Fig. 5.

Systemic involvement. a A 26-year-old female with neurotuberculosis. Sagittal post-contrast T1-weighted MRI with fat saturation shows collapse of thoracic vertebrae, destruction of the interposed vertebral disc, prevertebral and intervertebral fluid collection with peripheral enhancing margins and diffusely enhancing remainder of the thoracic vertebrae, suggesting spondylodiscitis with abscess formation, known as Pott’s disease. Due to displacement and mass effect narrowing of the spinal canal with compression of the spinal cord. b Axial high-resolution CT scan (right lung) in the same patient showing ‘miliary tuberculosis’ with innumerable small pulmonary nodules with centrilobular distribution. c A 37-year-old female with a typical erythema migrans, as a disease-specific finding in Lyme disease. d A 20-year-old female affected by Susac’s syndrome with branch retinal artery occlusion. Fundus photography of the left eye shows ischaemic retinal oedema and narrowed branches of the superior and inferior temporal arteries. e A 24-year-old female affected by Erdheim–Chester disease with a sclerotic metaphyseal lesion in the tibia as a disease-specific finding