Equine Appendicular Radiology
Nancy E. Love DVM, Dip.ACVR
Getting Started
• Knowledge of normal anatomy is PARAMOUNT!
• Knowledge of radiographic conventions is necessary
• Consistency is your friend• Learning this now will make life in the
clinic (and ultimately practice) soooo much easier!
Radiographic PositioningNaming the Views
• Can be confusing – Take the time to understand or equine
radiology will remain frustrating and difficult to understand
• YOU SHOULD BE ABLE TO: – IDE�NTIFY THE VIEW– DESCRIBE HOW IT WAS POSITIONED– IDENTIFY MEDIAL AND LATERAL BORDERS
• and where markers should be located
Radiographic PositioningNaming the Views
• ALL radiographs are named using the direction of the beam as it leaves the x-ray machine ---> passes through the patient ---> reaches the film
• There is a convention for extremities– Proximal to and including the radiocarpal and tibiotarsal
joints - use the terms CRANIAL and CAUDAL– From the carpus and tarsus distal to the radiocarpal and
tibiotarsal joints use the terms DORSAL and PALMAR (forelimb) or PLANTAR (hindlimb)
– PROXIMAL and DISTAL are also used when describing direction on the extremity
Radiographic PositioningForelimb
ForelimbShoulder 1 view LatElbow 2 views CrCd, LatCarpus 5 views DP, Lat, Flex Lat, DLO, DMO
ShoulderShoulderLateral viewLateral view
(Medial to lateral)(Medial to lateral)
ElbowElbowCC or CC or CrCdCrCd viewview(Cranial to caudal)(Cranial to caudal)
ElbowElbowLateral viewLateral view
(Medial to lateral)(Medial to lateral)
Lateral Medial
Marker is LATERAL
Accessory carpal bone
CarpusCarpusDP viewDP view
(Dorsal to (Dorsal to PalmarPalmar))
AnatomyLateral - Accessory carpal bone
CarpusCarpusLateral viewLateral view
(Lateral to Medial)(Lateral to Medial)
Marker is DORSAL
CarpusCarpusFlexed Lateral ViewFlexed Lateral View
(Lateral to Medial)(Lateral to Medial)
Intermediate carpal boneRadial carpal bone
Marker is DORSAL
AnatomyIntermediate carpal bone is more proximal
than radial carpal bone
Medial Lateral
Marker INCORRECTShould be at LATERAL aspect of limb (palmar)
60º off dorsal OR
30º off lateral
Anatomy
Lateral - Fourth carpal bone and MC IV have a “stairstep” appearance- Accessory carpal bone is NOT superimposed with the carpus
MCIV
C4
Accessory
CarpusCarpusDLO viewDLO view
((Dorsolateral Dorsolateral -- palmaromedial palmaromedial oblique)oblique)
MedialLateral
C2
MCII
Accessory
CarpusCarpusDMO ViewDMO View
((Dorsomedial Dorsomedial -- palmarolateral palmarolateral oblique)
Marker is LATERAL
60º off dorsal OR
30º off medial
oblique)
AnatomyMedial - Second carpal bone and MC II are superimposedAccessory carpal bone is superimposed with the carpus
Radiographic PositioningHindlimb
HindlimbHip Requires anesthesiaStifle 3 views CdCr, Lat, DMOHock 4 views DP, Lat, DLO, DMO
StifleStifleCC or CC or CdCrCdCr viewview(Caudal to Cranial)(Caudal to Cranial)
Lateral Medial
PatellaMedial tibial eminence
AnatomyLateral - Patella, FibulaMedial - Medial tibial eminence is larger
StifleStifleLateral viewLateral view
(Lateral to Medial)(Lateral to Medial)
Cassette is too low in this example. You must really push cassette high into flank!
Tarsus Tarsus (Hock)(Hock)DP viewDP view
(Dorsal to plantar)(Dorsal to plantar)
Lateral Medial
Marker is LATERAL
Calcaneus
AnatomyLateral - Calcaneus
Tarsus Tarsus (Hock)(Hock)Lateral viewLateral view
(Lateral to Medial)(Lateral to Medial)
Marker is DORSAL
Tarsus Tarsus (Hock)(Hock)DLO viewDLO view
((DorsolateralDorsolateral -- plantaromedialplantaromedial oblique)oblique)
Medial Lateral
60º off dorsal OR
30º off lateral
Marker is LATERAL
Lateral - Fourth tarsal bone and MC IV have a “stairstep” appearance- Calcaneus is NOT superimposed with the tarsus
Medial - Medial trochlea does NOT have a distal “hook”
“Stairstep” at T4 & MT IV
Calcaneus
Anatomy
MedialLateral
60º off dorsal OR
30º off medial
Marker is LATERAL
Medial - Second tarsal bone and MT II superimposedLateral - Large “hook” distal aspect of lateral trochlea
Lateraltrochlea
No “stairstep” between T1/T2 & MTII
Tarsus Tarsus (Hock)(Hock)DMO viewDMO view
((DorsomedialDorsomedial -- plantarolateralplantarolateral oblique)oblique)
Anatomy
Radiographic PositioningEither Limb
Either Limb
Metacarpus 4 views DP, Lat, DLO, DMOFetlock 5 views DP, Lat, flex lat, DLO, DMOPastern 4 views DP, Lat, DLO, DMOFoot (P3) 2 views DP, LatNavicular bone 5 views 60ºDP, Lat, 0ºDP, 30ºDP, DP-DDO
Metatarsus 4 views DP, Lat, DLO, DMO
MetacarpophalangealMetacarpophalangeal Joint (Fetlock)Joint (Fetlock)DPDP
(Dorsal to (Dorsal to palmarpalmar))
Marker is LATERAL
Metacarpophalangeal Metacarpophalangeal Joint (Fetlock)Joint (Fetlock)LateralLateral
(Lateral to Medial)(Lateral to Medial)
Marker is DORSAL
MetacarpophalangealMetacarpophalangeal Joint (Fetlock)Joint (Fetlock)Flexed LateralFlexed Lateral
(Lateral to Medial)(Lateral to Medial)
Flexed lateral views are typically made for the forelimbs ONLY
Sagittal ridgeMarker is DORSAL
AnatomyThe sagittal ridge is less opaque and more dorsally
located than the medial and lateral condyles
MetacarpophalangealMetacarpophalangeal Joint (Fetlock)Joint (Fetlock)DLODLO
((DorsolateralDorsolateral to to palmaromedialpalmaromedial oblique)oblique)
Medial Lateral
Marker INCORRECTShould be at LATERAL aspect of limb (palmar)
35º from dorsal OR55º from lateral
Lateral Medial
Marker is LATERAL
35º from dorsal OR
55º from medial
MetacarpophalangealMetacarpophalangeal Joint (Fetlock)Joint (Fetlock)DMODMO
((DorsomedialDorsomedial to to palmarolateralpalmarolateral oblique)oblique)
Lateral
Accessory carpal bone
Medial
MetacarpophalangealMetacarpophalangeal BonesBonesDPDP
Dorsal to Dorsal to palmarpalmar
Study is positioned the same way forMetatarsophalangeal bones
Metacarpophalangeal Metacarpophalangeal BonesBonesLateralLateral
Lateral to medialLateral to medial
Study is positioned the same way for Metatarsophalangeal bones
MetacarpophalangealMetacarpophalangeal BonesBonesDLODLO
((DorsolateralDorsolateral toto palmaromedialpalmaromedial oblique)“Stairstep” betweenC4 and MC IV - has tobe a DLO view
LateralMedial
oblique)
Study is positioned the same way forMetatarsophalangeal bones
MetacarpophalangealMetacarpophalangeal BonesBonesDMODMO
((DorsomedialDorsomedial toto palmarolateralpalmarolateral oblique)NO Stairstep” betweenC2 and MC II - has tobe a DMO view
MedialLateral
oblique)
Study is positioned the same way forMetatarsophalangeal bones
Distal Phalanx and Distal Phalanx and Navicular Navicular BoneBone60º DP60º DP
(Dorsal to (Dorsal to palmarpalmar oblique)oblique)
This view is also used for the 60º DP of the navicular bone. Increased collimation and a darker technique is required.
Distal Phalanx andDistal Phalanx and NavicularNavicular BoneBoneLateralLateral
(Lateral to medial)(Lateral to medial)
Distal Phalanx andDistal Phalanx and NavicularNavicular BoneBone30 30 -- 45º DP45º DP
Upright pedal viewUpright pedal view
NavicularNavicular BoneBoneSkylineSkyline
((DorsoproximalDorsoproximal to to palmarodistalpalmarodistal oblique)oblique)
Flexor eminence
“Wing” of P3
Generally move the heel to the back edge of the cassette holder