Magnetic resonance imaging of the lumbar spine after epidural and nerve root injection therapy: evaluation of soft tissue changes

Objective Magnetic resonance imaging (MRI) was performed to evaluate soft tissue changes after nerve root and epidural injections in lumbar spine in patients with radiculopathy. Materials/Methods Patients underwent a multiple-shot injection protocol to nerve root/epidural space. The MRI protocol included T1-weighted, T2-weighted, STIR, and contrast-enhanced, fat-saturated T1-weighted sequences before and after treatment. Results In all treated patients, a diffuse wedge-shaped edema in paravertebral tissues with a slight contrast enhancement was seen. Two small hematomas in the paravertebral muscle were noted. No changes in the epidural space, the abscess, or a lipodystrophy in epidural/nerve root space occurred. Conclusion Normal tissue changes after injection therapy of lumbar radiculopathy include wedge-shaped tissue edema at the injection level. In a minority of patients, small hematomas may occur