Abstract
The extradural space is currently investigated through fluoroscopy and ultrasound for surgical approach, whereas magnetic resonance imaging has been used to provide detailed information. The aim of the present paper is to describe the radiologic anatomy of the sacral canal through a review of its appearance in the different radiologic techniques. CT is able to visualise also the sacrum and the content of the sacral canal, triangular in shape in the transverse images, being able to establish the measurement of the transverse area of the dural sac and of the canal diameter. On the sagittal CT scans, the sacrococcygeal membrane appears as a hypodense structure, between the posterior end of the sacral vertebra and the posterior tip of the coccyx. In magnetic resonance imaging, on T2-sagittal plane images, the sacral canal appears hyperintense, due to the presence of the liquor. The dural sac appears as a hypointense band and its termination as hypointense cul de sac in the context of the hyperintensity of the sacral canal. The sacrococcygeal membrane appears as a hypointense band between the posterior end of the sacral vertebra and the posterior tip of the coccyx. On ultrasound imaging, in the transverse sonographic view, two hyperechoic reversed U-shaped structures correspond to the two bony prominences of sacral cornua, between which there were two hyperechoic band-like structures. The band-like structure on top is the sacrococcygeal ligament. The band-like structure at the bottom is the dorsal surface of the sacrum. The sacral hiatus corresponds to the hypoechoic region observed between the two hyperechoic band-like structures.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Brailsford JF (1953) The radiology of bones and joints. J & A Churchill, London
Romanes GJ (ed) (1981) Cunningham’s textbook of anatomy, 12th edn. Oxford University Press, Oxford, UK
Standring S, Borley NR, Collins P, Crossman AR, Gatzoulis MA, Healy JC, Johnson D, Mahadevan V, Newell RLM, Wigley CB (eds) (2008) Gray’s anatomy, ed 40. Churchill Livingstone, Spain, pp 1002–1003
Boone D, Parsons D, Lachmann SM, Sherwood T (1985) Spina bifida occulta: lesion or anomaly? Clin Radiol 36:159–161
Avrahami E, Frishman E, Fridman Z, Azor M (1994) Spina bifida occulta of S1 is not an innocent finding. Spine 19:12–15
Albrecht TL, Scutter SD, Henneberg M (2007) Radiographic method to assess the prevalence of sacral spina bifida occulta. Clin Anat 20:170–174
Botwin KP, Thomas S, Gruber RD, Torres FM, Bouchlas CC, Rittenberg JJ, Rao S (2002) Radiation exposure of the spinal interventionalist performing fluoroscopically guided lumbar transforaminal epidural steroid injections. Arch Phys Med Rehabil 83:697–701
Chen CP, Tang SF, Hsu TC, Tsai WC, Liu HP, Chen MJ, Date E, Lew HL (2004) Ultrasound guidance in caudal epidural needle placement. Anesthesiology 101:181–184
Grau T, Leipold RW, Horter J, Conradi R, Martin E, Motsch J (2001) The lumbar epidural space in pregnancy: visualization by ultrasonography. Br J Anaesth 86:798–804
Grau T, Leipold RW, Horter J, Conradi R, Martin EO, Motsch J (2001) Paramedian access to the epidural space: the optimum window for ultrasound imaging. J Clin Anesth 13:213–217
Park JH, Koo BN, Kim JY, Cho JE, Kim WO, Kil HK (2006) Determination of the optimal angle for needle insertion during caudal block in children using ultrasound imaging. Anaesthesia 61:946–949
Willschke H, Bosenberg A, Marhofer P, Willschke J, Schwindt J, Weintraud M, Kapral S, Kettner S (2007) Epidural catheter placement in neonates: sonoanatomy and feasibility of ultrasonographic guidance in term and preterm neonates. Reg Anesth Pain Medic 32:34–40
Willschke H, Marhofer P, Bosenberg A, Johnston S, Wanzel O, Sitzwohl C, Kettner S, Kapral S (2006) Epidural catheter placement in children: comparing a novel approach using ultrasound guidance and a standard loss-of-resistance technique. Br J Anaesth 97:200–207
Yoon JS, Sim YH, Kim SJ, Kim WS, Koh SB, Kim BJ (2005) The feasibility of color Doppler ultrasonography for caudal epidural steroid injection. Pain 118:210–214
Macdonald A, Chatrath P, Spector T, Ellis H (1999) Level of termination of the spinal cord and the dural sac: a magnetic resonance study. Clin Anat 12:149–152
Zacchi C, Macchi C, Fiore D (2000) Radiologic anatomy, vol 15. CEDAM, Padova, p 35
Ballinger PW, Frank ED (1999) Merrill’s atlas of radiographic positons and radiologic procedures, 9th edn. Mosby, St. Louis, MO
Moller TB, Reif E (1997) Pocket atlas of radiographic positioning. Thieme, New York, pp 74–77
Bontrager KL, Lampignano JP (2001) Textbook of radiographic positioning and related anatomy, 6th edn. Mosby, St. Louis, MO
Lippert JA, McGraw JK (2002) Spine interventions. Sem Roentgenol 37:266–281
Jones SB, Shaw DW, Jacobson LE (1997) A transsacral approach through the sacral hiatus for myelography. AJR Am J Roentgenol 169:1179–1181
Zheng F, Farmer JC, Sandhu S, O’Leary PF (2006) A novel method for the quantitative evaluation of lumbar spinal stenosis. HSSJ 2:136–140
Solomon LB, Rühli FJ, Lee YC, Henneberg M (2009) Secular trend in the opening of the sacral canal: an Australian study. Spine 34:244–248
Grossterlinden L, Begemann PG, Lehmann W, Nuechtern J, Schumacher U, Nagel HD, Linhart W, Adam G, Rueger JM, Briem D (2009) Sacroplasty in a cadaveric trial: comparison of CT and fluoroscopic guidance with and without balloon assistance. Eur Spine J 18(8):1226–1233
Scapinelli R (1990) Anatomical and radiologic studies on the lumbosacral meningo-vertebral ligaments of humans. J Spinal Disord 3:6–15
Adewale L, Dearlove O, Wilson B, Hindle K, Robinson DN (2000) The caudal canal in children: a study using magnetic resonance imaging. Paediatr Anaesth 10:137–141
Crighton IM, Barry BP, Hobbs GJ (1997) A study of the anatomy of the caudal space using magnetic resonance imaging. Br J Anaesth 78:391–395
Edward R (2005) Ultrasound-guided caudal epidural injection. Anesthesiology 102:693
Huang J (2005) Disadvantages of ultrasound-guided caudal epidural needle placement. Anesthesiology 102:693
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2011 Springer-Verlag/Wien
About this chapter
Cite this chapter
Macchi, V., Porzionato, A., Morra, A., Stecco, C., De Caro, R. (2011). Radiologic Anatomy of the Sacral Canal. In: Alexandre, A., Masini, M., Menchetti, P. (eds) Advances in Minimally Invasive Surgery and Therapy for Spine and Nerves. Acta Neurochirurgica Supplementum, vol 108. Springer, Vienna. https://doi.org/10.1007/978-3-211-99370-5_2
Download citation
DOI: https://doi.org/10.1007/978-3-211-99370-5_2
Published:
Publisher Name: Springer, Vienna
Print ISBN: 978-3-211-99369-9
Online ISBN: 978-3-211-99370-5
eBook Packages: MedicineMedicine (R0)