Positioning of the Pelvis, Anterior Pelvic Bones, and SI Joints (RADS 320)

SID for Pelvis, Anterior Pelvic Bones, and SI Joints

40 inches

IR Size for Pelvis and Anterior Pelvic Bones

14x17 CW

How much do we invert the feet for and AP Pelvis?

15-20 degrees

Why do we invert the feet for AP Pelvis?

to overcome foreshortening or anteversion of the femoral necks placing then parallel to the IR

AP Projection of Pelvis: CR

perpendicular to midpoint 2 in inferior to ASIS and 2 in superior to the pubis symphysis which is midway between the two at MSP

AP Projection of Pelvis: Breathing Instructions

Suspend Respiration

AP Projection of Pelvis: SS

AP projection of the pelvic and of the head,

neck, trochanters and 1/3 or 1/4 of the shaft of femora

How to tell if the pelvis is rotated?

if the ilia aren't symmetric or the obturator foramens aren't symmetric

kVp for Pelvis, Anterior Pelvic Bones, and SI Joints

85-90

AP Oblique Femoral Necks (Modified Cleaves) is often called...

The Bilateral Frog Leg Position

AP Oblique Femoral Necks (Modified Cleaves): Patient Position

have patient flex hips and knees and

put soles of feet together and abduct thighs approximately 45 degrees from vertical to place the long axis of the femoral necks parallel to the IR

How much do we abduct the thighs for the AP Oblique Femoral Necks (Modified Cleaves)?

45 degrees

AP Oblique Femoral Necks (Modified Cleaves): CR

perpendicular to IR to enter 1 in superior to the pubic symphysis

AP Oblique Femoral Necks (Modified Cleaves): SS

bilateral image of the femoral heads, necks, and trochanteric areas does not have to include iliac crest !

AP Oblique Unilateral Femoral Neck: CR

perpendicular to the femoral neck

IR Size for SI Joints

10x12 LW

Method name for AP Axial "Outlet" Projection of Ant. Pelvic Bones ?

Taylor method

AP Axial "Outlet" (Taylor): CR for Males

25 degrees cephalad enters 2" distal to upper border of symphysis (20-35 degrees)

AP Axial "Outlet" (Taylor): CR for Females

40 degrees cephalad enters 2" distal to upper border of symphysis

AP Axial "Outlet" (Taylor): SS

superior and inferior rami with out foreshortening as seen with AP because CR is more perpendicular to rami

Method name for superoinferior axial "inlet" projection of ant. pelvic bones?

Bridgeman Method

Superoinferior Axial "Inlet" (Bridgeman): CR

40 degrees caudal entering at the level of the ASIS

Superoinferior Axial "Inlet" (Bridgeman): SS

axial projection of the pelvic ring or inlet in its entirety

Superoinferior Axial "Inlet" (Bridgeman): EC

medially superimposed superior and inferior rami of pubic bones, symmetric pubes and ischial spines

Method name for AP Axial SI Joints/ Lumbosacral Junction?

Ferguson Method

AP Axial SI Joints/ Lumbosacral Junction (Ferguson): CR

directed 30-35 degrees cephalic entering 1 1/2" superior to pubic symphysis or 2-2.5 inches inferior to ASIS at MSP

-males: 30 degrees

-females: 35 degrees

AP Axial SI Joints/ Lumbosacral Junction (Ferguson): SS/ EC

lumbrosacral joint and a symmetric image of both sacroiliac joints free of superimposition

-want to see open intervertebral disk space between L5 and S1 and both sacroiliac joints

AP Oblique of SI Joints (LPO/RPO): Patient Position

Patient supine; image demostrates the side thats up, elevate side being examined 25-30 degrees and support

AP Oblique LPO of the SI Joints will show which joint?

Right Joint

AP Oblique RPO of the SI Joints will show which joint?

Left Joint

AP Oblique of SI Joints (LPO/RPO): CR

directed perpendicular at level of ASIS entering 1" medial the elevated ASIS

AP Oblique of SI Joints (LPO/RPO): SS/EC

SI joint farthest from the IR and an oblique projection of the adjacent structures

-want to see open SI joint space and we do both for comparison

PA Oblique of SI Joints (LAO/RAO): Patient Position

patient prone, image will demostrate the side thats down, elevate side not being examined 23-30 degrees and support

PA Oblique LAO of the SI Joints will show which joint?

Left Joint (prone)

PA Oblique RAO of the SI Joints will show which joint?

Right Joint (prone)

PA Oblique of SI Joints (LAO/RAO): SS/EC

SI joint closest to the IR and an oblique projection of the adjacent structures

-want to see open SI joint space and we do both for comparison

Method name for AP Oblique of Acetabulum?

Judet Method

AP Oblique of Right Acetabulum (External Obl. (RPO)): Patient Position

45 degree obliquity with affected side down

AP Oblique of Right Acetabulum (External Obl. (RPO)): CR

perpendicular enters at pubic symphysis of affected side (side down)

AP Oblique of Right Acetabulum (Internal Obl. (LPO)): Patient Position

45 degree obliquity with unaffected side down and affected side up

AP Oblique of Right Acetabulum (Internal Obl. (LPO)): CR

perpendicular entering 2" inferior to ASIS of affected side (side up)

How to know if its The RPO External Oblique of the Acetabulum?

the ilium is flared when side is down (parallel to IR)

How to know if its The LPO Internal Oblique of the Acetabulum?

the ilium is perpendicular when affected side is up will look superimposed

AP Oblique of Right Acetabulum (Internal Obl. (LPO)): SS/ EC

to see fx of posterior rim and iliopubic column, the pubic bone is anteriorly located so we see the posterior rim

AP Oblique of Right Acetabulum (External Obl. (RPO)): SS/ EC

to see fx of anterior rim and ilioischial column, the ischium is posteriorly located so we see the anterior rim