A case of a 75-year old male with right-sided exopthalmos is presented. Outside proptosis of the right eye was initially observed 6 years ago. Opthalmological and endocrinological clinical examination as well as laboratory tests revealed no pathology from optic nerve disc, optic bulb and thyroid related hormones. MRI study demonstrated an optic nerve meningioma. The key imaging findings and the differential diagnosis were discussed in this present paper. Case presentationA 75-year old male presents to our department with rightsided exopthalmos. Outside proptosis of the right orbital bulb in comparison with the left was initially observed 6 years ago. The patient visited an ophthalmologist and endocrinologist. Fundoscopic examination revealed no atrophy or oedema of the optic disc and no lesion of the optic bulb. Thyroid related hormones were measured within normal limits. The patient did not proceed to any imaging examinations and returned home. He was under steroid treatment with no response and comes to the hospital nowadays still presenting the same painless symptom (exopthalmos with no prominent change), however claiming visual colour disturbance. Fundoscopy and thyroid hormones still revealed no abnormal findings. MRI study of the orbital cavities was performed. In the MRI protocol T2, T2 with fat saturation, T1, T1 with fat saturation sequences, pre-and post gadolinium injection on axial, sagital and coronal planes were performed. A tubular mass was demonstated in the right orbit showing widening along the length of the nerve sheath and an anterior nerve expansion towards the globe. The mass appeared as isointense to brain and optic nerve tissue on T1 weighted images ( Fig. 1) and slightly hyperintense on T2 weighted images (Fig. 2). On T1 weighted images with fat saturation after intravenous administration of paramagnetic substance (gadolinium) the mass presented a homogeneous intense enhancement suggesting in appearance a "tram track" around the hypointense optic nerve (Fig. 3). There is no intracranial extension of the lesion (Fig. 1) or any evidence of surrounding structures invasion (Fig. 3). The presence of optic nerve sheath meningioma was assumed.

The case of a 6-month old male infant presenting at the emergency department with fever and swelling at the left knee joint is discussed. Laboratory tests showed an inflammatory condition. Left knee plain radiograph demonstrated local soft tissue oedema. Percutaneous needle aspiration of articular fluid showed a positive culture for Staphylococcus aureus. The diagnosis of septic arthritis was confirmed. Because of inadequate response to treatment an MRI study was followed to evaluate possible abscesses. The presence of an abscess in the suprapatellar bursa was confirmed and an additional inflammatory process of the bone marrow was revealed, consistent with osteomyelitis. The pathophysiology, the imaging findings, the patient’s management and a review of septic arthritis and osteomyelitis coexistence are presented in this paper.