Sacrum - AP axial & Lateral

Bowel should be prepped and bladder emptied before examination. T/F

true

Patient/part position for an AP Axial Sacrum/Coccyx:

• supine

• MSP in midline of table

• ASIS equidistant from grid

• arms in comfortable, symmetric position out of field

• support knees, if supine

How else can the patient be positioned other than an AP?

may also be performed with patient prone (PA axial projection), if needed for comfort

Where is the central ray placed for an AP Axial Sacrum if the patient is supine?

• 15 degrees cephalad

• enters MSP at 2” superior to pubic symphysis

Where is the central ray placed for an AP Axial Sacrum if the patient is prone?

• 15 degrees caudad

• enters MSP at level of sacral curve

What is the collimation size for an AP Axial and Lateral Sacrum?

radiation field 10 × 12 inches

What structures are shown for an AP Axial Sacrum?

the sacrum free of superimposition

What is the Evaluation Criteria for an AP Axial Sacrum?

• sacrum centered and seen in its entirety

• sacrum free of foreshortening, with the sacral curvature straightened

• pubic bones not overlapping the sacrum

• no rotation of the sacrum, as demonstrated by symmetric alae

What is the breathing technique for an AP Axial Sacrum?

suspend

Part/position for the Lateral Sacrum/Coccyx projection?

• recumbent lateral

• hips and knees flexed for comfort

• arms at right angle to body

• knees superimposed

• support spine to horizontal position

• lead shield behind patient

Where is the central ray placed for the Lateral Sacrum projection?

• perpendicular to level of ASIS

• 3½” posterior

Where is the central ray placed for the Lateral Coccyx projection?

• perpendicular and 2” inferior to ASIS

• 3½'“ posterior

What are the structures shown for the Lateral Sacrum/Coccyx projection?

sacrum and coccyx

What are the breathing instructions for the Lateral Sacrum/Coccyx projection?

suspend

Where is the central ray placed for an AP Axial Coccyx if the patient is supine?

• angled 10 degrees caudad

• MSP at 2” superior to pubic symphysis

Where is the central ray placed for an AP Axial Coccyx if the patient is prone?

• 10 degrees cephalad

• enters MSP at coccyx

What is the collimation size for the AP Axial Coccyx projection?

radiation field 8 × 10 inches