCLUSIONS
  Our initial results demonstrate that this technique of selective MR-guided PFCN blocks is feasible and suggest high technical success and effectiveness. Larger studies are needed to confirm our initial results.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287, USA. jfritz9@jhmi.edu
authors.forename: Jan
authors.initials: J
authors.lastname: Fritz
authors.forename: Cary
authors.initials: C
authors.lastname: Bizzell
authors.forename: Sudhir
authors.initials: S
authors.lastname: Kathuria
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Flammang
authors.forename: Eric H
authors.initials: EH
authors.lastname: Williams
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Belzberg
authors.forename: John A
authors.initials: JA
authors.lastname: Carrino
authors.forename: Avneesh
authors.initials: A
authors.lastname: Chhabra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D005267:Femoral Nerve / Q000187:drug effects; D006801:Humans; D008160:Lumbosacral Plexus; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D009437:Neuralgia / Q000188:drug therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome