title: Prevalence of stress reaction in the pars interarticularis in pediatric patients with new-onset lower back pain.
abstract: BACKGROUND
  Spondylolysis is a defect of the pars interarticularis and is most commonly encountered in the lower lumbar spine of pediatric patients. Stress reaction of the pars interarticularis was regarded as an early stage of this pathological diagnosis in which no obvious anatomical change is detected. Both SPECT with (99m)Tc MDP and CT of the lumbar spine have been used to evaluate the patients with low back pain. The purpose of this study was to determine the prevalence of stress reaction in pars interarticularis in pediatric patients presenting new-onset back pain using both bone SPECT and CT.
  
  
  METHODS
  The records and images of 63 consecutive pediatric patients (mean age, 13.2 years) with new onset of back pain, who received both (99m)Tc MDP bone scintigraphy with SPECT of the lumbar spine and lumbar thin-slice CT were retrospectively analyzed. The results of bone SPECT and CT were retrospectively compared.
  
  
  RESULTS
  Among the cohort of 63 patients who had both bone SPECT and thin-slice CT of the lumbar spine, there was a total of 56 positive SPECT results indicating stress injuries in the pars interarticularis. Spondylolysis was shown on both bone SPECT and thin-slice CT in 45 patients. In 11 patients, stress reaction was shown. In 7 patients, no abnormality was detected by either SPECT or thin-slice CT.
  
  
  CONCLUSIONS
  Our result showed that a significant portion (19.6%, 11 of 56) of the stress injuries in the pars interarticularis will be CT-negative stress reaction in pediatric patients with new-onset back pain.
authors: Department of Nuclear Medicine, Beijing Friendship Hospital of Capital Medical University, Beijing, China.
authors: Jigang
authors: J
authors: Yang
authors: Sabah
authors: S
authors: Servaes
authors: Kevin
authors: K
authors: Edwards
authors: Hongming
authors: H
authors: Zhuang
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D013169:Spondylolysis / Q000150:complications; D013314:Stress, Mechanical; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed