Small Animal Pelvis Imaging RVT: Chapter 21

Objectives: Pelvis & Hind Limb Know general considerations for pelvis/hind limb radiography Safely position patient for various views Show an understanding of: Where to measure & center of primary beam Radiographic margins Patient positioning Use of non-manual restraint Distinguish & identify normal pelvis/hind limb anatomy

Skeletal Anatomy Review

Review: Pelvic Anatomy

Pelvis: General Considerations Anatomy: Half of femoral head should be in the acetabulum Femoral heads should be rounded and smooth Femoral neck should be smooth with no remodeling Views: Dorsal recumbency for pelvis (V/D) and femur (CrCa) Lateral recumbency for lateral view

Pelvis Positioning Dorsal recumbency: Used for proximal hind end

The Pelvis: Standard Positions Lateral Ventrodorsal Extended Ventrodorsal Frog-Leg

Pelvis – Lateral View Positioning: Affected limb down Slightly cranial Contralateral limb slightly ____________ Foam wedge/block under contralateral limb will help keep it parallel to IR Will have slight _________________ due to closer proximity to x-ray tube Superimposition! Forelimbs cranial

Pelvis - Placement Measure at thickest part Central beam: Usually greater trochanters Central beam: Coxofemoral joint Margins: Cranial to wings of __________ Should see at least one ______________ vertebrae Include 1/3 of femur

What are we looking at?

Pelvis – V/D Frog-Leg View Used when extended-hip view is too painful/ will not be tolerated Suitable for pelvic trauma NOT for _______ _________________ Hind limbs flexed normally Usually 45-90 degrees to spine Possible positioning technique Symmetry! If one ob. foramen is larger: that side is too high

Pelvis – Ventrodorsal Extended-Hip Standard for hip dysplasia evaluation Requires symmetry & precision Sedation is generally required (OFA certification). Positioning: Dorsal recumbency Rotate femurs medially Patellae are pointing upwards Tape together at the level of the ____________ Lower limbs until resistance is felt Whole body should be in straight line Other considerations: Keep cranial part of animal straight as well

Pelvis: V/D Hip Extended

Acetabular Fracture

V/D Hip (Extended) Normal view to evaluate hip dysplasia Definition: Abnormal development of the femoral joint, resulting in a lack of conformity between the acetabulum & femoral head