title: Reducing patient radiation dose during CT-guided procedures: demonstration in spinal injections for pain.
abstract: OBJECTIVE
  CT guidance may improve precision for diagnostic and therapeutic spinal injections, but it can increase patient radiation dose. This study examined the impact of reducing tube current on patient radiation exposure and the technical success for these procedures, by using axial acquisitions for short scan lengths and eliminating nonessential imaging.
  
  
  METHODS
  Our institutional review board approved retrospective analysis of records from 100 consecutive outpatients undergoing spinal injections for pain before and after the CT protocol modification to reduce radiation dose. Data collected included patient age and sex, response to injection, number of sites and spinal levels treated, injection type, performing physician, CT acquisition method, number of imaging series, tube current, scan length, and DLP.
  
  
  RESULTS
  Image contrast was reduced with the low-dose protocol, but this did not affect technical success or immediate pain relief. Mean DLP for all procedures decreased from 1458 ± 1022 to 199 ± 101 mGy · cm (P < .001). The range of radiologist-dependent DLP per procedure also was reduced significantly with the modified protocol. Selective nerve root blocks, lumbar injections, multiple injection sites, and the lack of prior imaging were each associated with a slightly higher DLP (<50 mGy · cm).
  
  
  CONCLUSIONS
  Radiation to patients undergoing CT-guided spinal injections can be decreased significantly without affecting outcome by reducing tube current, using axial acquisitions for short scan lengths, and eliminating nonessential imaging guidance. These measures also decrease variability in radiation doses between different practitioners and should be useful for other CT-guided procedures in radiology.
authors.affiliation: Neuroradiology Division, Department of Radiology and Biomedical Imaging, University of California, San Francisco, 94143-0628, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Shepherd
authors.forename: C P
authors.initials: CP
authors.lastname: Hess
authors.forename: C T
authors.initials: CT
authors.lastname: Chin
authors.forename: R
authors.initials: R
authors.lastname: Gould
authors.forename: W P
authors.initials: WP
authors.lastname: Dillon
mesh_terms: D000328:Adult; D000700:Analgesics / Q000008:administration & dosage*; D001822:Body Burden; D005260:Female; D006801:Humans; D007278:Injections, Spinal / Q000379:methods; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000150:complications / Q000188:drug therapy*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods*; D015641:Radiography, Interventional / Q000009:adverse effects / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000379:methods*; D055815:Young Adult
chemical_list: D000700:Analgesics