Ileal Diverticulitis.

Teaching Point: Terminal ileal diverticulitis is an uncommon cause of right lower abdominal pain.

The Claustrum Sign in Febrile Infection-Related Epilepsy Syndrome (FIRES).

Teaching Point: Bilateral mesiotemporal edema and the claustrum sign can be seen in febrile infection-related epilepsy syndrome (FIRES) and new onset refractory status epilepticus (NORSE) but are neither diagnostic nor pathognomonic for these entities.

Clash of the titans: Current CT and CT-like imaging modalities in sacroiliitis in spondyloarthritis.

Sacroiliitis is characterised by active and structural changes of the joint. While the Assessment of Spondyloarthritis international Society (ASAS) classification criteria stress the importance of bone marrow inflammation, recent reports suggest that osteitis can occur in various diseases, mechanical conditions and healthy individuals. Thus, structural lesions such as joint surface erosion and ankylosis are important factors for differential diagnosis. Various imaging modalities are available to examine these changes. However, computed tomography (CT) is generally considered the reference standard. Nonetheless, recent advances in magnetic resonance imaging (MRI) allow for direct bone imaging and the reconstruction of CT-like images that can provide similar information. This way, the ability of MRI to detect and measure structural lesions is strengthened. The aim of this review is to provide an overview of the pros and cons of CT and CT-like imaging modalities in sacroiliitis.

Baló Concentric Sclerosis.

Teaching Point: Baló concentric sclerosis is a rare subtype of multiple sclerosis, characterized by a concentric layered mass on magnetic resonance imaging.

Pneumococcal Meningitis.

Teaching Point: Spontaneous, atraumatic pneumocephalus is a rare presentation of pneumococcal meningitis.

Nasal and Nasopharyngeal Rosai-Dorfman Disease.

Teaching Point: Nasal and nasopharyngeal Rosai-Dorfman disease is a rare cause of nasal obstruction.

Behçet Disease.

Teaching Point: Although Behçet disease is a multisystemic and chronic vasculitis, it can be superimposed with a variety of acute vasculitis.

Cecal Volvulus.

Teaching Point: The coffee bean sign, the whirl sign, and the bird's beak sign are the key findings on abdominal CT of cecal volvulus.

Deep Pelvic Endometriosis.

Teaching Point: Magnetic resonance imaging allows adequate evaluation of the location, size and subperitoneal lesion extension of deep pelvic endometriosis, providing key information for both the diagnosis and treatment planning.