Radiological evaluation of spinal canal, dural sac, epidural fat and superior articular process in diagnosis of lumbar spinal stenosis

Abstract

Aim: The aim of our study; to investigate the location of hypertrophy in the epidural adipose tissue in the lumbar spinal stenosis clinic, to compare the area measurements of the spinal canal and dural sac in patients with a preliminary diagnosis of lumbar spinal stenosis or radiculopathy, and to determine the place of the superior articular process area measurement in the diagnosis of spinal stenosis. Material and Method: 180 patients aged 50-69 years who underwent Lumbar Magnetic Resonance Imaging were divided into two groups according to the prediagnosis of lumbar spinal stenosis or radiculopathy and retrospectively analyzed. Spinal canal, dural sac, epidural fat, and superior articular process areas were measured. Statistical relationships of the findings were investigated. Results: There was no difference between the stenosis groups of these patients in terms of age and gender (respectively p=0.078; p=0.564). There is a significant difference in terms of the spinal canal, dural sac, superior articular process, and epidural fat widths between spinal stenosis and radiculopathy (p<0.001; p<0.001; p<0.001; p=0.033, respectively). Superior articular process, spinal canal, dural sac, and epidural fat cross-sectional areas were each found significant for their use as a diagnostic test for diagnosing lumbar spinal stenosis (p<0.001; p<0.001; p<0.001; p=0.034, respectively). Conclusion: Spinal stenosis is a problem that greatly affects the quality of life of patients. Measuring only the width of the spinal bony canal does not provide sufficient information in the diagnosis of spinal stenosis. In our study, hypertrophy of the superior articular process was the strongest finding in the diagnosis of lumbar spinal stenosis. Hypertrophy of epidural adipose tissue has also been shown to be a risk factor for lumbar spinal stenosis. In radiological evaluations, other structures that narrow the canal should also be carefully examined.

Keywords

• Spinal stenosis
• Dural stenosis
• Epidural fat

References

1. Kalichman L, Cole R, Kim DH, et al. Spinal stenosis prevalence and association with symptoms: the Framingham Study. Spine J 2009; 7: 545–50.
2. Lim TH, Choi SI, Cho HR, et al. Optimal cut-off value of the superior articular process area as a morphological parameter to predict lumbar foraminal stenosis. Pain Res Manag 2017; 7: 7914836.
3. Amundsen T, Weber H, Lilleås F, et al. Lumbar spinal stenosis. Clinical and radiologic features Spine 1995; 20: 1178-86.
4. Ogikubo O, Forsberg L, Hansson T. The relationship between the cross-sectional area of the cauda equina and the preoperative symptoms in central lumbar spinal stenosis. Spine 2007; 32: 1423–8.
5. Schizas C, Theumann N, Burn A, et al. Qualitative grading of severity of lumbar spinal stenosis based on the morphology of the dural sac on magnetic resonance images. Spine 2010; 35: 1919–24.
6. Sirvanci M, Bhatia M, Ganiyusufoglu KA, et al. Degenerative lumbar spinal stenosis: correlation with Oswestry Disability Index and MR imaging. Eur Spine J 2008; 17: 679–85.
7. Deyo RA, Gray DT, Kreuter W, et al. United States trends in lumbar fusion surgery for degenerative conditions, Spine 2005; 30: 1441–5.
8. Yoshihara H, Yoneoka D. National trends in the surgical treatment for lumbar degenerative disc disease: United States, 2000 to 2009. Spine J 2015; 15: 265–71.

9. Wei FL, Zhou CP, Liu R, et al. Management for lumbar spinal stenosis: a network meta-analysis and systematic review Int. J Surg 2020; 85: 19-28.
10. Panda SK, Arora G, Mohanty BB, et al. Evaluation of canal stenosis of herniated lumbar disc and its correlation to anterior-posterior diameter with magnetic resonance imaging morphometry. Int J Health Allied 2015; 4: 253-8.
11. Lai MKL, Cheung PWH, Cheung JPY. A systematic review of developmental lumbar spinal stenosis. Eur Spine J 2020; 29: 2187.
12. Arnoldi CC, Brodsky AE, Cauchoix J, et al. Lumbar spinal stenosis and nerve root entrapment syndromes: definition and classification. Clin Orthop Relat Res 1976; 115: 4-5.
13. Karantanas AH, Zibis AH, Papaliaga M, et al. Dimensions of the lumbar spinal canal: variations and correlations with somatometric parameters using CT. Eur Radiol 1998; 8: 1581–5.
14. Hennemann S, Abreu MR. Degenerative Lumbar Spinal Stenosis. Rev Bras Ortop 2021; 56: 9–17.
15. Verbiest H. The significance and principles of computerized axial tomography in idiopathic developmental stenosis of the bony lumbar vertebral canal. Spine 1979; 4: 369–78.
16. Lim YS, Mun JU, Seo MS, et al. Dural sac area is a more sensitive parameter for evaluating lumbar spinal stenosis than spinal canal area: A retrospective study. Medicine (Baltimore) 2017; 9087.
17. Simel DL, Rennie D. Low back pain, lumbar spinal stenosis. The rational clinical examination: evidence-based clinical diagnosis. McGraw-Hill Education New York 2016.
18. Macedo LG, Bodnar A, Battie MC. A comparison of two methods to evaluate a narrow spinal canal: routine magnetic resonance imaging versus three-dimensional reconstruction. Spine J 2016; 16: 884–8.
19. Roudsari B, Jarvik JG. Lumbar spine MRI for low back pain: Indications and yield. AJR Am J Roentgenol 2010; 195: 550‑9.
20. Malfair D, Beall DP. Imaging the degenerative diseases of the lumbar spine. Magn Reson Imaging Clin N Am 2007; 15: 221-38.
21. Hansson T, Suzuki N, Hebelka H, et al. The narrowing of the lumbar spinal canal during MRI: the effects of the disc and ligamentum flavum. Eur Spine J 2009; 18: 679–86.
22. Kanno H, Ozawa H, Koizumi N, et al. Increased facet fluid predicts dynamic changes in the dural sac size on axial-loaded MRI in patients with lumbar spinal canal stenosis. American Journal of Neuroradiology 2016, 37: 730-5.
23. Sions JM, Rodriguez CA, Pohlig RT, et al. Epidural fat and its association with pain, physical function, and disability among older adults with low back pain and controls. Pain Med 2018; 19: 1944–51. 
24. Beajeux R, Wolfram-Gabel R, Kehrli P, et al. Posterior lumbar epidural fat as a functional structure? Histologic specificities. Spine 1997; 22: 1264–8.
25. Reina M, Franco C, Lopez A, et al. Clinical implications of epidural fat in the spinal canal. A scanning electron microscopic study. Acta Anaesthesiol Belg 2009; 60: 7–17.
26. Fassett DR, Schmidt MH. Spinal epidural lipomatosis: a review of its causes and recommendations for treatment. Neurosurg Focus 2004; 16: 11.
27. Jensen RK, Jensen TS, Koes B, et al. Prevalence of lumbar spinal stenosis in general and clinical populations: A systematic review and meta-analysis. Eur Spine J 2020; 29: 2143-63.
28. Kim YU, Kong YG, Lee J, et al. Clinical symptoms of lumbar spinal stenosis associated with morphological parameters on magnetic resonance images. Eur Spine J 2015; 24: 2236–43.
29. Marawar SV, Ordway NR, Madom IA, et al. Comparison of surgeon rating of severity of stenosis using magnetic resonance imaging, dural cross-sectional area, and functional outcome scores. World Neurosurg 2016; 96: 165–70.
30. Verbiest H. Neurogenic intermittent claudication in cases with absolute and relative stenosis of the lumbar vertebral canal (ASLC and RSLC), in cases with narrow lumbar intervertebral foramina, and in cases with both entities. Clin Neurosurg 1973; 20: 204-14.
31. Wiesel SW, Tsourmas N, Feffer HL, et al. A study of computer-assisted tomography. I. The incidence of positive CAT scans in an asymptomatic group of patients. Spine 1984; 9: 549–51.
32. Haig AJ, Geisser ME, Tong HC, et al. Electromyographic and magnetic resonance imaging to predict lumbar stenosis, low-back pain, and no back symptoms. J Bone Joint Surg Am 2007; 89: 358-66.
33. Boden SD, Davis DO, Dina TS, et al. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am 1990; 72: 403-8.
34. Korse NS, Kruit MC, Peul WC, et al. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients. PLoS One 2017; 12: e0186148.
35. Pierro A, Cilla S, Maselli G, et al. Sagittal normal limits of lumbosacral spine in a large adult population: a quantitative magnetic resonance imaging analysis. J Clin Imaging 2017; 7: 35.
36. Altinel F, Yerli H. Clinical and Radiological Analysis of Dural Sac Diameter in Lumbar Spinal Stenosis. EJMI 2020; 4: 149–54.
37. Hurri H, Slatis P, Soini J, et al. Lumbar spinal stenosis: assessment of longterm outcome 12 years after operative and conservative treatment. J Spinal Disord 1998; 11: 110–5.
38. Nikhil J, Shankar A, Nitin MA, et al. Lumbar canal stenosis: a prospective clinicoradiologic analysis. J Neurol Surg A Cent Eur Neurosurg 2020; 81: 387-91.
39. Premchandran D, Saralaya VV, Mahale A. Predicting lumbar central canal stenosis—a magnetic resonance imaging study. J Clin Diagn Res 2014; 8: 01-4.
40. Rapala K, Chaberek S, Truszcynska A, et al. Digital computed tomography affords new measurement possibilities in lumbar stenosis. Ortop Traumatol Rehabilitation 2009; 11; 13-26.
41. Maus TP. Radiologic assessment of the patient with spine pain. Raj’s practical management of pain. Elsevier Inc 2008; 12: 217–77.
42. Malmivaara A, Slates P, Heliovaara M. Surgical or nonoperative treatment for lumbar spinal stenosis? A randomized controlled trial. Spine 2007; 32: 1–8.
43. Schönström NS, Bolender NF, Spengler DM. The pathomorphology of spinal stenosis as seen on CT scans of the lumbar spine. Spine 1985; 10: 806–11.
44. Ulrich CG, Binet EF, Sanecki MG, et al. Quantitative assessment of the lumbar spinal canal by Computed Tomography. Radiology 1980; 134: 137-43.
45. Hamanishi C, Matukara N, Fujita M. Cross sectionalare of the stenotic lumbar dural tube measured from transverse views of MRI. J Spinal Discord 1994; 7: 388- 93.
46. Danielson BI, Willén J, Gaulitz A, et al. Axial loading of the spine during CT and MR in patients with suspected lumbar spinal stenosis. Acta Radiol 1998; 39: 604-11.
47. Schönström N, Hansson T. Pressure changes following constriction of the cauda equina. An experimental study in situ. Spine (Phila Pa 1976) 1988; 13: 385-8.
48. An SJ, Mun JU, Kang KN, et al. Superior articular process cross-sectional area is a new sensitive parameter for the diagnosis of lumbar central canal spinal stenosis. Clin Interv Aging 2018; 13: 1763-7.
49. Barry M, Livesley P. Facet joint hypertrophy: the cross-sectional area of the superior articular process of L4 and L5. Eur Spine J 1997; 6: 121-4.
50. Genevay S, Atlas SJ. Lumbar spinal stenosis. Best Pract Res Clin Rheumatol 2010; 24: 253-65.
51. Fujita M, Kawano H, Kitagawa T, et al. Preoperative design for the posterolateral approach in full-endoscopic spine surgery for the treatment of l5/s1 lumbar disc herniation. Neurospine 2019; 16: 105-12.
52. Kim K, Mendelis J, Cho W. Spinal epidural lipomatosis: a review of pathogenesis, characteristics, clinical presentation, and management. Glob Spine J 2019; 9: 658-65.
53. Kumar K, Nath RK, Nair CP, et al. Symptomatic epidural lipomatosis secondary to obesity: case report. J Neurosurg 1996; 85: 348–50.
54. Quint DJ, Boulos RS, Sanders WP, et al. Epidural lipomatosis. Radiology 1988; 169: 485-90.
55. Fogel GR, Cunningham PY III, Esses SI. Spinal epidural lipomatosis: case reports, literature review and meta-analysis. Spine J 2005; 5: 202-11.