Imaging Flashcards
What cause geometric distortions on a radiograph?
If the structure is not truly parallel to the film/detector
Structure towards the edge of the coli mated area
Reduce by GA, careful positioning and tight collimation
Mac line
Artifactual radiolucenct line
Pink camels collect extra large apples
Positioning Collimation Contrast Exposure Labelling Artefacts
What 5 thing should you describe on a radiographic lesion?
Number Size Shape Location Opacity
What should you assess on the soft tissues of a radiograph?
Swelling
Loss
What should assess on bones on a radiograph?
Alignment, shape, length Periosteal reaction Cortical lysis Defects Endosteal / medullary changes Physes
What should you evaluate in the joints on a radiograph?
Swelling / effusion
Subcontractors bone
Peri-articular changes
How much mineral loss is required to see a decrease in bone density on a radiograph and how long does this take to show?
30-60% mineral loss
Takes 7 days to show
What causes a localised reduction in bone opacity?
Neoplasia
Osteomyelitis
Bone cyst
What are the names of areas of focal bone lysis from least aggressive to most aggressive?
Geographic
Moth-eaten
Permeative
What are the descriptions of periosteal reaction from benign to aggressive?
Smooth Rough Brush border Pallisading Spicular Sun burst Amorphous
What are the radiographic signs of an aggressive bone lesion?
Long zone of transition
Active periosteal reaction
Destruction of the bone cortex
Soft tissue swelling
How can you categorise a lesion according to its distribution?
Monostotic Polostotic Focal Generalised Symmetrical Asymmetrical
What should you assess in joints?
Soft tissue swelling Joint space / width Subchondral bone opacity Osteophyte / enthesiophyte Peri-articular mineralisation
What lesions will produce sub-chondral bone defects?
Osteochondrosis Aseptic necrosis (femoral head) Septic arthritis Erosive arthritis (carpus / tarsus) Soft tissue neoplasia Trauma / avulsions Osseous cyst like lesions Very severe osteoarthritis
What should you look for in periarticular bone?
Enthesiophyte (ligaments) Osteophytes (joint capsule) Synovial osteochondroma (cats)
How can you assess stifle joint effusion?
Bulging of the caudal facial plane of the stifle
Cranial displacement of the infra-patella fat pad
soft tissue / fluid radiopacity in the joint space
What are the radiographic changes seen in osteoarthritis?
Soft tissue swelling / effusion Peri-articular new bone formation - osteophytes - enthesiophytes Reduced joint space Subchondral bone sclerosis Subchondral bone destruction
What are the predilection sites of osteochondrosis?
Caudal aspect of the humeral head
Medial humeral condyle
Lateral femoral condyle
Medial trochlear ridge of the talus
What are the predilection sites of osteosarcoma?
Away from the elbow
towards the knee
Proximal humerus
Distal radial and ulna
Distal femur
Proximal tibia
What structures can you assess on ultrasound in the shoulder?
Biceps tendon and sheath
Supraspinatus and infraspinatus muscles and tendons
What structures should you evaluate by ultrasound in the tarsus?
Common calcanean tendon
Gastrocnemius
Superficial digital flexor tendon
Biceps femoris + gracillus + semitendinosus
