Vertebral pneumatocysts refers to the presence of a gas-filled cavity within the vertebrae, more prevalent on the cervical spine. Intraosseous pneumatocysts are more common adjacent to the sacroiliac joint while it is rare in the vertebral column. Other causes of vertebral gas e.g. Kümmell disease, osteomyelitis, post-surgery and necrotic tumour should be excluded.
Although not completely understood, some authors believe it is an extension from the intradiscal gas (vacuum phenomenon) 1. On follow up, these lesions changed to fluid-filled cavities and became granulation tissue later on 2. Some of these lesions enlarged in size 1.
Difficult to detect but sometimes gas lucencies are seen within the vertebral bodies.
Considered the best method of diagnosis. Gas measures about -800 to -1000 HU in density. Detection of associated intradiscal gas and communication between the vertebral and intradiscal gas can be demonstrated. Also epidural extension can be easily detected.
Gas appears as low signal on both T1 and T2 which can be confused with sclerotic lesions so CT is definitive.
Treatment and prognosis
Follow up to detect any increase in the size but no specific treatment.
Sclerotic lesions e.g. metastasis, Kümmell disease, vertebral osteomyelitis, post-surgery and tumour with necrosis.
- 1. Kitagawa T, Fujiwara A, Tamai K et-al. Enlarging vertebral body pneumatocysts in the cervical spine. AJNR Am J Neuroradiol. 2004;24 (8): 1707-10. Pubmed citation
- 2. Yamamoto T, Yoshiya S, Kurosaka M et-al. Natural course of an intraosseous pneumatocyst of the cervical spine. AJR Am J Roentgenol. 2002;179 (3): 667-9. doi:10.2214/ajr.179.3.1790667 - Pubmed citation