Radiographic Critique Radiographic Critique of the Lower of the Lower ExtremityExtremity

Chapter 5Chapter 5

Foot (AP-Dorsoplantar)Foot (AP-Dorsoplantar)

ID requirements /marker /No preventable ID requirements /marker /No preventable artifactsartifacts

Contrast & density: soft tissue & bony Contrast & density: soft tissue & bony structures of footstructures of foot

Good penetration trabecular & cortical of Good penetration trabecular & cortical of phalanges, metatarsals & tarsals phalanges, metatarsals & tarsals

(55-65kVp)(55-65kVp)

Foot (AP-dorsoplantar)Foot (AP-dorsoplantar)

?true AP: 1?true AP: 1stst, 2, 2ndnd, & 3, & 3rdrd cuneiforms joints cuneiforms joints spaces open; with 2cm of calcaneus shown spaces open; with 2cm of calcaneus shown without talar superimposition and equal without talar superimposition and equal concavity on both sides of 1concavity on both sides of 1stst metatarsal metatarsal midshaftmidshaft

?leg, ankle, and foot aligned?leg, ankle, and foot aligned ? Rotated laterally the navicular tuberosity is ? Rotated laterally the navicular tuberosity is

shown in profile with the talus over the shown in profile with the talus over the calcaneuscalcaneus

? Rotated medially talus moves away from ? Rotated medially talus moves away from calcaneuscalcaneus

Foot (AP-dorsoplantar)Foot (AP-dorsoplantar)

? Tarsometatarsal & navicular-cuneiform ? Tarsometatarsal & navicular-cuneiform joint space openjoint space open

?long axis aligned?long axis aligned ? Proximal 2? Proximal 2ndnd & 3 & 3rdrd metatarsal bases in metatarsal bases in

center of field with proximal calcaneus, center of field with proximal calcaneus, talar neck, tarsals, metatarsals, talar neck, tarsals, metatarsals, phalanges, & surrounding foot soft tissuephalanges, & surrounding foot soft tissue

Foot (medial or internal)Foot (medial or internal)oblique positionoblique position

Determine ? Obliquity ( 30 or 45 degrees)Determine ? Obliquity ( 30 or 45 degrees) Low arch 30 degrees / high arch 45 degreesLow arch 30 degrees / high arch 45 degrees ?not rotated enough, 4?not rotated enough, 4thth & 5 & 5thth intermetatarsal intermetatarsal

joint spaces are closed with 4joint spaces are closed with 4 thth met base met base superimposed 5superimposed 5thth

?rotated too much, 4?rotated too much, 4thth & 5 & 5thth intermetatarsal joint intermetatarsal joint space is closed with 5space is closed with 5thth proximal met base proximal met base superimposed 4superimposed 4thth

?long axis aligned/ 3?long axis aligned/ 3rdrd met base in center of met base in center of fieldfield

Foot (lateral)Foot (lateral)

?true lateral: domes of talus are ?true lateral: domes of talus are superimposed, the tibiotalar joint is open & superimposed, the tibiotalar joint is open & distal fibula is superimposed by the posterior distal fibula is superimposed by the posterior half of the distal tibiahalf of the distal tibia

? Long axis of foot at 90 degree angle with ? Long axis of foot at 90 degree angle with lower leg and aligned with long axislower leg and aligned with long axis

?proximal metatarsals in center of field with ?proximal metatarsals in center of field with phalanges, metatarsals, tarsals, talus, phalanges, metatarsals, tarsals, talus, calcaneus, 1 inch of distal lower legcalcaneus, 1 inch of distal lower leg

Ankle (AP)Ankle (AP)

If rotated laterally or medially the medial If rotated laterally or medially the medial mortise is hiddenmortise is hidden

?tibiotalar joint open & tibia seen without ?tibiotalar joint open & tibia seen without foreshorteningforeshortening

?long axis of tibia aligned?long axis of tibia aligned ?tibiotalar joint in center of field with ?tibiotalar joint in center of field with

distal 4distal 4thth of tibia & fibula, talus and soft of tibia & fibula, talus and soft tissue on filmtissue on film

Ankle (Medial- internal Ankle (Medial- internal oblique)oblique)

ID requirements / marker / no preventable artifactsID requirements / marker / no preventable artifacts Contrast & density with good penetrationContrast & density with good penetration ?adequate obliquity: distal fibula seen without talar ?adequate obliquity: distal fibula seen without talar

superimposition, with an open lateral mortise, also superimposition, with an open lateral mortise, also lateral & medial malleoli in profilelateral & medial malleoli in profile

?tibiotalar joint open and tibia seen without ?tibiotalar joint open and tibia seen without foreshorteningforeshortening

?calcaneus seen distal to lateral mortise and fibula?calcaneus seen distal to lateral mortise and fibula ?long axis of tibia aligned?long axis of tibia aligned ?tibiotalar joint in center of field?tibiotalar joint in center of field

Ankle ( lateral)Ankle ( lateral)

?true lateral?true lateral ?domes of talus superimposed?domes of talus superimposed ?tibiotalar joint open with distal fibula ?tibiotalar joint open with distal fibula

superimposed by the posterior ½ of distal tibiasuperimposed by the posterior ½ of distal tibia ?long axis of foot at 90 degree angle with lower ?long axis of foot at 90 degree angle with lower

legleg ?long axis of tibia aligned ?long axis of tibia aligned ?tibiotalar joint at center of field showing talus, ?tibiotalar joint at center of field showing talus,

1 inch of 51 inch of 5thth metatarsal base, soft tissue and metatarsal base, soft tissue and distal ¼ of fibula and tibia on filmdistal ¼ of fibula and tibia on film

Knee (AP)Knee (AP)

?femorotibial joint open?femorotibial joint open ?anterior and posterior condylar margins of tibia ?anterior and posterior condylar margins of tibia

superimposedsuperimposed ?intercondylar eminence and tubercles are seen in ?intercondylar eminence and tubercles are seen in

profileprofile ?fibular head seen distal to tibial plateau?fibular head seen distal to tibial plateau ?patella lies superior to patellar surface of femur and is ?patella lies superior to patellar surface of femur and is

lateral to knee midlinelateral to knee midline ?intercondylar fossa partially seen?intercondylar fossa partially seen ?femorotibial joint is in center of field with ¼ of distal ?femorotibial joint is in center of field with ¼ of distal

femur & proximal lower leg with soft tissue on filmfemur & proximal lower leg with soft tissue on film

Knee (medial & lateral Knee (medial & lateral oblique)oblique)

ID requirements / marker / no preventable artifactsID requirements / marker / no preventable artifacts Contrast & density with good penetrationContrast & density with good penetration 60 to 70 kVp for knee thickness under 5 inches( don’t 60 to 70 kVp for knee thickness under 5 inches( don’t

need grid)need grid) Above 70 kVp for thicker knees for use of gridAbove 70 kVp for thicker knees for use of grid ?femorotibial joint open; anterior & posterior condylar ?femorotibial joint open; anterior & posterior condylar

margins of tibia are superimposed with fibular head margins of tibia are superimposed with fibular head distal to tibial plateaudistal to tibial plateau

?femorotibial joint in center of field with ¼ of distal ?femorotibial joint in center of field with ¼ of distal femur & proximal lower leg on filmfemur & proximal lower leg on film

Knee (medial oblique)Knee (medial oblique)

?rotated 45 degrees medially?rotated 45 degrees medially This places the lateral condyle in profile This places the lateral condyle in profile

and rotates the fibular head from beneath and rotates the fibular head from beneath tibiatibia

Too much-femoral condyles are almost Too much-femoral condyles are almost superimposedsuperimposed

Not enough-tibia slightly superimposes Not enough-tibia slightly superimposes the fibular headthe fibular head

Knee (lateral oblique)Knee (lateral oblique)

?rotated 45 degrees laterally?rotated 45 degrees laterally This places the medial condyle in profile and This places the medial condyle in profile and

rotates the tibia onto the fibularotates the tibia onto the fibula Not enough-fibular head is seen in center of Not enough-fibular head is seen in center of

tibiatibia Too much – fibular head is aligned with the Too much – fibular head is aligned with the

posterior edge of the tibia and the femoral posterior edge of the tibia and the femoral condyles are almost superimposedcondyles are almost superimposed

Knee (lateral)Knee (lateral)

ID requirements / marker / no preventable artifactsID requirements / marker / no preventable artifacts Contrast & density with good penetrationContrast & density with good penetration ?knee flexed 10 to 15 degrees with patella proximal to ?knee flexed 10 to 15 degrees with patella proximal to

patellar surface of the femur and patellofemoral joint patellar surface of the femur and patellofemoral joint openopen

?distal joint surfaces of medial & lateral femoral ?distal joint surfaces of medial & lateral femoral condyles superimposed with the femorotibial joint condyles superimposed with the femorotibial joint space openspace open

?anterior & posterior surfaces of the medial & lateral ?anterior & posterior surfaces of the medial & lateral femoral condyles superimposed with tibia slighlty femoral condyles superimposed with tibia slighlty superimposing fibular headsuperimposing fibular head

?femorotibial joint in centr of field?femorotibial joint in centr of field