Projections, CRs, positioning for Sacrum, Coccyx, and SI Joints

Question 1

AP Axial: Sacrum (CR, pt positioning, anatomy)

Answer 1

CR: 2” superior to pubic symphysis w/ 15° cephalad angle
position: supine no rotation
anatomy: sacrum, SI joints, disk spaces, L5-S1 joint

Question 2

Lateral: Sacrum (CR, pt positioning, anatomy)°

Answer 2

CR: 3-4” posterior to upside ASIS
position: lateral recumbent w/ knees and hips flexed
anatomy: sacrum and L5-S1 joint

Question 3

AP axial: Coccyx (CR, pt positioning, anatomy)

Answer 3

CR: 2” superior to pubic symphysis w/ 10° caudal angle
position: supine w/ support under knees
anatomy: coccyx, sacrum, SI joints, disk spaces, L5-S1 joint

Question 4

Lateral: Coccyx (CR, pt positioning, anatomy)

Answer 4

CR: 3-4” posterior to upside ASIS
position: lateral recumbent w/ knees and hips flexed
anatomy: coccyx, sacrum and L5-S1 joint

Question 5

AP axial: SI Joints (CR, pt positioning, anatomy)

Answer 5

CR: 2” below ASIS (males - 30° cephalad, females - 35° cephalad)
position: supine no rotation
anatomy: SI joints, L5-S, disk spaces

Question 6

Oblique: SI Joints (CR, pt positioning, anatomy)

Answer 6

CR: 1” medial to ASIS
position: supine 25-30° post. oblique
anatomy: SI joints, L5-S1, disk spaces