Radiology 10/7
Terms
undefined, object
copy deck
- slow speed
- have increased definition/detail-need to have increased radiation exposure
- (+) Ortolani Sign
- increased laxity felt when try to "pull" femoral head out of acetabulum
- Name the 3 things X-rays may do
- 1. scatter off the object, 2. get absorbed by the odject, 3. pass through the object
- Non-screen film
- don't have screens or film cassettes, x-rays directly cause a latent image, no visibly light
- non-invasive:
- swimming, phyical therapy, lose wt., acupuncture, anti-inflammatory meds, and nutraceuticals
- film cassettes
- rigid film holders, protect the film from external light damage
- flexion tests
- very lame/tender when extend.flew shoulder
- If metal-
- white, no x-rays get through
- what are the 2 types of grids?
- focused; unfocused or unparallel
- grid cutoff
- when the x-ray tube is not in the range, a decrease in the number of x-rays that reach the film near the periphery due to the grid absobing the x-ray
- 36-40 inches
- the distance the grid needs to be this from the x-ray tube
- OCD of stifle and hock
- don't need surgery--heal on it's own may develope some DJD whether they have surgery or not
- Intervertebral disk disease
- ruptured disk, protrusion, erniation, extrusion, slipped disk
- paresis
- weakness; decreased proprioception; when press on lower back may sit
- phosphor layer thickness
- increased thickness leads to increased x-ray absorption and increased visible light emission from crystals
- Hyperesthesia
- pain; muscle spasms, cervical rot signature, resents manipulation, acute or chronic
- grid efficiency
- is determined by the ratio of the height of the lead strips to the distance between them
- OCD is
- an idiopathic disease, problems in the conversion of cartilage to bone in young animals
- ventral laminectomy
- surgery for paralysis of cervical
- unexposed AgBr crystals
- are washed off in the fixer solution wot give white/clear areas
- What are the 3 things screen layers need?
- higher levels of x-ray absorption, high levels if x-ray to light conversion with the correct energy and color for the type of film used, must have little to no "afterglow"
- hew theory;
- too much fluid in joint--leads to separation
- Where are there no disks?
- between C1-C2, S1-S2, S2-S3
- screens are classified according to what?
- speeds
- rare earth elements
- give off 4 times the amount of light photons than others; green light
- osteomyelitis
- bone infection
- Label for OFA
- Animal ID, date of birth, breed, date, owner ID, Vet ID
- the two phosphor type's are?
- Rare earth elements, calcium tungstate
- OCD
- osteochondrosis dessicans
- nutriceuticals
- medications used to help rebuld/heal cartilage- glucosamine
- screen speed ratings
- slow, medium or par, and fast
- bone tumors
- primary--start there, secondary--metastatic or started elsewhere and travelled
- wobblers syndrome
- dobermans condition where there is cervical instability and the disk tend to ave more movement than usual and tey are more apt to rupture
- Need two copies of radiograph-
- put in 2 films and increase kVp by 15%
- treatment for OCD
- rest, slow down growth, decrease calcium intake, nutriceuticals, surgery to remove flaps or mouse
- 5% is due to:
- the x-rays directly
- grid focus
- the name of the distance of the grid from the x-ray tube
- crystals size
- increase crystal size = more light given off
- Do not radiograph:
- females 3-4 weeks before and after heat-due to laxity caused by estrogen
- grid
- a series of lead strips on edge which only allow the primary x-rays which are traveling in straight lines reach the film
- grids
- help to reduce the amount of scatter radiation that reaches the film
- diskospondylitis
- infection of disk and the bone near it, seen with old male dogs
- AbBr layer
- are where the action occurs
- flexed lateral view-
- of the elbow is needed for certification of the elbows
- DJD
- degenerative joint disease
- metallic silver areas
- when in the dark room turn black in the developer solution
- early signs of hip problems:
- due to joint laxity/instability
- area where seldom see disk problems
- cranial/middle thoracic area
- Use a grid if:
- chest > 15 cm, any body part > 10 cm
- film composition
- polyester base in the middle, adhesive layers, emulsion of silver bromide crystals in gelatin layers, and protective coating
- latent image
- an image caused by a non-screen film
- HIp Dysplasia:
- malformation and degeneration of the coxofemoral joints, most comone diseases with large/gaint breeds, genetic and environment
- Treatment options
- non-invasive, invasive, prevention
- Diagnose Hip Dysplasia
- ventral dorsal radiograph
- osteomyelitis
- bone infections---bacterial of fungal
- non-screen films are
- sensitive to x-rays, use no screens and no cassettes
- potter-bucky diaphragm
- a device that moves the grid back and forth under the table
- prevention of OCD
- do not breed affected animals, do not breed affected animal's parents to each other again
- cuadal humeral head
- primary area of OCD affected in the shoulder
- which is more efficient? 10:1 or 5:1
- 10:1 grid
- spondylosis
- calcium "bridging" between adjacent vertebrae. Adds stability to area. See with older animals
- Name 5 things that can be seen on a shoulder radiograph:
- fluid in joint, fractures, tumors, bone infections, OCD
- pennhip technique
- put a decive b/w hips while dog on back, put inward pressure on hips to pull the femoral heads from sockets, >3mm
- nucleus pulposis
- gelatinous center that can protrude into the intervertebral canal and pinches the spinal cord
- back of cassette is made of?
- lead to decrease back scatter
- calcium tungstate
- when exposed to x-rays this will absorb photons and give off blue light
- hip joint
- the femoral head is held in the acetabulum by round ligaments, joint capsule, and muscle
- Radiograph signs of HIp dysplasia may:
- start as early as 4-9 months, start in adulthood, and never show signs
- screen speeds are
- inversley proportional to the exposure required to cause it to fluoresce
- elbow dysplasia's
- ununited anconeal process, fragmented coroniod process, OCD of medial humeral condyle
- If fat or muscle-
- grey areas, some x-rays get through
- What 3 things determine amoutn of x-rays
- 1. anything in beam's path, 2. how thick the object in the path is, 3. what the object is made of
- treatment for paralysis
- surgery
- prevention:
- genetics, environment
- medium or par speed
- most common type- gives good resolution with relatively low exposure
- shoulder x-rays
- label R or L, pull legs in opposite directions to avoid superimposition, use the standard mAs of 5
- what makes a disk herniate?
- 1.annulus fibrosis, 2. nucleus pulposis
- proprioception
- don't know where there feet are; may knuckle
- screen films are
- sensitive to visible light, use screens and cassettes
- abnormalites of hip leads to
- poor contact of femoral head to acetabulum, DJD, or irregular acetabulum and femoral head
- OCD of shoulder and elbow-
- need surgery
- paralysis
- paraplegic, quadraplegic, emergency situation
- dyes in the phosphor layer
- pigments tend decrease the lateral spreads of light so there is increased detail, need to use more x-rays
- If no object-
- black areas, all x-rays get through
- annulus fibrosis
- outer fibrous layer od disk dries out and cracks
- osteosarcoma
- tumors of the bone
- triple mAs when?
- to compensate for the x-ray absorption by the grid
- invasive:
- pectineus myotomy, triple pevic osteotomy, femoral head and neck excision, and total hip replacement
- name the 4 reasons for grid cutoff
- incorrect grid focus, improper centering of the grid beneath teh x-ray tube, tilting of the tube or the grid, focused grid upside down
- At least 24 months old
- OFA states that animals must be this before time of x-ray
- later signs of hip problems:
- due to DJD
- Iohexol or Omnipaque
- an iodine base dye injection used in a myelogram
- anomalies
- extra vertebrae, fused vertebrae, spina bilida, scoliosis
- Environments issues of HD
- slow down the rate of growth in breeds that are prone to it, start on adult food at 6mths old
- large crystals
- faster screens- less detail- high "grain"
- typical hip displasia signs:
- cow hocked, bunny hop, narrow rear end, difficuly rising or doing stairs, decreased activity, more lame after exercise
- If bone-
- whiter areas, few x-rays get through
- quantum mottle
- spotty or mottled appearance, fewer x-rays hit fewer crystals, decreased fluorescence, seen more with rare-earth screens
- radiograph of hips and pelvis show:
- fractures, tumors, dislocations, hip dysplasia
- processing
- turns the latent image into a visible image
- Radiographic signs dont't-
- alway's agree completely with the clinical signs
- typical case of OCD
- 5-10 mths old large/giant breed dogs, males, gradual or acute, lameness worse after exercise, lame-extend and tender-flew shoulder, 50% in both
- Name 5 things that cassettes are made of:
- Bakelite, aluminum, magnesium, carbon fiber, vinyle
- dorsal laminectomy
- surgery for paralysis of toracic lumber
- reflective layer efficiency
- reflects light made by phosphors back towards the film
- screen speed is affected by what 5 things?
- phosphor type, phosphor crystal size, phosphor layer thickness, dyes in phosphor layer, reflective layer efficiency
- The 3 clinical signs of Disk disease
- pain, paresis, paralysis
- Fast speed
- decreased exposure, poorer detail, able to penetrate thicker areas
- typical "screen film"
- uses 95% of our exposure on the film is due to visibe light
- Make sure screens are
- secure to the cassette, have good contact with the film, and the top screen is thinner than the bottom screen
- radiographic details are
- inversely proportional to screen speed. slow screens = more detail
- small crystals
- slower screens- more detail- low "grain"
- lines per centimeter
- if the grid is stationary more lines that are finer are less apt to show up on a radiograph
- AgBr + x-rays =
- ionization--Ag (metallic/black)...with non-screen films
- slow screen needs?
- a lot of exposure because tey give off less light
- non-screen films need:
- a lot more x-ray exposure, more time to expose them; dental films
- film cassettes
- keep the x-ray film in close contact with the screens, must be radiolucent
- What is the most common place of disk herniate?
- 15% cervical- dobermans, 85% caudal thoracic and lumbar- dachshunds, beagles, pekingese
- 8 things seen with elbow radiographs:
- fracturesof proximal radius/ulna and distal humerus; tumors, infections, dislocations, ununited anconeal process, fragmented coronoid process, OCD of medial humeral condyle, DJD
- treatment fo rpain and paresis
- cage rest, steriods, monitor, chiropractice, acupuncture
- crystals + x-rays=
- visible light
- AgBr + light =
- ionization--Ag (metallic/black)....with screens films
- fast screens need?
- much less exposure because they give off a lot of light
- fractures of the:
- distal scapula, and proximal humerus
- Joint mouse
- cartilage forms a flap which can break free and float in the joint, pain and DJD
- Genetics of HIp dysplasia
- breed normals to normals and make sure they also ave normal relatives
- myelogram
- inject iodine based dye called Iohexol or Omnipaque which will out line the "pinched" spinal cord
- fluoroscopy
- used to take "real time" radiographs, no x-ray film is involved, reverse from radiograph whites and blacks are reversed
- dog spine numbers
- C7, T13. L7, S3, Cd variable
- Intensifying screens
- sheets of luminescent phospor crystals on a cardboard or plastic base, need 2
- luxations
- dislocations or sederations (atlanto-axial, lumbo-sacral, Ileo-sacral)