Lower Extremity PP Flashcards
What is the angle of the Central Ray (CR) for the axial projection of the calcaneus?
40 degrees cephalic angle
The CR enters the plantar surface at the base of the third metatarsal.
What structures are shown in the axial projection of the calcaneus?
Axial projection of the calcaneus, talocalcaneal joint, and sustentaculum tali in profile
What is the patient position for the axial (plantodorsal) calcaneus projection?
Supine or seated position with the legs fully extended
What is the part position for the axial (plantodorsal) calcaneus projection?
Ankle in right-angle dorsiflexion
What are the essential projections for the calcaneus?
- Axial (plantodorsal)
- Axial (dorsoplantar)
- Lateral (mediolateral)
What is indicated by proper collimation and side marker in evaluation criteria?
Evidence of proper collimation and side marker
In the lateral calcaneus projection, what is the central ray (CR) position?
Perpendicular to calcaneus, centered 1 inch distal to medial malleolus at subtalar joint
What structures are shown in the lateral calcaneus projection?
Ankle joint and calcaneus in lateral profile
What is the evaluation criteria for the lateral calcaneus projection?
- Entire calcaneus
- Ankle joint and adjacent tarsals
- No rotation of calcaneus
- Tuberosity in profile
- Sinus tarsi open
- Calcaneocuboid and talonavicular joints open
What is the patient position for the AP ankle projection?
Supine or seated position with the affected extremity fully extended
What is the central ray (CR) for the AP ankle projection?
Perpendicular to a point just above the base of the 3rd metatarsal
What structures are shown in the lateral feet weight-bearing method?
Accurate evaluation and comparison of the tarsals and metatarsals
What is the evaluation criteria for the AP oblique foot projection?
- Evidence of proper collimation and side marker
- Anatomy from toes to tarsals
- No rotation of foot
- Open joint space between medial and intermediate cuneiforms
What is the difference between the medial and lateral oblique foot projections?
Medial oblique preferred for better visualization of lateral side joints of midfoot and hindfoot
What does the tibial tuberosity serve as?
Point of attachment for muscles
What is the classification of the fibula?
Classified as a long bone
What is a Jones Fracture?
An avulsion fracture of the base of the fifth metatarsal
What is the significant anatomical feature of the proximal tibia?
Intercondylar eminence
What is the position of the fibula compared to the tibia?
Located on the lateral side and slightly posterior
What are the structures shown in the AP oblique ankle projection?
Entire ankle mortise joint in profile
What is the central ray (CR) for the AP oblique mortise joint projection?
Perpendicular to ankle joint, entering midway between malleoli
What is the patient position for an AP Oblique Mortise Joint projection?
Supine or seated
The leg should be extended with the ankle centered to the image receptor.
What is the part position for an AP Oblique Mortise Joint projection?
Leg extended, ankle centered to IR, foot dorsiflexed to right angle, leg and foot rotated medially 15 to 20 degrees
The intermalleolar plane must be parallel with the IR.
Where does the Central Ray (CR) enter for the AP Oblique Mortise Joint projection?
Perpendicular to ankle joint, entering midway between malleoli
What structures are shown in an AP Oblique Mortise Joint projection?
Entire ankle mortise joint in profile, three sides of the mortise joint visualized
What are the evaluation criteria for an AP Oblique Mortise Joint projection?
Proper collimation and side marker, entire ankle mortise joint, distal tibia, fibula, and talus, proper 15 to 20 degree rotation of ankle, talofibular and tibiotalar articulations open, no overlap of anterior tubercle of tibia and superolateral portion of talus with fibula, bony trabecular detail and soft tissue
What is the central ray direction for an AP projection of the foot?
Perpendicular to base of third metatarsal
What is the central ray direction for an AP axial projection of the foot?
Angled 10 degrees toward heel entering base of the third metatarsal
What is the patient position for an AP or AP Axial Foot projection?
Supine or seated
The knee should be flexed, and the plantar surface of the foot should rest on the IR.
What is the significance of the axial projection in foot imaging?
Demonstrates the tarsometatarsal joint spaces better and reduces foreshortening
What are the essential projections for the foot?
- AP
- AP axial
- AP oblique
- Lateral (mediolateral)
- AP axial weight bearing
- Lateral weight bearing
What bones form the ankle joint?
- Lateral malleolus of fibula
- Inferior surface of tibia
- Medial malleolus of tibia
What type of joint is the ankle classified as?
Synovial, hinge-type joint; allows flexion and extension
What mnemonic can aid in recalling the names of the tarsal bones?
C = hubby, C = calcaneus, T = twisted, T = talus, N = never, N = navicular, C = could, C = cuboid, C = cha, C = cuneiform—medial, C = cha, C = cuneiform—intermediate, C = cha, C = cuneiform—lateral
What are the names of the cuneiform bones?
- Medial cuneiform
- Intermediate cuneiform
- Lateral cuneiform
What are sesamoid bones?
Two small detached bones found in the foot, usually form in points of stress near a joint
Which tarsal bone is the largest?
Calcaneus
What is the joint located in the great toe called?
Interphalangeal Joint
How many phalanges are in each foot?
14 phalanges
Two in the great toe and three in each of the other four toes.
What is the classification of the metatarsophalangeal (MTP) joints?
Ellipsoidal-type joints
What is the central ray direction for an AP Oblique Toes projection?
Perpendicular to third MTP joint
What are the evaluation criteria for the AP or AP Axial Toes projection?
Evidence of proper collimation, side marker visible and clear of anatomy of interest, entire toes, distal ends of the metatarsals, no rotation of phalanges, soft tissue width and midshaft concavity equal on both sides, open IP and MTP joint spaces
What is the patient position for a lateral toe projection?
Lateral recumbent
Prevent superimposition by taping the unaffected toes.
What is the central ray direction for a lateral toe projection?
Perpendicular to interphalangeal (IP) joint of great toe or proximal interphalangeal (PIP) joint of affected toe
What is the purpose of proper collimation in radiographic procedures?
To limit radiation exposure and improve image quality
How is the knee joint classified?
Synovial, modified-hinge joint
What ligaments support the knee joint?
- Posterior cruciate ligament (PCL)
- Anterior cruciate ligament (ACL)
- Tibial collateral ligament (TCL)
- Fibular collateral ligament (FCL)
What is the largest sesamoid bone in the body?
Patella
What is the evaluation criteria for proper femur imaging?
Evidence of proper collimation and side marker
* Most of the femur and joint nearest the pathologic condition
* Femoral neck not foreshortened on proximal femur
* Lesser trochanter not seen beyond the medial border of the femur
* No knee rotation on the distal femur
* Orthopedic appliance in its entirety
* Bony trabecular detail and soft tissue
These criteria ensure that the entire area of interest is captured clearly for diagnosis.
What structures are shown in a lateral projection of the femur?
Lateral projection of ¾ of the femur and adjacent joint
Two IRs may be used to demonstrate the entire length of the femur.
What should be evident in the evaluation criteria for a lateral femur projection?
Evidence of proper collimation and side marker
* Superimposed anterior surface of the femoral condyles
* Patella in profile
* Open patellofemoral space
* Inferior surface of the femoral condyles not superimposed
These details are crucial for assessing the knee joint and surrounding structures.
What is the central ray (CR) positioning for an AP femur projection?
Perpendicular to midfemur and the center of IR
This positioning ensures that the entire area of interest is captured accurately.
What is the recommended leg position for an AP femur projection?
Leg extended
* Affected thigh centered to midline of IR
* Top of IR at ASIS
* Extremity rotated internally 10 to 15 degrees
This positioning helps to visualize the femoral neck clearly.
What is the CR angle required for a tangential patella projection if the joint is not perpendicular to the IR?
Angle depends on the amount of knee flexion
* Typical angle: 15 to 20 degrees cephalad
Adjusting the angle is necessary to obtain a clear image of the patellofemoral joint.
What is the patient position for a tangential patella (Settegast) projection?
Supine or prone can be used
* Slowly flex knee as much as possible
* Adjust leg to place long axis vertical
This positioning ensures the patella is perpendicular to the IR.
What structures are shown in a lateral projection of the patella?
Lateral projection of patella and patellofemoral joint space
This view helps assess any potential fractures or joint issues.
What is the evaluation criteria for a lateral patella projection?
Evidence of proper collimation and side marker
* Patella in profile
* Femoral condyles and intercondylar sulcus
* Open patellofemoral articulation
* Bony trabecular detail and soft tissue
Ensuring these elements are visible is critical for accurate assessment.
What is the recommended patient position for an AP leg projection?
Supine
* Femoral condyles parallel with IR
* Ankle flexed to place foot vertical
* IR must extend 1 to 1.5 inches beyond the joints
Proper positioning is necessary to visualize the tibia and fibula without rotation.
What is the essential projection for the knee?
AP
* Lateral (mediolateral)
* AP oblique (lateral rotation)
* AP oblique (medial rotation)
These projections help assess the knee joint from different angles.
What should be included in the evaluation criteria for knee imaging?
Evidence of proper collimation and side marker
* Patella completely superimposed by femur
* No rotation
* Bony trabecular detail and soft tissue
These criteria ensure clarity and accuracy in the knee joint imaging.
What is the proper positioning for a lateral leg projection?
Lateral surface of leg resting on IR
* Patella perpendicular to IR
* Femoral condyles superimposed and perpendicular to IR
* Include both joints on IR
This positioning is important for obtaining a true lateral image.
What is the method for performing a cross-table lateral leg projection?
Use if patient cannot be turned from the supine position
* IR placed between legs
* CR directed from lateral side
This method allows for imaging without requiring patient movement.
What is the definition of ‘SID’ in radiographic procedures?
Source-to-image distance
Typically standardized at 40 inches to ensure consistent imaging results.
What are the essential projections for the patella?
Tangential (Settegast)
* PA
* Lateral
* PA axial (intercondylar fossa)
These projections are utilized to assess the patellofemoral joint and surrounding structures.
What is the purpose of gonad shielding in radiography?
To be used according to state regulations or to reduce patient anxiety
Gonad shielding helps protect reproductive organs from radiation exposure.
What are the key components of optimum technique factors in radiation protection?
Patient preparation, general patient position, IR/collimation size, SID, ID markers, radiation protection, patient instructions
These factors are crucial for ensuring effective and safe radiographic procedures.
What is SID in radiography?
Standardized as a part of procedural protocol, typically 40” SID
SID stands for Source-to-Image Distance, which impacts image quality and radiation dose.
What structures are included in the distal femur anatomy?
Medial condyle, lateral condyle, patellar surface, intercondylar fossa, epicondyles
The distal femur is critical for knee joint function.
What is the function of the greater trochanter in the proximal femur?
It is a large prominent, palpable process at the proximal end on the lateral side
The greater trochanter serves as a site for muscle attachment.
What does the head of the femur articulate with?
Acetabulum of pelvis to form hip joint
This articulation is essential for hip joint mobility.
How is the femur classified?
As a long bone
The femur is the largest, strongest, and heaviest bone in the body.
What are the components of the femur?
Body, two articular extremities
The body is cylindric and convex anteriorly, slanting medially 5-15 degrees.
What is the importance of patient preparation in radiography?
To remove artifacts from the anatomy of interest
Artifacts can interfere with the diagnostic quality of images.
What is the recommended positioning for ambulatory patients during radiography?
Seated on x-ray table with affected extremity resting on the IR placed on the tabletop
This positioning ensures comfort and effective imaging.
What should be done for non-ambulatory patients during radiography?
Alter positioning to maximize patient comfort, using grid IR for larger parts
Patient comfort is crucial for obtaining quality images.
What is the guideline for IR/collimation size in radiography?
Use the smallest IR that will demonstrate all of the anatomy of interest
This minimizes radiation exposure and improves image quality.
What is the central ray (CR) entry point for the AP Knee?
½ inch (1.3 cm) below patellar apex
The CR angle varies based on ASIS-to-tabletop measurement.
What is the patient position for the AP Knee?
Supine with no rotation of pelvis, knee fully extended if possible
Proper positioning is essential for accurate imaging.
What structures are shown in the PA Axial (Holmblad) view?
Intercondylar fossa, posteroinferior articular surfaces of the femur, tibial plateaus
This view provides detailed visualization of knee structures.
What are the evaluation criteria for the AP Knee?
Evidence of proper collimation and side marker, knee fully extended, symmetric femoral condyles
These criteria ensure the quality and diagnostic value of the image.
What is the angle for the central ray in the PA Axial (Camp-Coventry) view?
40 degrees caudad when knee flexed 40 degrees, 50 degrees caudad when knee flexed 50 degrees
The angle varies based on the degree of knee flexion.
What are the essential projections for the patella?
PA, lateral (mediolateral), tangential (Settegast method), tangential (Merchant)
These projections help in evaluating patellar pathology.
What is the evaluation criteria for the AP Oblique Knee?
Fibular head and tibia slightly superimposed, open patellofemoral joint space, bony trabecular detail
This ensures that the knee joint is adequately visualized.
What is the central ray entry point for the lateral knee view?
1 inch (2.5 cm) distal to medial epicondyle
This entry point is critical for accurate lateral imaging.
