title: Use of magnetic resonance imaging in the evaluation of spondylolysis.
abstract: BACKGROUND
  In early studies, magnetic resonance imaging (MRI) had low sensitivity and positive predictive value in the evaluation of the pars interarticularis pathology; however, more recent reports have suggested an expanded role for MRI. The purpose of the present study was to evaluate the effectiveness of MRI in the diagnosis of pars injuries and compare it to computed tomography (CT), which was used as the reference "gold standard" for the detection of fractures.
  
  
  METHODS
  The radiographic and clinic data of 93 adolescents and young adults with a presumptive diagnosis of spondylolysis based upon history and clinic examination were reviewed. Only 26 patients who had MRI and CT images obtained within 30 days of each other were included. All images were reviewed by a fellowship-trained musculoskeletal radiologist and fellowship-trained pediatric orthopaedist.
  
  
  RESULTS
  Overall, 39 individual pars lesions (stress reaction or fracture) were identified. MRI was effective in identifying 36 pars lesions. MRI identified 11 lesions in 9 patients with negative CT. Seven of these lesions were stress reactions (grade 1), whereas 4 were frank fractures. Three pars injuries were noted on CT while the MRI was negative.
  
  
  CONCLUSIONS
  MRI is an effective method (92% sensitivity) for detecting pars injuries. It can detect stress reactions when a fracture is not visible on CT scan, allowing early treatment of these prelysis lesions. The 92% sensitivity of MRI is comparable with that of other diagnostic modalities such as bone scan, with the advantage of no radiation exposure. MRI should be strongly considered as the advanced imaging modality of choice in the evaluation of patients with suspected spondylolysis.
  
  
  METHODS
  Level III-diagnostic study.
authors: *Brooke Army Medical Center, Fort Sam, Houston, TX †Department of Orthopaedic Surgery, Le Bonheur Children's Hospital, University of Tennessee-Campbell Clinic, Memphis, TN.
authors: Jeremy K
authors: JK
authors: Rush
authors: Nelson
authors: N
authors: Astur
authors: Stephanie
authors: S
authors: Scott
authors: Derek M
authors: DM
authors: Kelly
authors: Jeffrey R
authors: JR
authors: Sawyer
authors: William C
authors: WC
authors: Warner
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D015775:Fractures, Stress / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013169:Spondylolysis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D055815:Young Adult