imaging LE - exam 3

Question 1

what does a hip AP view visualize?

Answer 1

hip joint and proximal femur

Question 2

what is the iliofemoral line that you can see in a AP view

Answer 2

smooth curve along outer ilium that extends into the neck

Question 3

what is Shenton’s hip line that you can see in a AP view

Answer 3

smooth curve around obturator foramen

Question 4

what is the femoral neck angle seen in AP view

Answer 4

aka angle of inclination
angle between femoral shaft and neck

Question 5

what is observed as normal in hip AP view?

Answer 5

well preserved joint space
smooth margins of acetabulum and femoral head
obvious ball and socket
cortex margins on shaft
cancellous markings on head and neck

Question 6

what does a hip lateral frog leg view visualize?

Answer 6

head, neck and proximal femur

Question 7

what is observed as normal in hip lateral frog leg view?

Answer 7

lesser trochanter is more anterior
well preserved joint space
smooth margins of acetabulum and femoral head
obvious ball and socket

Question 8

what are routine radiographs of the hip?

Answer 8

AP
lateral frog leg

Question 9

what are routine radiographs of the knee?

Answer 9

AP
lateral
PA axial “tunnel” view
tangential view

Question 10

what does the knee AP view visualize?

Answer 10

distal femur
proximal tibia and respective joint
fibular head

Question 11

what are important observations of normal knee in AP view

Answer 11

patella superimposed and not typically visible unless patella baja
well defined joint spaces and equal
alignment of femur and tibia
distinct cortical margins and cancellous markings

Question 12

what does the knee lateral view visualize

Answer 12

profile of PF joint

Question 13

what are important observations in knee lateral view?

Answer 13

patellar alta/baja positioning

Question 14

what does the knee PA axial tunnel view visualize?

Answer 14

intercondylar fossa and eminence
post. femur and tibia
tibial plateaus
used to detect loose bodies, osteochondral defects, or narrowing of tibiofemoral joint space
often performed in standing for ARJC

Question 15

what is normal observation for knee AP axial tunnel view?

Answer 15

tunnel should be open, round and not squared off
well defined joint spaces and equal

Question 16

what does the knee tangential view visualize?

Answer 16

PF joint space and surfaces

Question 17

what is normal observation for knee tangential view?
- sulcus angle
- congruence angle

Answer 17

smooth and distinct surfaces
- sulcus angle, esp depth. if shallow, more prone to dislocations
- congruence angle - helps to define patellar position within the sulcus

Question 18

congruence angle:
____ deg is associated with patellar hypermobility and dislocations as there is greater medial tilt

Answer 18

> 16 deg

Question 19

conventional radiographs should be ordered after trauma to the knee for patients with:

Answer 19

age > 55
tenderness at fibular head
isolated tenderness of patella
inability to flx knee to 90
inability to walk four WB steps immediately after injury and in the ED

** can’t be used after 7 days of trauma

Question 20

what are the routine radiographs for the ankle?

Answer 20

AP
AP oblique (mortise)
lateral

Question 21

what does the ankle AP view visualize?

Answer 21

distal tibia and fibula and talar dome

Question 22

what is normal observation of an ankle AP view?

Answer 22

lateral malleolus more distal than medial
visualize upper and medial talus - medial or lateral shift of talus is abnormal
distal tibiofibular joint space - abnormally wide joint is abnormal

Question 23

what does an ankle AP oblique (mortise view) visualize?

Answer 23

entire ankle mortise with 15-20 deg of hip IR

Question 24

what is a normal observation of ankle AP oblique view?

Answer 24

entire talocrural joint space
mortise width - 3-4 mm or < 1/2 cm all the way around (normal)
distal tibiofibular joint - NO optimal radiographic parameter exists to assess syndesmotic integrity but > 6 mm is utilized

Question 25

what does the ankle lateral view visualize?

Answer 25

tibiotalar and subtalar joints
talonavicular and calcaneocuboid joints
bony members

Question 26

what is the ankle anterior drawer stress view? where do you measure from?

Answer 26

x-ray while performing ligamentous special test
measure from post. tibia to post. talus

Question 27

values of ankle anterior drawer stress view:
- normal:
- abnormal:
- _____ separation requires comparison between sides

Answer 27

• 5 mm or .5 cm
• > 10 mm or 1 cm
• 5-10 mm

Question 28

what is the ankle EV/IV stress view? where do you measure from?

Answer 28

x ray while performing ligamentous special test
measure angle between bottom of tibia and talar dome

Question 29

what are abnormal findings of the ankle EV/IV stress view?

Answer 29

mortise widens
talar displacement or tilt
> 15 deg for IV and > 10 deg for EV
if > 5 deg difference between sides of the body

Question 30

what are routine radiographs of the foot?

Answer 30

AP
lateral
oblique

Question 31

foot AP view visualizes:

Answer 31

mid and forefoot

Question 32

what are important normal observations of the foot AP view?

Answer 32

note individual mid and forefoot bones along with sesamoid bones
1st intermetatarsal angle - intersection of lines bisecting 1st and 2nd MT shafts
(normal < 5-10 deg)

Question 33

what does the foot lateral view visualize? how is that different from the ankle?

Answer 33

subtalar, talonavicular, and calcaneocuboid joints and members
different from ankle bc less tibiofibular imaged

Question 34

how do you take a radiograph in the foot oblique view?

Answer 34

foot and leg medially rotated

Question 35

what does the foot oblique view visualize?

Answer 35

primarily for forefoot
all tarsals except 1st cuneiform and portion of talus

Question 36

what are normal observations of the foot oblique view?

Answer 36

MTs image with sharp clearly defined cortical borders
sesamoids
2nd-4th distal phalanges difficult to visualize
note joint spaces of intermetatarsal and midtarsal joints

Question 37

radiographs should be ordered after trauma to the ankle with any of the following characteristics:

Answer 37

pain about the medial or lateral malleolus AND
- tenderness at post. aspect or tip of lateral malleolus OR
- tenderness at post. aspect or tip of medial malleolus OR
- inability to bear weight both immediately and in ED

Question 38

radiographs should be ordered after trauma to the foot with any of the following characteristics:

Answer 38

pain about the midfoot AND
- tenderness at 5th metatarsal base OR
- tenderness at navicular bone OR
- inability to bear weight both immediately and in ED

Question 39

how do ultrasound waves construct an image

Answer 39

US waves are absorbed, reflected and diffused differently from varying tissues

Question 40

two major advantages of ultrasound

Answer 40

offers real time information for superficial soft tissue
higher resolution for superficial tendon, ligament and muscle than MRI

Question 41

two major disadvantages of ultrasound

Answer 41

inability to scan deeper joint structures
image quality highly dependent on operator

Question 42

what is hyperechoic appearance

Answer 42

higher (brighter) signal from reflection of smoother and denser structures indicate swelling, tendinosis

Question 43

sonograph:
- tears:
- swelling, thickening

Answer 43

irregular borders or lack of structure
wider structure

Question 44

why choose radiographs for LE imaging?

Answer 44

initial images

Question 45

CT and MRI are recommended for :

Answer 45

complex fractures
osteochondral lesions

Question 46

MRI recommended for:

Answer 46

stress fxs and tendon abnormalities

Question 47

MRI arthrography with contrast recommended for:

Answer 47

ligamentous and cartilage issues

Question 48

ultrasound appropriate for:

Answer 48

superficial soft tissue abnormalities