European Journal of Radiology Extra 66 (2008) e55–e57 The intravertebral vacuum phenomenon Erhan Akpinar, Baris Turkbey * , Bagdat Medeyev, Munci Oran Hacettepe University School of Medicine, Department of Radiology, Ankara, Turkey Received 12 February 2008; accepted 21 February 2008 Abstract Vertebral vacuum sign is an uncommon finding, which can easily mimic the air within the disc and can be overlooked. We present a case of intravertebral vacuum phenomenon with exquisite multidetector computed tomography and magnetic resonance imaging find- ings. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Trauma; Spine; Intravertebral vacuum sign; CT; MRI 1. Introduction The vacuum phenomenon appears as a radiolucent area vis- ible in synovial joints, intervertebral disks, and vertebrae [1]. This phenomenon is explained by gas accumulation, mostly nitrogen, produced by the surrounding soft tissues [2]. The intravertebral vacuum phenomenon, also termed “intravertebral vacuum cleft,” is an uncommon finding. Although the cleft is, in fact, filled with gas, the term “vacuum phenomenon” has become universally accepted [3]. The aim of this paper is to present the multislice computed tomography and magnetic res- onance imaging findings of intravertebral vacuum sign in a patient with acute osteoporotic traumatic vertebral compression fracture. 2. Case report A 74-year-old female was admitted to the hospital with his- tory of trauma, abdominal pain and intestinal obstruction. Her past medical history was unremarkable except hypertension and osteoporosis. Physical examination revealed generalized * Corresponding author at: HUTF Radyoloji AD, Sihhiye 06100, Ankara, Turkey. Tel.: +90 3123051188; fax: +90 3123112145. E-mail address: bturkbey@yahoo.com (B. Turkbey). abdominal tenderness. She was hemodynamically stable with blood pressure of 160/95 mmHg, pulse 84 bpm, respiratory rate 18/min and oxygen saturation 95%. Patient’s laboratory workup was normal. Abdominal X-ray obtained in the supine position and abdominal ultrasound (US) examinations were normal. For further evaluation contrast-enhanced abdominal multislice CT examination was performed (3 mm slice thick- ness with 1.5 mm reconstruction increment). CT demonstrated a burst fracture of L1 vertebral body, paravertrebral hem- orrhage and air within the vertebral body consistent with intravertebral vacuum sign. Additionally the anteroposterior diameter of spinal canal at this level was found to be nar- rowed (Fig. 1). In order to clarify a possible spinal cord injury, magnetic resonance imaging (MRI) was done. MRI con- firmed the CT findings, but no spinal cord injury was depicted (Fig. 2). An intervention was not planned for the burst fracture; nonsteroidal anti-inflammatory (NSAID) drug therapy and elec- trolyte replacement were given. The symptoms of the patient resolved and she was discharged after 5 days of hospitaliza- tion. 3. Discussion The mechanism of gas accumulation within the vertebral body is poorly known [3]. The main hypothesis is the ischemic theory. Maldague reported the association between the pres- 1571-4675/$ – see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2008.02.006