Radiology Packet 16 Skull

16 wk old puppy HX = presented for routine vaccinations, owner reports puppy is very lethargic, very quiet, and sometimes appears disoriented

16 wk old puppy RF –The cranial vault is relatively large and the inner surface is smooth and homogenous, lacking the usual ridges of bone that indicate the brain sulci. –Discontinuity of the cranial bones is noted in the most dorsal aspect. RD –Hydrocephalus (congenital) –Open fontanelle

16 wk old kitten HX = presented for acute injury of falling from a porch step (10” high) and is now tetraparetic

16 wk old kitten RF –Marked mal-alignment of the spine at the level of C1-C2 visible in the lateral view. –Note the greatly increased space between the dorsal arch of C1 and the large spinous process of C2. –There is an impression of ventral angulation of the dens (odontoid process of C2). RD –Atlanto-axial subluxation Next –Surgical reduction and stabilization of the atlanto-axial subluxation

2 yr old female Pomeranian “Penny” HX = presented with ataxia and disorientation

2 yr old female Pomeranian “Penny” RF –Enlargement of the occipital foramen. –Increased size of the cranial vault and the inner surface of the calvarium is smoother than normal. RD –Occipital dysplasia –Possible hydrocephalus

5 yr old FS Mix Canine “Brandy” HX = hit by car, on physical exam the dog seems painful when head is manipulated

5 yr old FS Mix Canine “Brandy”

RF –In the DV view a comminuted fracture of the right hemimandible is visible, it is at the junction of the horizontal and vertical rami in the region of the coronoid process. RD –Comminuted fracture of the right hemimandible Next –Surgical stabilization of the fracture (plate or cerclage wire)

1 yr old female GSD “Penny” HX = Presented for difficulty in opening mouth, eosinophilia is present on the CBC. Also, prior history of being bitten in the region of the tempromandibular area when she was a puppy.

1 yr old female GSD “Penny”

RF –A large, well circumscribed mineralized mass is seen between the ramus of the mandible and the zygomatic arch on the left, it is mottled in appearance. –The origin is hard to define but it appears to be arising from the lateral margin of the mandible. –The zygomatic arch is thickened in the area of the mass. RD –R/O: Osteoma Osteochondroma Calcinosis circumscripta (tumoral calcinosis) Next –Biopsy