Emphysematous Pyelitis

Differentiate this entity from emphysematous pyelonephritis, where gas is seen within the renal parenchyma, not just the collecting system.

Emphysematous pyelitis is a less severe diagnosis, requiring only antibiotics in most cases.

Osteochondroma

Palpable lump.

Osteosarcoma

Note the aggressive periosteal reaction:
Codman's triangle
Hair on end
Sunburst

Medulloblastoma

9 y.o

Interhemispheric lipoma vs. Fatty falx

Note:
- Interhemispheric lipoma is associated with agenesis of the corpus callosum.
- Differentiate this appearance from a ruptured dermoid cyst (fat droplets in the SA space).

Prostatitis

UA: leukocytes, RBCs, +ve nitrates,

Ascites - Delineation of intraperitoneal cavity

Breast cancer, liver mets.