STEEPLECHASE RADIOGRAPHY Flashcards
Overexposure
- Black
- High mAs, high kV
Underexposure
- Too white
- Low mAs, low kV
Radiolucent
- Black - radiation passes through
- Gas = black, low atomic no. + specific gravity, does not absorb as many photons
- Fat = lighter grey
- Fluid = shades of grey
Radiopaque
- White - inc absorption of radiation, less radiation passes through to detector
- Bone - high atomic no. + specific gravity, absorbs more photons
- Metal
Radiographic report
- Description - signalment + Hx, area imaged, projections
- Quality - exposure, positioning, technical faults
- Dx - description of image, identify variation from normal, summary of findings
- DDx - prioritise list - most sig, incidental findings
- Recommendations - imaging, Sx, Dx, ongoing managmenet
Radiographic interpretation - what to comment on
- P - positioning
- C - centring
- C - collimation
- E - exposure
- L - labelling
- A - artefacts
- Pink camels collect extra large apples
Positioning
- Area of interest
- Projections - e.g. lateral, R/L
- Lying on back = VD
- Sternal = DV
- Thoracic distal limb - radius/ulna = CC, craniocaudal
- Hindlimb = dorsal/plantar/palmar
- Standard views
- Standard pos
- Standard exposure settings
- Orthogonal view - 90 degree, prevent twisting/minimise geometric distortion
- Magnification
- Centring
- SI loops v mobile + easily displaced
Centring
- Anatomical area of interest using bony landmarks
- Allows close collimation to avoid scattering
- Cross on light diaphragm when collimator light on
Collimation
- Reduce radiaiton dose, scatter + improves contrast + image quality
Comment on exposure
Underexposed
Labelling
- L/R marker
- Patient name + date
Lateral views
- Rostral part of animal to viewer’s left
Ventrodorsal/dorsoventral
- Rostral part of animal pointing up + left of animal to viewer’s right
Lateromedial/mediolateral extremities
- Proximal limb up
- Cranial/dorsal limb to viewer’s left
Craniocaudal/caudodorsal extremities
- Lateral aspect of limb to viewers left
Artefacts
- Incorrect/no labelling
- Poor positioning
- Poor collimation
- Movement blur
- Fogging
- Double exposure
- Radiopaque artefacts on patient - mud, wet coat, syringe under patient
Inc size
- Hypertrophy
- Hyperplasia
- Neoplasia
- Torsion
- Cystic change
- Compare size to another structure/fixed landmark e.g. liver enlargement if extended costal arch, comparing kidney to lumbar vertebrae
Dec size
- Atrophy
- Hypoplasia
- Congenital anomaly
Localised/diffuse shape
- Neoplasia
- Necrosis
- Ulceration
- Physiological enlargement e.g. blood in spleen, uterus preg, aerophagia in stomach
- Pathological enlargement - neoplasia
Inc no.
- Accessory ossification centre
- Congenital anomaly
Dec no.
- Congenital anomaly
Inc opacity
- Calculi
- Mineralisation
- Fluid/ST in gas-filled structure
- FB
- Metallic opacity
Dec opacity
- Abnormal gas
- Osteopoenia (dec bone density)
Dec margination
- Periosteal reaction
- Protruding mass
- Free abdominal fluid -> loss in serosal detail
- Young + emaciated animals have poor serosal detail
Positioning
- This is a right lateral thorax of a skeletally mature dog
- The animal is not positioned straight. The forelimbs are not parallel causing rotation of the spine and thorax which can also be seen by the ribs not being superimposed. The forelimbs should also be extended forwards to avoid superimposition of the soft tissue of the legs over the cranial thorax.
Centring
- The image is centred too far caudally resulting in the mid point of the thorax not being in the centre of the image.
Collimation
- The collimation should include the thoracic inlet and caudal rib, and both dorsal and ventral skin edges. In this image the collimation is too wide ventrally and cranially. Some of the last rib is missing. This will be due, in part, to the incorrect centring.
Exposure
- The exposure of the image is sufficient such that the image is of diagnostic quality.
Labelling
- The right marker is just present but not fully in the image so its position could be improved. No patient details are apparent but they may be stored on the file if this is a digital image.
Artefacts
- There is artefact from dirt on the coat ventrally. Geometric distortion is present due to the limbs not being kept parallel but this does not affect the interpretation of the image as such.
Displacement of position
- Torsion
- Ectopia
- Hernia
Shoulder
- Mediolateral + caudocranial
Lateral thoracic
- 1y beam centred over mid thorax
- 1y beam collimated to include: manubrium/thoracic inlet, last rib, dorsal + ventral skin edges
Dorsoventral thoracic
- 1y beam centred over mid thorax
- 1y beam collimated to include manubrium/thoracic inlet, last rib, lateral skin edges
Craniocaudal elbow
- 1y beam centred midway between humeral condyles
- 1y beam collimated to include: 1/3 way along radius/ulna distally, 1/3 way along humerus proximally + lateral skin edges
Mediolateral elbow
- 1y beam centred over humeral condyle
- 1y beam collimated to include: 1/3 of way along radius/ulna distally, 1/3 way along humerus proximally + tight to the lateral skin edges as possible w/o compromising the imagine
Lateral abdominal
- 1y beam centred over mid abdomen/last rib
- Centre midway between spine + ventral aspect of body
- 1y beam collimated to include: entire diaphragm, pelvic outlet, dorsal + ventral skin edges
Ventrodorsal abdominal
- 1y beam centred midline caudal to last rib
- 1y beam collimated to include: entire diaphragm, pelvic outlet + lateral skin edges
Mediolateral stifle
- 1y beam centred distal to femoral condyles
- 1y beam collimated to include: distal 1/3 of femur + proximal 1/3 of tibia
Ventrodorsal hip
- 1y beam centred on pubic symphysis/midline between hips
- 1y beam collimated to include: lateral skin edges, cranially to iliac crests, caudally to mid femur
Elbows
- Mediolateral (neutral, flexed, extended)
- Craniocaudal
Carpus
- Mediolateral (flexed + extended)
- Dorsopalmer
Distal limb (thoracic)
- Dorsopalmer
- Mediolateral splayed digits
- Oblique
Hips
- Ventrodorsal + lateral pelvis
Stifles
- Mediolateral
- Caudocranial
Hocks
- Mediolateral (flexed + extended)
- Plantarodorsal
Distal limb (pelvic)
- Plantarodorsal
- Mediolateral splayed digits
- Oblique
Rules of thumb - limb imaging
- Two orthogonal projections at right angles
- Include joint above + below Fx
- Use contralateral limb for comparison
- Include 1/3 long bone proximal + distal to joint
Limb imaging exposure criteria
- Should be able to assess bone + ST
- See trabecular detail in bones
- Cortical bone = dense white
- ST = grey tones
- Underexposure = bone homogenous white
Limb - approach to evaluation - Soft tissue
- Localisation
- Change in tissue mass
- Opacity - around bone
Limb - approach to evaluation - bone
- Lesion description
- Location within bone
- Epiphysis, metaphysis, diaphysis
- Periosteum, cortical bone, endosteum, trabecular bone, medullary cavity
- Opacity
- Margins
- Joint involvement
- ST involvement
Limb - approach to evaluation - joints
- Alignment of bones
- Character + distribution of bony lesion
Soft tissue evaluation - change in tissue mass
- Diffuse inc - SC fluid, oedema, lymphoedema, cellulitis, neoplasia, emphysema (inc air)
- Localised inc - abscess, cyst, haematoma, neoplasia, assess adjoining bony structures for neoplasia
- Atrophy - disuse, neurogenic, myositis, weight loss
Soft tissue evaluation - changes in opacity, inc in opacity (more white)
- Artefacts - dirt, foreign material
- Calcification - calcinosis cutis (Cushing’s/hypoadrenocorticism), calcinosis circumscripta, tendon mineralisation, metastatic (calcium phosphate) mineralisation
- Ossification - extraskeletal osteosarcoma, myositis ossificans
- Radiopaque FB
Soft tissue evaluation - changes in opacity, dec in opacity (more black)
- Fat - lipoma
- Gas - puncture, sinus, open Fx
- Facial planes - radiolucent lines gas lines between
- Inc ST opacity
- Calcinosis circumscripta
Describing lesions - bone
- Monostotic - lesion present in one bone, e.g. osteosarcoma
- Polyostotic - lesion present in many bones, e.g. multiple myeloma
- Focal lesion present in specific bone region e.g. metaphysis/diaphysis
- Generalised - involving all bones, often a metabolic condition
- Symmetrical - present on both sides of a bone e.g. metaphyseal osteopathy
- Asymmetrical - present on one side only e.g. from premature closure of a growth plate due to trauma
- Physis - only present in immature animals where growth plate has not closed, relevant for salter harris fracture classifications
Bone lesion location
- Areas of each bone - periosteum, cortex, medullary cavity, physes
- Proximal or distal? etc - planes
New bone formation
- Response to injury/insult or neoplasia
Internal
- Inside medullary cavity - trabecula, endosteum
- Reactive - inc thickness of normal trabeculae, organised homogenous appearance: panosteitis
- Neoplastic - non-homogenous - osteosarcoma, chondrosarcoma
Periosteal
- External to bone
- As result of injury/insult
Panosteitis - painful inflam of outer surface or shaft of long bone
Periosteal reactions
(In order of aggression)
- Smooth/solid
- Laminated
- Sunburst
- Codman’s triangle
- Amorphous
Periosteal reaction - smooth
- Slow lifting of periosteum over period of time
- New bone laid down below
- Solid + uninterrupted change
Periosteal reaction - laminated
- Slower process
- More aggressive than smooth
- Periosteum lifted in interrupted fashion resulting concentric laminated layers - onion skin
- Layers of periosteum + cortex
Periosteal reaction - sunburst
- Highly aggressive process
- Lesion is growing rapidly that periosteum doesn’t have time to lay down layer of new bone
- Sharpey’s fibres stretched out perpendicular to bone then ossify
- Osteosarcomas
Periosteal reaction - Codman’s triangle
- Rapid process
- Cortical destruction present
- Edges of periosteum raised + ossify forming triangle w/ surface of bone - flap/angle against bone
Periosteal reaction - amorphous
- Not technically periosteal reaction
- Neoplastic new bone seen beyond destroyed periosteum
- ‘Cotton wool’ like
- Highly suggestive of osteosarcoma (almost always neoplastic)
- Solid periosteal reaction
Lamellated/laminated periosteal reaction
Sunburst periosteal reaction
Codman’s periosteal reaction
Types of bone loss
- Lysis, loss = radiolucent
Order of aggression - - Focal
- Geographic - least aggressive + slower growing lesions - single large radiolucent lesion w/ sclerotic rim + cortex destruction
- Moth-eaten - multiple separate foci or lysis, more ill-defined + transitional zone between affected + non-affected bone
- Permeative - most aggressive + rapidly growing lesions, numerous areas of lysis w/ poorly defined borders + wide + indistinct transition zone
Inc bone opacity
- Real - new bone production
- Artefactural - superimposition - of Fx = poor positioning
Dec bone opacity
- Bone loss = radiolucent
- Real = generalised of focal bone loss
- Artefactual - superimposition gas, focal reduction of ST
Osteopenia
- Generalised bone loss - imbalance between bone formation + resorption
- Generalised = dietary, disuse, hormonal deficiency, congenital
- E.g. Nutritional 2y hyperparathyroidism, Fx, endocrine, Cushing’s, diabetes, pituitary dwarf, rubber jaw congenital disease - affects PO4^3-
- Localised = pressure - from neoplasia, infection
Osteoporosis
Bone atrophy
Osteomalacia
- Reduction bone mass
- Failure of mineralisation of newly formed bone
Geographic lysis
Permeative lysis
Moth-eaten lysis
Joint changes - what should be assessed
- Joint space
- Joint margins
- Subchondral bone
- Loose bodies
- Alignment of articular surfaces
Causes of increased width of joint space
- Skeletal immunity
- Synovial effusion
- Joint laxity
- Joint incongruity
- Thickened cartilage
- Destruction of subchondral bone
- Inc width of joint space
- Ligamentous tear to stifle
There should be radiolucent fat pad, its absence suggests inflam
Osteophyte
- Outgrowth of bone at margin of articular surface of synovial joint
- E.g. New growth, osteoarthritis
Enthesophyte
- Focal proliferation of new bone to form a spur at an attachment of ligament
- E.g. Trauma
Calcification
- Loose fragment of calcified tissues
- E.g. Joint mice
Osteophyte
Subchondral bone abnormalities
Irregularities of the margin due to OCD, sepsis, or immune-mediated joint disease
Defect in subchondral bone due to OCD
R Lateral view of cat hock
- ST - more radiopaque, inc opacity, inc mass/swelling
- Bone - mid-diaphyseal transverse/oblique Fx, slightly commuted (more than two bits)
- Oblique Fx of fibula
- Lysis of bone in prox epiphysis/metaphysis region, loss of opacity + moth-eaten appearance, poor margins in transition zone = patho, bone neoplasia, tibia not got much chance of Fx
- ST hard to evaluate
- Moth-eaten bone, a lot of lysis but clear transition zone in proximal part of bone, cotton wool appearance on periosteum, neoplastic process, no change across joint space
Elbow
- ST - slight swelling, not marked
- Bone - enthesophytes around edges of bone - calcification in ST - within tendon/ligament, osteophytes around margins of bone = irregular border of bones
- Joint - margin/space = irregularity, one side wider than other, asymmetry, narrowing of joint space at radial head
- Osteoarthritic changes (often due to elbow dysplasia), early arthritic changes
- ST - not much on foot, slightly radiopaque, digit 5, thickening around toe, inc ST mass
- Bones - fabellas present on top of toes, margins abnormal - oesteophytes growing off margins (articular types)
- Joints - space - narrower compared to other toes
- Old Collie w/ bad arthritis in feet
Head radiography indications
- Deformity, swelling, or discharging sinus
- Trauma - skull Fx
- Ear disease - tympanic bullae
- Exophthalmos (bulging eyes) or Horner’s syndrome (less sensitive - US/CT)
- Pain in head area
- Problems w/ jaw mobility/teeth - dislocations, diff opacities
- Nasal or nasopharyngeal disease
- Dental disease
Dolichocephalic - long-nosed skull
Lesion orientated view of swelling
Oblique lateral views - avoid superimposition
Nasal cavities
Dorsoventral intra-oral (DVIO) - x-ray plate in mouth on top of tongue to see through nose, septal deviation
Ramus of mandible, mandibular teeth
Ventrodorsal intra-oral - plate in mouth, x-ray through mandible
Nasal cavities more caudally + laterally
Ventral 20° rostral-dorsocaudal oblique
Tympanic bullae (dog)
Rostrocaudal open mouth
Tympanic bullae (cat)
Rostral 10° ventral-caudodorsal oblqiue
Skyline calvarium + frontal sinus
Rostrocaudal + caudodorsal closed mouth
Head abnormal findings
- Fx - cranium, maxillae, mandible, zygomatic arch
- Congenital/developmental conditions
- Neoplasia - cranium, maxillae, mandible
- Craniomandibular osteotomy (lion jaw in Westies) - periosteal reaction on mandibles, tympanic bullae, fluffy
- Ear disease - changes in bullae
Hydrocephalus - no bony markings on cranium
Dental indications
- Dental trauma - chewing
- Jaw Fx
- Anodontia (absence of teeth)
- Retained deciduous dentition (below gum/crypt)
- Periodontal disease - abscess?
- Endodontic disease
- Extraction of teeth
- Malocclusions
- Nasal discharge
- Swellings, cysts, neoplasms
Dental radio - bisecting angle technique (lateral)
- X-ray beam = perpendicular to bisecting angle - creates shadows of teeth
Incisors
- Bisecting angle
- Dog in sternal - maxilla radiographed; or dorsal - mandible radiographed
- Sensor sits in mouth w/ incisor teeth towards edge
Maxillary canine teeth
- Lateral view + bisecting angle from rostral direction, plate for parallel does not fit as hard palate in the way
- Sternal
- Sensor placed flat on plate w/ rostral edge level w/ canine tooth
- X-ray beam directed from ipsilateral side to ‘cast the shadow’ of the canine tooth onto the sensor
Mandibular canine teeth
- Lateral/occlusal view - bisecting angle
- Dorsal recum
- Sensor placed on premolar teeth, w/ rostral edge of sensor level w/ canine teeth (smaller dogs - sensor can rest on tip of cusp of canine teeth)
- X-ray directed from lateral aspect + w/ maxillary canine tooth
Maxillary canine fourth premolar (upper carnassials/108, 208)
- Bisecting angle
- Sternal
- Sensor resting on plate + 4th premolar tooth (inside edge resting on palate, outside edge resting on main cusp of 4th premolar tooth)
- X-ray beam directed towards same side as tooth imaged
Parallel dental technqiue
- For caudal mandibular premolars + molars
- Long axis of tooth + sensor are parallel + x-ray beam is at 90 degrees to sensor + long axis of tooth
Mandibular first molar
- Parallel
- Sensor placed into back of mouth w/ cheek teeth parallel
- X-ray beam directed parallel to sensor
- Tooth elongation - x-ray beam directed at 90 degrees to long axis of tooth
- Move tube head more medially
- Tooth shortening - x-ray beam directed at 90 degrees to film
- To make roots longer, move tube head more laterally
Dental radio interpretation
- Enamel - how radiopaque tooth looks on crown
- Dentine - radiopaque
- Pulp cavity - radiolucent
- Alveolar bone - bone surrounding tooth
- Lamina dura - radiopaue
- Periodontal ligament space - radiolucent
- Mandibular canal
- Alveolar bone height should extend to just below enamel/cementum junction
- Feline odontoclastic resorptive lesions (FORL)
- Red, raised granulation or premolar, probe = painful -> bleed of crown
Periodontal disease - periapical abscess, loss of bone
Neck + spine radio indications
- Mono-, para- + quadriplegia
- Paresis or paraparesis
- Ataxia - bilateral may have bilateral cruciate disease
- Spinal pain
- Stiffness
- Suspected vertebral deformities
- Sinus tracts in lumbar region - FB
Neck + spine - lateral
- Spine parallel to table top
- Foam wedge - under neck: between limbs, under lumbar spine; cervical spine: under nose
- Forelimbs - servical spine drawn caudally
- Should have super imposition of: wing of atlas, transverse processes of C6, equal in size
- Rib origins
- Lumbar transverse processes
- Wings of ilia
Neck + spine - ventrodorsal
- Dorsal recum
- Support w/ radiolucent trough
- Foam wedges to prevent rotation
- Should have oval central opacities of spinous processes, equally-sized transverse processes
Centring - upper cervical
C2 - C3
Centring - lower cervical
C5 - C6
Centring - mid-thoracic
T8
Centring - thoracolumbar junction
T13 - L1
Centring - mid-lumbar
L4 - L5
Centring - lumbosacral
L7 - S1
Spinal radiograph interpretation
- Vertebral alignment
- Length, shape, opacity, vertebral bodies - should be square
- Contour + opacity of vertebral end plates - where vertebrae meet at disc, changes in opacity e.g. disc spondylosis
- Intervertbral disc space width + opacity
- Articular process joints
- Paravertebral ST
(MRI)
Abdo radiography indications
- Abdo distension, enlargement
- Investigation of palpable masses, enlargement
- Weight loss - wellbeing screening
- Abdo pain
- Screening for neoplasia - staging, may be 2y in abdo
- Screening following trauma - look for H+/fluid
- GI signs
- Urinary signs
- Repro tract examination
Abdo exposure
- Low kV + high mAs -> max contrast due to ST organs, fat + mesentery
Abdo positioning
- Main orthogonal views = ventrodorsal (in sternal), organs spread out + Right lateral
- +/- Left lateral
(Dorsoventral, decubitus lateral)
Stomach
- Cranial abdo, caudal to liver
- Opacity depends on content e.g. food, gas, fluid
- Gas distribution - depends on position
GDV - looks like smurf!!!
SI - ileus
- Abnormal inc in diameter = dilation
- > 1.6 x height lumbar vertebrae L5
- Dilated loops containing fluid, gas or mixture
- Assess no. dilated loops + position
SI - obstructive (mechanical) ileus
- FB - dilation of SI proximal -> nothing gets past
- Neoplasia
- Intussusception - teloscoping, young puppies - worm burden
SI - functional (paralytic) ileus
- Hypokalaemia
- Peritonitis
- Inflammation (enteritis)
LI
- Relatively consistent in appearance
- Filled various amounts - heterogenous faecal material
LI - constipation
- LI dilation w/ opaque faecal material
- Megacolon - esp cats
- Bone ingestion - dogs, radiopacities
LI - ventral displacement
Enlargement of kidney, sub-lumbar LN, retroperitoneal space
LI - dorsal displacement
Enlarged prostate, uterus (pyometra), bladder
GIT - positive contrast studies
- After plain radiography
- More opaque than ST
- Barium sulphate - PO/per rectum
- Good at coating mucosa
- Contraindication if aspiration risk e.g. megaoesophagus
Generalised hepatomegaly
- Caudal displacement of pylorus
- Extension beyond costal margin (gastric access)
- Non-specific finding
- US-guided FNA needed for Dx
Liver neoplasia
- Generalised hepatomegaly
- Cranial abdo mass
- Haemoabdomen
Spleen neoplasia
- Variable sized mid abdominal ST mass
- Haemoabdomen - haemangioma/haemangiosarcoma, haematoma
Portosystemic shunt
- Small liver = microhepatica
- Abdo US + doppler required
Urinary tract organs
(US better)
- Kidneys - size, shape, opacity + position, no information on func, length 2.5 - 3.5 x L2 (dog) / 2.4 - 3.0 x L2 (cat) - VD
- Ureters + urethra - need contrast study
- Bladder - location, size, shape, no info on luminal surface bladder wall
- Prostate (dog) - size + location, height not more than 70% height pelvic brim
Sludgy bladder - rabbits, too much Ca2+ in diet
Urinary tract - contrast studies
- Double contrast cystogram
- Retrograde urethrogram
- Retrograde vaginourethrogram
- Intravenous urography
- Positive contrast = water-soluble iodinated contrast material = conray or omnipaque
- Negative contrast = air (pneumocystogram) or CO2
- Enema essential
- Check renal parametets
- Admin IVFT
- GA, don’t withhold water
Urinary tract contrast studies - views
- Plain lateral + VD
- Lateral + VD immediately post-injection and at 5 min + 10 min
- Lateral at 15 min post injection
Urinary tract - contrast study indications
- Internal architecture kidneys = cystogram
- Delineates ureters - where enter bladder
- Ectopic ureter Dx - cystography too sensitive
Incisor malocclusion
Rabbit
- No obvious spinal abnormalities or arthritic changes seen (but VD view of caudal spine, hips and hind legs under sedation would be required to confirm this)
- No uroliths visible
- Intestines diffusely distended with gas but no gastric dilation/bloat
- Ileus - gut stasis
Rabbit
- Radiopaque substance in the bladder, seems to be a ‘sludgy bladder’ because the mineral has settled in the ventral aspect of the bladder and has no defined circular outline to suggest a urolith.
- No uroliths seen in kidneys/ureter/urethra/bladder
Rabbit
- Bronchial and alveolar infiltrates bilaterally in the dependent portions of the lungs.
- Caudal lung lobes appear hyperinflated with flattening of the diaphragm
- Heart and pulmonary vasculature are not well identified.
- Right 8th and 9th ribs are fractured
- Indicate severe pneumonia.
Rabbit
Rabbit
Normal teeth - molars top + bottom, jagged points, cheese grater surface due to all grass + hay consuming
Rabbit
