2b. Pelvis

Question 1

what is the SID for pelvis views

Answer 1

110cm

Question 2

what is the kV for pelvis views

Answer 2

70-85kV

Question 3

what is the mAs for pelvis views

Answer 3

20mAs

Question 4

do you use a grid for pelvis views

Answer 4

yes

Question 5

what is patient positioning for the AP pelvis

in terms of body position and rotation

Answer 5

supine

lower limb and feet internally rotated

Question 6

what shows no pelvic rotation for AP pelvis views

Answer 6

ASIS equidistant to tabletop

Question 7

what is the CP for AP pelvis

Answer 7

perpendicular to midway between femoral heads

5cm inferior to ASIS and 2cm superior to the symphysis pubis

Question 8

what are the image critiques for AP pelvis in terms of positioning

what shows there is no rotation of the pelvis and what shows internal rotation of the feet and lower limbs

Answer 8

no rotation = obturator foramen and iliac wings symmetrical

internal rotation = lesser trochanter not visible, greater trochanter in profile

Question 9

what are the image critiques for AP pelvis in terms of area of interest

from where to where for collimation

4 things

Answer 9

iliac crest to proximal femur

pelvic girdle, L5, sacrum and coccyx

entire hip replacement if present

Question 10

what shows good exposure for AP pelvis

Answer 10

visualise L5 and sacrum and femoral head and acetabula margins through overlying pelvic structures without overexposing ischium and pubic bones

Question 11

what is the CP for an AP hip view

Answer 11

perpendicular to the 2.5-5cm distal to mid-femoral neck

6cm distal to midpoint of line joining the symphysis and ASIS

Question 12

what is the patient positioning for AP hip

in terms of lower limb rotation, pelvis and CR centering

Answer 12

feet/leg internally rotated 15-20*

no pelvis rotation

center femoral neck to CR

Question 13

what are the image critiques for AP pelvis in terms of area of interest

6 things

Answer 13

proximal 1/3 femur and adjacent pelvic girdle

femoral head and neck in profile

hip joint space and acetabulum

Question 14

if a hip replacement is present how much needs to be included in the image

Answer 14

all of it

Question 15

what are the image critiques for AP pelvis in terms of positioning

what shows internal rotation

Answer 15

internal rotation = lesser trochanter not visible

greater trochanter in profile

Question 16

what is the CP for an rolled lateral hip view

Answer 16

perpendicular to the mid-femoral neck

midpoint between ASIS and symphysis then go down ~5cm

Question 17

what is the patient positioning for rolled lateral hip

in terms of patient body rotation, affected knee and unaffected knee and femur alignment

Answer 17

patient rolled 45* to affected side

affected knee flex to 45*

femur at midline of table

unaffected knee behind affected

Question 18

what are the image critiques for rolled lateral pelvis in terms of area of interest

4 things

Answer 18

proximal 1/2-2/3 femur

femoral heads and necks

acetabulum

Question 19

what are the image critiques for rolled lateral pelvis in terms of positioning

what shows true lateral

Answer 19

true lateral = Greater and lesser trochanters superimposed on femur

Question 20

what is the CP for an horizontal ray lateral hip view

Answer 20

horizontal and perpendicular to the femoral neck

Question 21

what is the patient positioning for horizontal ray lateral hip

in terms of the patient position, pelvis, unaffected and affected leg position, rotation of leg and IR placement

Answer 21

supine

no pelvic rotation

unaffected leg/hip raised and flexed

internally rotate leg 15*

IR in crease above iliac crest and parallel to the femoral neck

Question 22

what are the image critiques for horizontal ray lateral pelvis in terms of area of interest

4 things

Answer 22

entire femoral head, neck, trochanters and acetabulum

Question 23

what are the image critiques for horizontal ray lateral pelvis in terms of positioning

Answer 23

opposite hip isn’t superimposed over affected hip and anatomy

no visible gridlines

minimal femoral neck distortion