Reliability and Accuracy of MRI Laminar Angle Measurements to Determine Intra-Procedural Contralateral Oblique View Angle for Cervical or Thoracic Interlaminar Epidural Steroid Injections

Abstract

The findings of this study indicate fair inter-rater reliability in manual measurements of laminar angle on axial MRI images. MRI laminar angle measurements do not appear to be highly accurate in determining the appropriate fluoroscopic CLO angle.

The Utility of Determining the Fluoroscopic Contralateral Oblique Angle Measurement During Cervical Interlaminar Epidural Steroid Injections for Use in Repeat Injections

“…At LOR, more definitive realignment was performed if needed and contrast was injected for confirmation. The fluoroscopic angle measurement was calculated appropriately if the patient's true anteroposterior (AP) angle was not zero …”

“…Recently, the contralateral oblique (CLO) fluoroscopic view has gained popularity . Unfortunately, the CLO view at preset recommended angles provides only an estimation of depth because the needle tip, at LOR, often lies anterior to the visualized ventral edge of the lamina, referred to as the ventral interlaminar line (VILL) …”

“…With the CLO view, the anticipated needle depth would be represented by the true CLO angle, the obliquity at which the needle tip aligns with the VILL, and epidural access would be obtained. Unfortunately, attempts to use magnetic resonance imaging (MRI) laminar angle measurements to predetermine the exact angle at which to set the fluoroscope have been unsuccessful …”

Comparison of the contralateral oblique view with the lateral view for mid-thoracic epidural access under fluoroscopic guidance: a randomized controlled trial

“…9 Although the anteroposterior view and LAT view are widely used as standard practice, recent attention has been directed towards using the CLO view for identifying the needle depth during the fluoroscopic-guided interlaminar epidural access. 23 The CLO view appears to be a feasible alternative to the traditional fluoroscopic views for epidural access. 4 7 24 Through scientific geometric analyses of the CLO view, Gill et al suggested that fluoroscopic CLO views at 50° and 45° were proper in the cervical and lumbar regions, respectively, to improve needle tip visualization and provide a consistent landmark when accessing the epidural space.…”

“…The catastrophic risks with the fluoroscopic-guided spine interventions in the cervicothoracic region are intrathecal or intramedullary injection. 23 This could occur through a falsenegative LOR and inappropriate ventral needle advancement. Therefore, for secure mid-TEA using the fluoroscopic CLO view, some safety rules are recommended.…”