Vertebral pneumatocysts refer to the presence of air 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 air e.g. Kummel disease, osteomyelitis, post surgery and necrotic tumor should be excluded.
Although not completely understood, some authors believe it is an extension from the intradiscal air (vacuum phenomenon) 1. On follow up of these lesions they 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 air lucencies are seen within the vertebral bodies.
Considered the best method of diagnosis. Air measures about -800 to -1000 HU in density. Detection of associated intradiscal air and communication between the vertebral and intradiscal gas can be demonstrated. Also epidural extension can be easily detected.
Air appears as low signal on both T1 and T2 which confuses with sclerotic lesions so CT is pathognomonic.
Treatment and prognosis
Follow up to detect any increase in the size but no specific treatment.
Sclerotic lesions e.g. metastasis, Kummel 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