title: Imaging of lumbar spinal surgery complications.
abstract: Lumbar spine surgery for spinal stenosis is a frequently performed procedure and was the fastest growing type of surgery in the US from 1980 to 2000. With increasing surgical invasiveness, postoperative complications also tend to be higher. Cross-sectional imaging techniques (CT and MRI) are more sensitive than radiographs and play an increasingly important role in evaluation of patients with lumbar spine surgery. Their use in patients with metallic implants is somewhat limited by artefacts, which can obscure pathology and decrease accuracy and reader confidence. Metal artefact reduction techniques have been developed, which can significantly improve image quality and enable early detection of postoperative complications. Complications can occur throughout postoperative course. Early complications include hardware displacement, incidental durotomy, postoperative collections-most commonly seroma, and less likely haematoma and/or infection. Incidental durotomy with CSF leak causing intracranial hypotension has characteristic MR brain findings and diagnosis of occult leak sites have been improved with use of dynamic CT myelography. Haematomas, even when compressing the thecal sac, are usually asymptomatic. Early infection, with nonspecific MR findings, can be diagnosed accurately using dual radiotracer studies. Delayed complications include loosening, hardware failure, symptomatic new or recurrent disc herniation, peri-/epidural fibrosis, arachnoiditis, and radiculitis.
  
  
  CONCLUSIONS
  • CT and MRI play an increasingly important role in evaluation of patients with lumbar spine surgery • Complications can occur throughout the postoperative course and early detection is critical • Artefact reduction techniques can improve image quality for early and improved detection of complications.
authors.affiliation: Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar St, New Haven, CT, 06520-8042, USA. ajay.malhotra@yale.edu.
authors.forename: Ajay
authors.identifier: http://orcid.org/0000-0001-9223-6640
authors.initials: A
authors.lastname: Malhotra
authors.affiliation: Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar St, New Haven, CT, 06520-8042, USA. vivekkalramd@gmail.com.
authors.forename: Vivek B
authors.initials: VB
authors.lastname: Kalra
authors.affiliation: Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar St, New Haven, CT, 06520-8042, USA. xiao.wu@yale.edu.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA. ryan.grant@yale.edu.
authors.forename: Ryan
authors.initials: R
authors.lastname: Grant
authors.affiliation: Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar St, New Haven, CT, 06520-8042, USA. richard.bronen@yale.edu.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bronen
authors.affiliation: Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA. khalid.abbed@yale.edu.
authors.forename: Khalid M
authors.initials: KM
authors.lastname: Abbed
keywords: Artefact; CT; Complications; Lumbar spinal surgeries; MR