title: Simple oblique lumbar magnetic resonance imaging technique and its diagnostic value for extraforaminal disc herniation.
abstract: METHODS
  Prospective study evaluating the oblique lumbar magnetic resonance imaging (MRI).
  
  
  OBJECTIVE
  To present the technique of oblique lumbar MRI and assess the clinical efficacy of this technique for diagnosis of extraforaminal disc herniation.
  
  
  BACKGROUND
  Herniated lumbar discs are traditionally diagnosed using conventional lumbar axial and sagittal MRI. However, conventional lumbar MRI might not reveal nerve root compression in the extraforaminal area. Oblique lumbar MRI can provide clear visualization of the dorsal root ganglion and lumbar nerve root in the foraminal and extraforaminal areas.
  
  
  METHODS
  Ten patients diagnosed with extraforaminal disc herniations underwent bilateral oblique lumbar MRIs before surgery (turbo spin-echo T2-weighted sequence). We compared the side with symptomatic extraforaminal disc herniation to the asymptomatic contralateral side.
  
  
  RESULTS
  Oblique lumbar MRI succeeded in depicting pedicles, dorsal root ganglions, and lumbar nerve roots of the foraminal and extraforaminal areas. In 9 of 10 patients (90.0%), nerve root compression by the herniated disc in the extraforaminal area was clearly demonstrated when compared with the asymptomatic contralateral side (P < 0.05). In 1 patient with scoliosis and spinal stenosis, oblique MRI could not clearly display foraminal or extraforaminal anatomy due to spinal deformity.
  
  
  CONCLUSIONS
  In light of this data, we suggest that oblique lumbar MRI can precisely demonstrate nerve roots in foraminal and extraforaminal areas. This technique is a simple and useful diagnostic tool for extraforaminal lumbar disc herniations.
authors.affiliation: Department of Neurosurgery, Chunchon Sacred Heart Hospital, College of Medicine, Hallym University, Chunchon, Korea. youmans@empal.com
authors.forename: Dong Hwa
authors.initials: DH
authors.lastname: Heo
authors.forename: Myeong Sub
authors.initials: MS
authors.lastname: Lee
authors.forename: Seung Hun
authors.initials: SH
authors.lastname: Sheen
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Cho
authors.forename: Yong Jun
authors.initials: YJ
authors.lastname: Cho
authors.forename: Sae Moon
authors.initials: SM
authors.lastname: Oh
mesh_terms: D000368:Aged; D019299:Decompression, Surgical / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D005727:Ganglia, Spinal / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007231:Infant, Newborn; D007403:Intervertebral Disc / Q000473:pathology* / Q000503:physiopathology; D007405:Intervertebral Disc Displacement / Q000175:diagnosis* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D011843:Radiculopathy / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012680:Sensitivity and Specificity; D013126:Spinal Nerve Roots / Q000473:pathology* / Q000503:physiopathology; D021801:Zygapophyseal Joint / Q000473:pathology / Q000503:physiopathology