sacrum and coccyx/ SI joints test

For the AP and PA oblique projections of the SI joints, how much should you elevate the side up?

25-30 degrees

True or false:

For the AP and PA oblique projections of the SI joints, the long axis of the patients body should be perpendicular to the long axis of the exam table

False

True or false:

It may be difficult to use contact shielding on male patients for AP or PA oblique projections of the SI joints, so close collimation is important

False

For all SI joint and sacrum/ coccyx projections, how should the patient be instructed to breathe during the exposure?

Suspend respiration

Which of the following projections requires the arms to be placed in a position at right angles to the body?

Lateral sacrum or coccyx

Why should patients be placed supine for AP axial sacrum/ coccyx imaging whenever possible?

• to improve image sharpness

• To reduce magnification

• To reduce OID

For the AP/ PA axial projection of the sacrum/ coccyx, which plane is perpendicular to the IR?

MSP

Which of the following projections would require both ASISs to be equidistant from the tabletop or IR?

AP and PA axial sacrum or coccyx

Which of the following is true concerning the AP axial projections of the sacrum or coccyx?

Place a support under the patients knees

true or false:

Women cannot be shielded for the AP/PA axial projections of the sacrum/coccyx

True

Which of the following projections would require the patient to rest on their forearm and flexed knee of the elevated side?

PA oblique projection of the SI joints

for the lateral projection of the sacrum or coccyx, which plane is perpendicular to the IR?

More than one, but not all of the above

True or false:

For the lateral projection of the sacrum or coccyx, the knees and hips should be fully extended

False

What can be done to ensure that the long axis of the spine is horizontal and parallel to the IR for the lateral sacrum or coccyx projection?

Place a support under the body (usually at waist level)

Which of the following projections requires the CR to enter at the level of the ASIS and at a point 3.5 inches posterior to the ASIS?

Lateral sacrum

Which of the following projections requires the CR to enter at a point that is 3.5 inches posterior to the ASIS and 2 inches inferior to the ASIS?

Lateral coccyx

Which of the following projections requires a perpendicular CR?

• lateral sacrum

• Lateral coccyx

• AP oblique of the SI joints

Which of the following projections requires the CR to enter at a point that is 1 inch medial to the elevated ASIS?

AP oblique of the SI joints

Which of the following projections requires the CR to pass through a point that is 1 inch medial to the dependent ASIS?

PA oblique of the SI joints

Where should you center for an AP axial oblique of the SI joints?

1 inch medial and 1.5 inches distal to the elevated ASIS

How much and in what direction should you angle your CR for the AP axial oblique SI joint projection?

25 degrees cephalad

How much and in what direction should you angle your CR for the AP axial sacrum projection?

15 degrees cephalad

How much and in what direction should you angle your CR for the AP axial coccyx projection?

10 degrees caudad

Which of the following projections requires you to center at a point that is two inches superior to the symphysis pubis and MSP?

• AP axial sacrum

• AP axial coccyx

Which of the following projections requires you to center to the easily palpable coccyx?

PA axial coccyx

Which of the following projections requires you to center to the sacral curve?

PA axial sacrum

How much and in what direction should you angle your CR for a PA axial coccyx?

10 degrees cephalad

How much and in what direction should you angle your CR for a PA axial sacrum?

15 degrees caudad

Which of the following projections requires short scale contrast?

• AP axial or PA axial sacrum

• AP axial or PA axial coccyx

• Lateral sacrum

• Lateral coccyx

Which of the following are evaluation criteria for the lateral sacrum or lateral coccyx?

• sacrum and coccyx clearly seen with short scale contrast

• Use of tight collimation

• Closely superimposed posterior margins of the ischia and ilia

Which of the following are evaluation criteria for the AP or PA axial sacrum?

• sacrum seen free of superimposition of the pubic bones with short scale contrast

• Use of tight collimation

• Straightened sacral curve (sacrum free of foreshortening)

• Symmetrical ala, demonstrating no rotation