Devoted to diagnostic and interventional spine imaging and therapeutics


Value of 3-Dimentional MR Lumbosacral Radiculography in Diagnosis of Symptomatic Chemical radiculitis 2011

General Spine

Woo Mok, Byun, M.D
Han Won, Jang, M.D, Non ASSR Member



To investigate significance of 3-dimentional MR radiculography in diagnosis of symptomatic chemical radiculitis.

Methods & Materials

The study population consisted of 17 patients (age range, 51-72 years; mean ages, 62 years) with annular tear. All patients with annular tear had pain referred to leg. Symptomatic chemical radiculitis was confirmed with provocative CT discography and/or provocative selective nerve root block for agreement of sides and levels. Conventional MR imagings and 3D coronal fast-field echo (FFF) sequence with selective water excitation by using the principles of the selective excitation technique (Proset imaging) were acquired. Morphologic change of ipsilateral symptomatic nerve root caused by chemical radiculitis was compared with those of contralateral nerve root on 3-D MR lumbosacral radiculography. The relationship between morphologic change of symptomatic nerve root caused by chemical radiculitis on 3-D MR lumbosacral radiculography and provocative discography and/or selective nerve root block for confirmation of the radiculopathy was analyzed.


Pain reproduction at contrast leak level during discography (n=4) and selective nerve root injection (n=13) showed concordant pain in all patients. All perianular enhancement caused by chemical radiculitis demonstrated a thick and linear enhancement along margins of annular tears on contrast enhanced axial T1-weighted images with fat suppression. All patients with symptomatic chemical radiculitis showed nerve root swelling in ipsilateral levels and sides on 3-D MR radiculography. The most common nerve root lesion caused by the chemical radiculitis was L5 nerve root (n=13). Swelling of only the exit nerve root was observed in 7 cases. Swelling of the entire segments of the nerve root was seen in 9 cases. One case showed swelling of the transverse nerve root. The most common segments of the nerve root swelling was the exit nerve root (n=16). We suggest that there is relationship between inflammatory perianular enhancement at the extraforaminal or foraminal zones and swelling of the exit nerve root. All patients with symptomatic chemical radiculitis were treated with selective nerve root block. Clinical symptoms were improved within several weeks after selective nerve root block.


All patients with radiculopathy caused by chemical radiculitis showed nerve root swelling on 3-D MR radiculography. We believe that in cases without mechanical nerve root compression caused by disc herniation or stenosis in lumbar spine, nerve root swelling on 3-D MR radiculography in patients with radiculopathy may be relevant in the diagnosis of symptomatic chemical radiculitis.

References/Financial Disclosures

1. Marshall LL, Trethewie ER, Curtain CC. Chemical radiculitis. A clinical, physiological and immunological study. Clin Orthop Relat Res 1977:61-7. 2. Muramoto T, Atsuta Y, Iwahara T, et al. The action of prostaglandin E2 and triamcinolone acetonide on the firing activity of lumbar nerve roots. Int Orthop 1997;21:172-5. 3. Peng B, Wu W, Li Z, et al. Chemical radiculitis. Pain 2007;127:11-6. 4. Byun WM, Ahn SH, Ahn MW. Significance of perianular enhancement associated with anular tears on magnetic resonance imagings in diagnosis of radiculopathy. Spine (Phila Pa 1976) 2008;33:2440-3. 5. Olmarker K, Rydevik B, Nordborg C. Autologous nucleus pulposus induces neurophysiologic and histologic changes in porcine cauda equina nerve roots. Spine (Phila Pa 1976) 1993;18:1425-32. 6. Otani K, Arai I, Mao GP, et al. Nucleus pulposus-induced nerve root injury: relationship between blood flow and motor nerve conduction velocity. Neurosurgery 1999;45:614-9; discussion 9-20. 7. Habtemariam A, Virri J, Gronblad M, et al. Inflammatory cells in full-thickness anulus injury in pigs. An experimental disc herniation animal model. Spine (Phila Pa 1976) 1998;23:524-9. 8. Saal JS, Franson RC, Dobrow R, et al. High levels of inflammatory phospholipase A2 activity in lumbar disc herniations. Spine (Phila Pa 1976) 1990;15:674-8. 9. Chen C, Cavanaugh JM, Ozaktay AC, et al. Effects of phospholipase A2 on lumbar nerve root structure and function. Spine (Phila Pa 1976) 1997;22:1057-64. 10. Peng B, Hou S, Wu W, et al. The pathogenesis and clinical significance of a high-intensity zone (HIZ) of lumbar intervertebral disc on MR imaging in the patient with discogenic low back pain. Eur Spine J 2006;15:583-7. 11. Lim CH, Jee WH, Son BC, et al. Discogenic lumbar pain: association with MR imaging and CT discography. Eur J Radiol 2005;54:431-7. 12. Kim SB, Jang JS, Lee SH. Morphologic Changes of L5 Root at Coronal Source Images of MR Myelography in Cases of Foraminal or Extraforaminal Compression. J Korean Neurosurg Soc 2009;46:11-5. 13. Shen J, Wang HY, Chen JY, et al. Morphologic analysis of normal human lumbar dorsal root ganglion by 3D MR imaging. AJNR Am J Neuroradiol 2006;27:2098-103. Figure legends Fig.1. Forty years old female with left buttock and lateral thigh pain. T2-weighted images (A) show subtle intermediate signal intensity and nerve root (arrow) in the far lateral to the left neural foramen at L5-S1. Note anular tear along left lateral margin of the disc. There is abnormal enhancement at the perianular extraforaminal portion (arrow) due to the fibrovascular and granulation tissue in L5-S1 on contrast enhanced T1-weighted image with fat suppression (B). Diffuse swelling of left L5 nerve root (arrows) is demonstrated on 3-D MR radiculography (C). Pain reproduction at this level during selective nerve root injection (D) showed concordant pain (prone position). After selective nerve root block at L5 nerve root, clinical symptoms are completely improved.