RT Journal Article SR Electronic T1 Lateral Decubitus Positioning for Cervical Nerve Root Block Using CT Image Guidance Minimizes Effective Radiation Dose and Procedural Time JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 23 OP 28 DO 10.3174/ajnr.A3158 VO 34 IS 1 A1 T.S. Miller A1 K. Fruauff A1 J. Farinhas A1 D. Pasquale A1 C. Romano A1 A.H. Schoenfeld A1 A. Brook YR 2013 UL http://www.ajnr.org/content/34/1/23.abstract AB BACKGROUND AND PURPOSE: Cervical steroid injections are a minimally invasive means of providing pain relief to patients with cervical radiculopathy. CT guidance offers many potential advantages. We developed a technique with the patient in the lateral position with a lateral needle trajectory to minimize the required needle depth from skin to target and a near-vertical needle trajectory. The aim of this study was to analyze the cohort for complications, procedural time, and effective radiation dose. MATERIALS AND METHODS: This was a retrospective evaluation of a single-center patient cohort. PACS images from the procedures were reviewed for needle depth, procedural time, and CTDIvol. An anatomically relevant conversion factor was used to calculate the effective dose. RESULTS: One hundred sixteen cases from 110 patients were identified. The average patient age was 55 years. There were no complications. In 50% of cases, C5–6 was targeted. The average time was 6 minutes, and the average effective radiation dose, 0.51 mSv (0.21–2.56 mSv). Needle-insertion length from the skin to the target was highly correlated with a need for >3 needle repositioning adjustments and scan series (ρ = 0.52, P < .001) and increased procedural time (ρ = 0.42, P < .001). The angle of needle insertion relative to the floor was significantly correlated with an increased number of needle adjustments for depths >25 mm and a longer procedural time (ρ = 0.29, P = .01) but not for depths <25 mm. CONCLUSIONS: The lateral patient position with CT guidance is safe and allows use of a short needle in a vertical trajectory. This reduces the number of needle adjustments and imaging series to provide a short procedural time with a low effective radiation dose from the procedure. CSIcervical epidural steroid injectionsCTDIvolCT dose index volumeDLPdose-length productEDeffective dose