Imaging of musculoskeletal tuberculosis.

Tuberculosis (TB) represents a major public health problem worldwide. Any tissue may be infected. Involvement of the musculoskeletal (MSK) system account for 1-3% of all tuberculous infections. MSK TB may manifest as tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue infections. Although TB spondylitis may present with distinctive imaging features compared to pyogenic infections of the spine, the imaging semiology of extra-spinal TB infections is mostly nonspecific and may mimic other lesions. TB infections should therefore always be considered in the differential diagnosis, particularly in immunocompromised patients. The aim of this article is to review the imaging features of spinal and extra-spinal MSK TB. Magnetic resonance imaging is considered the modality of choice to make the diagnosis and to evaluate the extent of the disease.

"Swirl sign" of aggressive angiomyxoma-a lesser known diagnostic sign.

Aggressive angiomyxoma is a rare mesenchymal tumor with high rate of local recurrence, found mainly in the pelvis and perineum of women of reproductive-aged group. We present cases of two patients, with emphasis on the magnetic resonance (MR) imaging characteristics. The clinical presentation was nonspecific. MR imaging revealed characteristic "swirl sign" in T2-weighted sequence. Preoperative diagnosis could not be made in the first patient due to a lack of experience about the diagnosis. Preoperative diagnosis was made in the second case and was helpful for the surgeon to excise the mass completely. Aggressive angiomyxoma should be on the top of a differential diagnosis in the appropriate clinical and imaging scenario.