Inverted Napoleon Hat Sign

Radiograph of LS Spine shows abnormal contour of the L5 vertebra.

Close-up view of the same.

Inverted magnified image of L5 showing the hat like contour of L5 vertebra.

Picture of Napoleon wearing his hat in the inset. Right side image is inverted to show the hat like appearance of L5 vertebra more clearly.

The reason for this is due to spondylolysis of L5 (defects in pars interarticularis) and signficant anterolisthesis (here grade II) over S1 vertebra, which is showing in this lateral radiograph.

Supracondylar humeral fracture

Blue arrows point to the elevated / displaced anterior and posterior fat pads. Orange arrows point to the fracture.

Venous Intravasation during HSG

Venous intravasation when using water soluble contrast media, is considered an innocuous finding. May be seen up to 6% of cases, sometimes even in healthy patients. Common causes include recent uterine surgery, tubal block and excessive injection pressures.

REFERENCE:
Ubeda B, Paraira M, Alert E, Abuin RA. Hysterosalpingography: spectrum of normal variants and nonpathologic findings. AJR Am J Roentgenol. 2001 Jul;177(1):131-5.

Parieto-occipital encephalomalacia in a child

 12yr old with repeated seizures.

Bilateral parietal and occipital gliotic-encephalomalacic changes are noted, almost in a symmetrical manner.

Cavernous Sinus Dermoid Cyst

Clinical History : 60yr old female patient with right 3rd nerve palsy. Suspecting a PCom aneurysm, CT angiogram was performed which showed no intracranial aneurysms.

However a heterogenously hypodense non-enhancing lesion was seen in the right cavernous sinus, with cavernous ICA seen medially displaced. Lesion anteriorly showed markedly hypodense area of negative attenuation varying from -100 to -150HU, suggesting intralesional fat. Posterior rim of the lesion showed small calcfications. Lateral hyperdense rim was thought to represent the thickened dural layer of cavernous sinus.