Well the new quarter is in session so we are back at Known Case Conference to challenge the residents with reading radiographs.The case moderator knows the answer but the residents have to narrow it down to their best list of differential diagnoses.
We hold KCC rounds after work in a barn on the west side of town. Not just any barn, it’s fully equipped with light boxes, a projector and screen (for digital cases) and wireless internet. And beverages and snacks of course. This week I rode my bike out to the barn on a windy day. A large unidentified insect blew into my forehead and stung me, so I spent most of the session lamenting how much my head hurt! Anyway here are a few of the case summaries for you.
Case 1 – 8 year old male neutered dog with an acute abdomen
The abdominal radiographs had poor detail, and the contour of the abdominal wall was distended. The spleen was enlarged and curved in a “reverse C” shape on the lateral projection. The proximal extremity of the spleen was visible on the lateral ventral to the cecum, then the body curved caudally and the distal extremity was just caudal to the liver. The small intestine was displaced by this enlarged spleen. Differential diagnoses included splenic torsion, and inflammatory or diffuse infiltrative disease. Diagnosis: Splenic torsion. These have a very characteristic position and shape if there isn’t too much effusion obscuring them. There is no contour change such as with a mass. Check the v/d projection to see that the proximal extremity of the spleen is not visible in its normal position.
Case 2 – 1 year old male neutered German Shorthair Pointer with lethargy.
These thoracic radiographs had an asymmetric interstitial pattern that was most pronounced in the left cranial lung lobe. There was interstitial pattern dorsally as well, and the distribution was patchy. The heart and vessels were normal, as was the pleural space. Differentials included hemorrhage, atypical pneumonia or inflammatory disease, or non-cardiogenic edema. Diagnosis: hemorrhage from rodenticide toxicity. Hemorrhage is often asymmetrically distributed. Dogs with rodenticide toxicity may also have a widened medastinum from accumulation of blood.
Case 3 – 2 year old Australian Shepherd cross with left hind limb lameness.
A lateral radiograph of the spine and pelvis showed an aggressive bone lesion of L5 with permeative osteolysis and marked ventral new bone production. There was also faint periosteal reaction on one of the femurs. On the v/d, the left femoral neck was lytic with an apple core appearance. The left ileal wing was sclerotic with increased periosteal new bone. Differentials for aggressive polyostotic bone lesions: fungal osteomyelitis, bacterial osteomyelitis, neoplasia. The latter two are much less likely than fungal disease. Diagnosis: Coccidiodomycosis. Here’s a different case with coccidiodomycosis of the pelvis.
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