Lower extremity

Intended Learning Outcomes The student should be able to recognize clinical radiographic technical principles of the lower limb.

A-P Lower Leg Measure: A-P at mid-lower leg Protection: Apron draped over pelvis SID: 40” Table top No Tube Angle Film: 7”x17 I.D. down or diagonal 14” x 17

A-P Lower Leg Patient lies on back on table. Leg internally rotated 15° until in true A-P position Film centered to include knee and ankle joints. The top of the film will be about 2” above knee. Horizontal CR is centered to film

A-P Lower Leg Vertical CR: long axis of lower leg Collimation top to bottom: From knee joint to ankle joint or slightly less than film size. Collimation side to side: soft tissue of lower leg Instructions: Remain still Make exposure and let patient relax.

A-P Lower Leg Film Must include both knee and ankle articulations No evidence of rotation As with this example, the 14” x 17” cassette can be turned diagonally to get both joint spaces on film.

Lower Leg Lateral Measure: Lateral at mid lower leg Protection: Apron draped over pelvis SID: 40” Table Top No Tube Angle Film: 7” x 17” I.D. down or diagonal 14”x17” Regular

Lower Leg Lateral Patient lies on affected side with lower leg in lateral position. Film centered under leg to get both knee joint and ankle joint on film. Top of film will be about 2” above knee joint. Horizontal CR centered to film

Lower Leg Lateral Vertical CR: long axis of lower leg. Collimation top to bottom: to include knee joint space and ankle joints Collimation Side to side: soft tissues of lower leg.

Lower Leg Lateral Make sure that the knee and ankle are in lateral position. The condyles should be perpendicular to film and foot in lateral position. Collimation Top to Bottom: include both knee joint space and ankle joints

Lower Leg Lateral Collimation Side to Side: soft tissues of lower leg. Instructions: Remain still Make exposure and let patient relax

Lower Leg Lateral Film Must include both knee and ankle joints. Both joints should be in true lateral positions. A 14” x 17” may be turned diagonally to get both joints on film.

Ankle Radiography Routine views at PCCW Mortise Oblique Medial Oblique Lateral We do both oblique views for Dr. Scuderi The mortise open the joints better The medial oblique demonstrates Jones Fractures.

A-P Ankle

Ankle A-P Measure: A-P at malleoli Protection: lead apron SID: 40” Table Top No Tube Angle Film: 1/2 of 12” x 10 extremity cassette I.D. up

Ankle A-P Patient is seated or lying on table. Leg is internally rotated until the leg is in a true A-P position position. The foot is dorsiflexed until the plantar surface is perpendicular to film. Horizontal CR: at level of talo-tibial joint or malleoli.

Ankle A-P Half of film is centered to Horizontal CR. Vertical CR: Long axis of lower leg. Collimation top to bottom: distal lower leg to soft tissue below calcaneus. Slightly less than film size.

Ankle A-P Collimation side to side: soft tissue of lower leg and ankle. Patient Instructions: Remain still Make exposure and let patient relax.

Ankle A-P Film A-P on left. There should be no rotation as evidenced by the medial mortise joint being open. The talotibial joint should also be open. Soft tissue of plantar area of foot should be seen.

Ankle Oblique Views Mortise Medial

Always take a medial oblique Medial Oblique Lateral Oblique

Ankle Medial Oblique Measure: A-P at malleoli Protection: lead apron SID: 40” Table Top No Tube Angle Film: 1/2 of 12” x 10 extremity cassette I.D. up

Ankle Medial Oblique Patient is seated or lying on table. Leg is internally rotated 45° from true A-P position position. The foot is dorsiflexed until the plantar surface is perpendicular to film. Horizontal CR: at level of talo-tibial joint or malleoli.

Ankle Medial Oblique Half of film is centered to Horizontal CR. Vertical CR: Long axis of lower leg. Collimation top to bottom: distal lower leg to soft tissue below calcaneus. Slightly less than film size.

Ankle Medial Oblique Collimation side to side: soft tissue of lower leg and ankle. Patient Instructions: Remain still Make exposure and let patient relax.

Ankle Medial Oblique Film Oblique on right. The lateral malleolus should be clear of the talus. The medial mortise joint may be open The talotibial joint should also be open. The tarsal sinus will be open.

Ankle Mortise Oblique Measure: A-P at malleoli Protection: lead apron SID: 40” Table Top No Tube Angle Film: 1/2 of 12” x 10 extremity cassette I.D. up

Ankle Mortise Oblique Patient is seated or lying on table. Leg is internally rotated until the medial and lateral malleoli are parallel to the film , about 15 to 20 °. The foot is dorsiflexed until the plantar surface is perpendicular to film. Horizontal CR: at level of talotibial joint or malleoli.

Ankle Mortise Oblique Half of film is centered to Horizontal CR. Vertical CR: Long axis of lower leg. Collimation top to bottom: distal lower leg to soft tissue below calcaneus. Slightly less than film size.

Ankle Mortise Oblique Collimation side to side: soft tissue of lower leg and ankle. Patient Instructions: Remain still Make exposure and let patient relax.

Ankle Mortise & Oblique Film Oblique on right., Mortise on left The lateral malleolus should be clear of the talus. The medial mortise joint must be open The talotibial joint should also be open.

Lateral Ankle

Ankle Lateral Measure: Lateral at malleoli Protection: Lead Apron SID: 40” Table Top No Tube Angle Film: 8” x 10” I.D. up

Ankle Lateral Patient lies on the affected side with lower leg aligned with table center line. Foot dorsa-flexed to form a 90° angle with lower leg. Plantar surface of foot is perpendicular to film and malleoli are perpendicular to film.

Ankle Lateral Horizontal CR: medial malleolus Vertical CR: medial malleolus and long axis of lower leg. Collimation top to bottom: distal tibia to soft tissue below calcaneus

Ankle Lateral Collimation side to side: to include soft tissue around calcaneus and lower leg. Instructions: Remain still Make exposure and let patient relax.

Ankle Lateral Film Must include distal tibia, talus and calcaneus. The talus domes must be superimposed. The fibula should overlie the distal tibia. The talotibial joint should be open. Note wrong I.D. location

Calcaneus Axial View Measure: Lateral at calcaneus Protection: Lead Apron SID: 40” Table Top Tube Angle: 40° cephalad Film: 1/2 of 8”x10” Extremity Cassette

Calcaneus Axial View Patient lies or sits on table with affected leg centered to table. Lower leg in true A-P position and foot dorsiflexed until the plantar surface is perpendicular to film. A strap or tape may be used for the patient to hold foot in dorsiflexion.

Calcaneus Axial View Horizontal CR: 1.5 to 2” up the calcaneus tuberosity Film centered to Horizontal CR. Vertical CR: long axis of foot. Collimation top to bottom: to include all of calcaneus and adjacent soft tissues

Calcaneus Axial View Collimation Side to Side: soft tissue of foot or slightly less than 1/2 of film. Instructions: Remain still Make exposure and let patient relax.

Calcaneus Axial View Film The calcaneus tuberosity will be seen free of distortion. The Calcaneal-Talus joint space should be seen. If the foot is not properly dorsiflexed, the joint space will be closed and the tuberosity foreshortened.

Calcaneus Lateral View Measure: Lateral at calcaneus Protection: Lead Apron SID: 40” Table Top No Tube Angle Film: 1/2 of 8”x10” Extremity Cassette

Calcaneus Lateral View Patient lies on table on affected side with affected leg centered to table. Lower leg in true lateral position and foot dorsiflexed. Horizontal CR: 1.5 to 2” up the calcaneus tuberosity Film centered to Horizontal CR.

Calcaneus Lateral View Vertical CR: through medial malleoli Collimation top to bottom: to include all of calcaneus and adjacent soft tissues Collimation Side to Side: soft tissue of foot or slightly less than 1/2 of film.

Calcaneus Lateral View Instructions: Remain still Make exposure and let patient relax.

Calcaneus Lateral Film The calcaneus, talus and ankle should be demonstrated in a true lateral position. The domes of the talus will be superimposed. Soft tissues adjacent to the calcaneus and ankle should be visualized.

Foot Radiography Fractures are characterized by involvement of the subtalar joint (75%) and not involving the subtalar joint. Stress fractures are common in runners but typically not seen on radiographs. Stress fractures , plantar fascitis or heel spurs are common repetitive use conditions.

Foot or Heel Radiography Views of the foot and calcaneus are totally different. If a heel injury is suspected, take heel views and not foot views. A 30 degree medial oblique view can be useful. The oblique and lateral will demonstrate the subtalar joint.

Foot Radiography Foot view must include the tarsal bones, metatarsals and phalanges. A tube angle is used to open the tarsal bone articulations on the A-P view. If the patient is flat footed, no tube angle would be needed.

Foot Radiography The medial oblique view is particularly useful. It provides: A clear view of the tarsal bone including the calcaneus. The 4th & 5th metatarsals Intertarsal joints Detail of the 5th metatarsal

Foot Radiography The “basketball foot” is a traumatic medial subtalar dislocation resulting from landing on an inverted foot. The “Jones fracture is an avulsion fracture off the base of the 5th metatarsal. Stress fractures of the metatarsals are generally transverse resulting from marching or jumping.

Toe Radiography Toe radiography can be particularly challenging. The natural curve of the toes toward the plantar surface of the foot results in foreshortening and closure of the interphalangeal joint spaces. Besides the A-P, an angled axial view is used to open the joint spaces.

Foot A-P Measure: A-P at base of third metatarsal Protection: Apron SID: 40” Table Top Tube Angle: 10° cephalad Film: 1/2 of 10” x 12 Extremity Cassette I.D. up

Foot A-P Patient seated or lying on table with the long axis of the affected foot centered to table. Place cassette on table. Have patient place foot flat on cassette. Horizontal CR: base of third metatarsal

Foot A-P Vertical CR: long axis of foot. Collimation Top to Bottom: distal tibia to tips of toes. Collimation Side to Side: soft tissue of foot Instructions: Remain still Make exposure and let patient relax

Foot A-P Film Should demonstrate toes , metatarsals and most of the tarsal bones. The talus and calcaneus will not be seen. The tube angle will help open the tarsal joint spaces.

Foot Oblique Measure: A-P at base of third metatarsal Protection: Apron SID: 40” Table Top No Tube Angle Film: 1/2 of 10” x 12 Extremity Cassette I.D. up

Foot Oblique Patient seated or lying on table with the long axis of the affected foot centered to table. Place cassette on table. Have patient place foot flat on cassette. The foot is medially rotated 30 to 40° A sponge may be used under the plantar surface of the foot.

Foot Oblique Horizontal CR: base of third metatarsal Vertical CR: long axis of foot. Collimation Top to Bottom: distal tibia to tips of toes. Collimation Side to Side: soft tissue of foot Instructions: Remain still Make exposure and let patient relax

Foot Oblique Film Should demonstrate toes , metatarsals and most of the tarsal bones. The talus and calcaneus will not be seen. The calcaneus will be well visualized Tarsal joint spaces should be open.

Foot Lateral Measure: Lateral at base of first metatarsal Protection: Lead Apron SID: 40” Table Top No Tube Angle Film: 8” x 10” or 10” x 12” Extremity depending on foot size.

Foot Lateral Patient lies on the affected side with lower leg in lateral position. The foot should be dorsiflexed until the plantar surface is perpendicular to ankle. The plantar surface of foot is perpendicular to film.

Foot Lateral The film may be turned diagonally or the foot placed diagonally on film to fit the entire foot on the film. Horizontal CR: base of 1st metatarsal Vertical CR: base of first metatarsal

Foot Lateral Collimation Top to Bottom: to include ankle to plantar surface soft tissue Collimation Side to Side: to include from heel to tips of toes. Instructions: Remain still Make exposure and let patient relax.

Foot Lateral Film The foot and ankle should be in a lateral position. The metatarsals and toes will be superimposed. The distal fibula should overlie the distal tibia. The talotibial joint space should be open.

Toes A-P & Axial A-P Measure: A-P at 3rd metatarsal phalangeal joint or affected toe Protection: Lead Apron SID: 40” Table Top Tube Angle A-P: none Tube Angle Axial A-P: 15° cephalad Film: 1/4 of 10 x 12 Extremity

Toes A-P & Axial A-P A-P : patient places foot flat on film. Horizontal & Vertical CR: 3rd M-P joint for all toes or M-P joint of the affected toe for individual toe series. A-P Axial tube angle: same as above but with 15° cephalad angle.

Toes A-P & Axial A-P A-P Axial with Sponge: a 15° sponge is placed under toes instead of angling the tube. Or The Sponge is placed under the cassette Horizontal & Vertical CR: 3rd M-P joint for all toes or M-P joint of affected toe.

Toes A-P & Axial A-P Collimation top to bottom: to include all M-P joints to tips of toes or M-P joint to tip of affected toe. Collimation Side to Side: soft tissue of foot or individual toe. Instructions: Remain Still Expose and let patient relax

Toes A-P & Axial A-P Film A-P is upper right image. A-P Axial is upper left image. The phalangeal joints will be open on the axial view. Views must include all of the affected toe or toes. Note that collimation was too tight top to bottom.

Toes Medial Oblique Measure: A-P at metatarsal-phalangeal joints Protection: Apron SID: 40” Table Top No tube angle Film: 1/4 of 10” x 12” or 8” x 10” Extremity Cassette

Toes Medial Oblique Patient places distal foot on unexposed portion of cassette. Patient medially rotates lower leg until the plantar surface forms a 30 to 45° angle. Horizontal CR: 3rd MTP joint or the affected toe.

Toes Medial Oblique Vertical CR: centered to long axis of foot or the affected toe Collimation top to bottom: Distal metatarsal to tips of toes or affected toe Collimation side to side: soft tissue of foot or affected toe.

Toes Medial Oblique Patient instructions: Remain Still Make exposure and let patient relax. Note that a sponge may be placed under plantar surface of foot to control angle of view . It will also make it more comfortable for the patient.

Toes Medial Oblique The joint spaces should be open. The distal metatarsal and tips of the toes should be visualized.

Toes Lateral Measure: Lateral across the metatarsal-phalangeal joints For individual toe use A-P measurement. Protection: Apron SID: 40” Table Top No tube angle Film: 1/4 of 10” x 12” or 8” x 10” Extremity Cassette

1st Toe Lateral Patient places distal foot on unexposed portion of cassette. For 1st through 3rd toes Patient medially rotates lower leg until the plantar surface forms a 90° angle. For 4th and 5th toes Patient laterally rotates foot until the plantar surface is perpendicular to film.

2nd Toe Lateral For individual toes, tape and tongue depressors are used to clear the other toes out of the view. Without the use of tape and tongue depressors, there will be too much superimposition

3rd Toe Lateral Horizontal CR: 3rd MTP joint or the affected toe. Vertical CR: centered to long axis of foot or the affected toe Collimation top to bottom: Distal metatarsal to tips of toes or affected toe Collimation side to side: soft tissue of foot or affected toe.

4th Toe Lateral Patient instructions: Remain Still Make exposure and let patient relax. Note that the lateral surface of the foot is next to the film.

5th Toe Lateral Note that the lateral surface of the foot is next to the film. The toe need to remain parallel to the film. The 5th toe is the most challenging lateral toe view.

Toes Lateral Film The joint spaces should be open. The distal metatarsal and tips of the toes should be visualized. The affected toe should be free of superimposition.

ASSIGNMENT One student will be selected for assignment

Question Mention routine radiographic positioning of the ankle joint

Suggested Readings Clark’s radiographic positioning and techniques

Return to Lecture Index Return to Radiologic Technology Two Home Page End of Lecture Return to Lecture Index Return to Radiologic Technology Two Home Page