Occular Metallic Foreign body

17 year old male CT coronal, axial and coronal bone window showing metallinc foreign body in the right globe adherent to lateral wall.
Metallic foreign body in another patient in right orbit on radiograph (arrow). CT scan axial section of the same patient showing foreign body just posterior to the limbus which is extra occular.

Intraocular foreign bodies (IOFBs) are rather variable in presentation, outcome, and prognosis. With increased awareness and advanced surgical techniques, the outcome and the prognosis for these potentially devastating injuries have substantially improved.

CT scans are the imaging study of choice for IOFB localization. A helical CT scan is the most efficient method to establish a diagnosis. Helical CT scans have a very high identification rate. With conventional CT scans, cuts of 0.5 mm are advised. With the advent of MDCT the role of radiologist has become easier in identification and diagnosis of occular foreign body. Plain x-ray is useful if a metallic IOFB is present and a CT scan is unavailable. MRI is generally not recommended for metallic IOFBs. Ultrasound is a useful tool in localizing IOFBs, and its careful use is possible even if the globe is still open; alternatively, intraoperative use after wound closure can be attempted. The ultrasound biomicroscope may help with IOFBs in the anterior segment.

Tarlov Cyst

25 year old young male came with radicular pain to lower limb on right side referred for MRI LS spine. MRI T2 weighted para saggital image shows well defined rounded hyperintense lesion in the D12-L1 intervertebral foramen causing compression on the exiting nerve root on right side. CISS 3D axial image shows the lesion better (arrow).

Tarlov or perineurial cysts are pathological formations located in the space between the peri-and endoneurium of the spinal posterior nerve root sheath. Tarlov cysts are rare causes of low back pain. They are more common in females. Clinical presentation of Tarlov cysts is variable. The cysts may cause local and/or radicular pain. Depending on their location, size and relationship to the nerve roots, they may cause sensory disturbances or motor deficits to the point of bladder dysfunction.

Radiograph is usually normal, it may show bony erosion or widening of foramen on oblique views. Conventional myelography may show extradural indentation on the thecal sac however MRI is needed for confirmation of the lesion. CT scan can demonstrate cystic lesion isodense with CSF located at the foramina. Bony changes may also be present. MRI shows welldefined CSF intensity lesion in the prineural location predominantly in lumbar and sacral region. The lesions may be seen in the cauda equina and other nerve roots.

Rheumatoid pneumoconiosis (Caplan's Syndrome)

High resolution CT of 84 year old man with rheumatoid arthritis. a) Mediastinal window image showing cavitatory lesions in bilateral upper lobes (arrows) with large fibrotic area in right upper lobe (arrow head) and few subpleural fibrotic lesions (arrows in image [b]) in left upper lobe. c) High resolution CT scan lung window shows multiple diffuse reticulonodular lesions in bilateral lungs these features suggestive of pneumoconiosis with progressive massive fibrosis (PMF).

It is also known as Caplan's Syndrome, associated with coal worker's pneumoconiosis and silicosis. The incidence is falling as the coal mining industry has been in decline. Chest radiograph shows multiple, well defined, rounded opacities, 0.5 to 5 cm in diameter distributed throughout the lungs with or without eggshell calcification of hilar lymph nodes. HRCT findings include small nodules with perilymphatic distribution associated with necrobiotic nodules demonstrating cavitation, which are indistinguishable from tubercular cavity. The active inflammatory zone around the rheumatoid pneumoconiotic nodules distinguishes from nonrheumatoid pneumoconiotic nodules. Progressive massive fibrosis (PMF) is irregularly outlined few soft tissue nodules with surrounding fibrosis in apical regions, more often seen with simple pneumoconiosis than Caplan’s syndrome.