Imaging in Pott's spine: A review of typical and atypical imaging features and diagnostic challenges

Pott's spine is associated with high morbidity, long-term disabling sequelae and even mortality. The classical paradiscal form, where there is destruction of end plates of adjacent 2-3 vertebral bodies along with intervening disc involvement and associated paravertebral abscess is well recognized. However, due to its varied clinical and radiological presentations, it remains a diagnostic challenge often resulting in delay in diagnosis. This is especially true of countries where tuberculosis has been almost eliminated but now are witnessing increase in incidence both due to immigration and HIV infection. Overlooking tuberculosis as a differential diagnostic consideration is very likely when the radiological presentation is not classical and consequent delay in diagnosis may have devastating consequences for the patient. In this review, we aim to describe various typical and atypical imaging findings of Pott's spine with special emphasis on atypical presentations including single vertebral body involvement, isolated posterior element involvement, intraspinal epidural abscess without vertebral involvement and skip lesions along with differential diagnostic considerations like metastases, fractures and spinal infections. The major focus is on magnetic resonance imaging findings which is the imaging modality of choice in patients presenting with neurological symptoms referable to the spine. Radiographic and Computed tomography findings are also discussed in brief. We also describe treatment and post treatment imaging in brief. Radiologists need to be aware of these atypical presentations as they may be the first to raise the possibility of tuberculosis which can avoid disabling long term sequalae.