1. Interactive Case Tutorial

2.  Review the history and signalment for the client  Evaluate the radiographs provided  Explore the interactive images and compare the answers given with your own interpretations. When you’ve clicked on the image, click the same spot again to make the label disappear.  Answer the questions regarding a diagnosis and recommendations  Review the radiologist’s findings

3.  Signalment: 4 year old, MI, Standard poodle  History: on and off lameness for 3 weeks which started after playing roughly with another dog; still lame after rough play despite rest  Study: Extended limb VD and lateral views of the pelvis through stifles; lateral views of the stifles

4. Normal Right Hip Dystrophic mineral (previous trauma?) Right thigh atrophy Solid periosteal reaction Moth-eaten and permeative lysis distal diaphysis and metaphysis Normal tibial tubreosity (stifle is rotated) Normal Left Hip Digital artifact

5. Transitional vertebra Normal pelvis Moth-eaten and permeative lysis distal diaphysis and metaphysis

6. LEFTRIGHT Normal left stifleNo swellingCortical lysis Moth-eaten and permeative lysis distal diaphysis and metaphysis Enlarged popliteal lymph node Mild intracapsular stifle swelling

7.  Provide a diagnosis based on your findings. Submit There is an aggressive lesion of the distal right femur with popliteal lymphadenopathy. Differentials include neoplasia (for example, primary bone tumor or histiocytic sarcoma) with lymph node metastasis and fungal osteomyelitis. Atrophy of the right pelvic limb is from disuse. Feedback Continue

8.  Provide your recommendation for this client. Submit Aspiration of the popliteal lymph node for cytology, fine-needle or core biopsy of the distal right femoral lesion, thoracic radiographs to assess for fungal pneumonia or metastatic disease Feedback Continue

9.  Right femur:  The distal diaphysis and metaphysis has moth- eaten and permeative lysis  Cortical lysis is present at the medial trochlear ridge  Irregularly shaped but smoothly margined uniform periosteal reaction is at the medial and caudal cortex of the distal femoral diaphysis  The right popliteal lymph node is enlarged  The right stifle has mild intracapsular swelling  The right pelvic limb has muscle atrophy

10.  The owner declined any further work-up and chose comfort care for her pet