The Reliability of a Grading System for Digital Subtraction Imaging Quality During Cervical Transforaminal Epidural Steroid Injection

• Published in: Pain medicine (Malden, Mass.) Mass.), 2020-11, Vol.21 (11), p.3126-3132
• Main Authors: Binler, Danielle, House, L McLean, Mattie, Ryan, Saltychev, Mikhail, Nagao, Masato, Pekmeczi, Murat, Metz, Lionel, O’Neil, Conor, Shah, Vinil, McCormick, Zachary L
• Format: Article
• Language: English
• Subjects: Bone surgery; Chronic pain; Epidural; Epidural injections; Humans; Injection; Injections; Medical imaging; Methods; Pain; Patient positioning; Radiography, Medical; Rehabilitation; Reproducibility of Results; Spinal cord; Statistical analysis; Steroids; Steroids (Drugs); Visualization
• ISSN: 1526-2375; 1526-4637
• DOI: 10.1093/pm/pnaa032

Abstract Objective Digital subtraction imaging (DSI) decreases the risk of intravascular injection during cervical transforaminal epidural steroid injection (CTFESI); however, sequence acquisition and interpretation are operator-dependent skills. This study tests the reliability of a grading system to determine adequate DSI during CTFESI. Setting Academic tertiary medical center. Methods A grading scheme for adequate DSI quality during CTFESI was created by the study authors based on patient positioning, mask image, and volume of contrast injected. The inter-rater and intrarater reliability values of this grading scheme were tested using 50 DSI images evaluated by three raters during two distinct sessions separated by four weeks. Based on a power analysis, a sample of 50 scans was sufficient to detect significant correlations. Inter-rater reliability was determined by percent agreement between graders for dichotomized categories of “quality of DSI is adequate for safe C-TFESI” vs “quality of DSI is inadequate for safe C-TFESI.” The percentage of agreement was reported, along with Gwet’s agreement coefficient (AC). The intrarater (pre/post) correlation was assessed using Yule’s Q statistics. Results Correlation coefficients were interpreted as follows: 0.00–0.19 “very weak,” 0.20–0.39 “weak,” 0.40–0.59 “moderate,” 0.60–0.79 “strong,” and 0.80–1.00 “very strong.” Inter-rater reliability analyses demonstrated that the patient position category had “very strong” agreement, contrast volume had “strong” agreement, and mask image had “moderate” agreement. The overall inter-rater reliability was “moderate.” All of the raters demonstrated “very strong” intrarater reliability. Conclusions The proposed grading system for adequate-quality DSI during CTFESI showed overall “moderate” and “very strong” inter- and intrarater reliability, respectively. This scheme provides an objective measure of DSI quality for CTFESI. Refinement is needed to improve the reliability of this scheme.