Avascular necrosis of spine: a rare appearance

Avascular necrosis (AVN) of two contiguous vertebrae along with the intervening disc is presented. AVN of two contiguous vertebrae and the intervening disc is a rare entity and can be confused with infective and neoplastic processes. We present the role of magnetic resonance imaging (MRI) in the diagnosis of AVN. AVN of vertebral bodies is a known entity; however, involvement of two contiguous vertebrae along with the intervening disc is atypical. The imaging features can be confused with an infective etiology, which involves the disc more commonly as compared to AVN. Neoplastic destruction of vertebrae also needs to be ruled out in appropriate clinical situations. Frontal and lateral radiographs of the lumbar spine were performed followed by an MRI. Subsequently CT-guided fine needle aspiration cytology was performed. These radiographic features were correlated with the clinical and pathologic findings. The MRI findings of a wedge-shaped lesion with classic fluid intensity (hyperintense signal, like that of cerebrospinal fluid on T2-weighted images) are characteristic of AVN. Fine needle aspiration cytology confirmed the diagnosis and excluded an infective or a neoplastic process. The MRI findings described in this report are very characteristic of AVN of spine. Clinical and radiologic correlation could help in making the diagnosis and avoid unnecessary investigations.