Pelvis, Hip, and SI Joints

Question 1

AP Pelvis

Positioning and Image Eval

Answer 1

-Pt supine with legs extended and internally rotated 15-20 degrees
-IR centered 2” inferior to ASIS and 2” superior to pubic symphysis
-upper border of IR 1-2” above crest
Image Eval
-proper rotation of legs: greater trochanter in profile
-no rotation of pelvis: both ilia symmetrical and saccrum and coccyx in line with symphysis

Question 2

AP Hip

Positioning and Image Eval

Answer 2

-Pt supine with affected leg internally rotated 15-20 degrees
-Center IR ~2.5” distal to a line drawn between the symphysis and ASIS
Image Eval
-Greater trochanter and femoral neck in profile
-inferior ilium and ischium on image

Question 3

AP Oblique Bilateral Hips
(Modified Cleaves or “Frog Leg”)
Positioning and Image Eval

Answer 3

-Pt supine with knees and thighs flexed, and laterally adducted to about 45 degrees
-center IR to 1” superior to pubic symphysis
Eval
-no rotation of pelvis
-lesser trochanter on medial side of femur
-femoral neck without superimposition of greater trochanter

Question 4

AP Oblique Unilateral Hip
(Modified Cleaves or (Frog Leg”)
Positioning and Image Eval

Answer 4

-Pt roll slightly to affected side, flex knee, and draw up knee to about 45 degrees
-center IR at the ASIS
Eval
-some rotation of pelvis
-entire hip joint and proximal femora
-femoral neck without greater trochanter superimposition

Question 5

AP Axial Pelvis (Outlet Anterior Pelvis bones)

Positioning and Image Eval

Answer 5

-Pt supine
-CR entering at 2” inferior to superior symphysis
-CR angled cephalad 20-35 degrees for males or 30-45 degrees for females
Eval
-pubic bones magnified and superimposed by coccyx and saccrum
-no rotation seen by symmetric obturator foramina

Question 6

Superoinferior Axial Pelvis (Inlet Projection)

Positioning and Image Eval

Answer 6

-Pt supine
-IR centered with the greater trochanters
-CR entering 40 degrees caudad at level of ASIS
Eval
-medially superimposed superior and inferior rami of pubic bones
-symmetrical pubic bones and ischial spines

Question 7

AP Oblique Acetabulum (Judet Method)
Internal Rotation
Positioning and Image Eval

Answer 7

-Pt rolled unaffected side UP to 45 degrees
-IR centered to affected hip
-perpendicular CR
Eval
***must show iliopubic column and posterior rim of acetabulum

Question 8

AP Oblique Acetabulum (Judet Method)
External Rotation
Positioning and Image Eval

Answer 8

-Pt rolled affected side DOWN to 45 degrees
-IR centered to affected hip
-perpendicular CR
Eval
***must show ilioischial column and anterior rim of acetabulum

Question 9

Cross Table Lateral Hip
Danelius-Miller Method
Positioning and Image Eval

Answer 9

-Pt supine with unaffected leg elevated out of FOV
-IR placed behind affected leg and parallel to femoral neck
-CR perp. entering femoral neck SID 72” when poss.
Eval
-entire hip joint with acetabulum
-femoral neck without superimposition of greater trochanter
-ischial tuberosity projected below femoral neck

Question 10

AP Axial SI Joints

Positioning and Image Eval

Answer 10

-Pt supine with no rotation
-CR angled 30 (male) or 35 (female) degrees cephalad; enters 2” inferior to ASIS
Eval
-Open intervertebral disk space (L5-S1)
-both SI joints demonstrated

Question 11

AP Oblique SI Joints (LPO, RPO)

Positioning and Image Eval

Answer 11

-Pt rolled 25-30 degrees; affected side UP
-the side being examined is farthest from IR
-center IR at level of ASIS; perp. CR 1” medial to elevated ASIS
Eval
-open SI joint space
-minimal overlapping of ilium and sacrum

Question 12

PA Oblique SI Joints (LAO, RAO)

Positioning and Image Eval

Answer 12

-Pt rolled 25-30 degrees; affected side DOWN
-the side closest to IR is being examined
-center IR at level of ASIS; perp. CR 1” medial to the side-down ASIS
Eval
-open SI joint space
-minimal overlap of ilium and sacrum