AP axial view of Pelvis (inlet)
This axial projection to the pelvic ring allows assessment of pelvic trauma for posterior displacement or inward or outward rotation of the anterior pelvis. Patient is shielded with gonadal shielding if possible for males if essential pelvic anatomy will not obscure. Provide pillow for supine position, leg extended and place support under knees for comfort. During exposure respiration is suspended.Part Position and Central Ray
Align midsagittal plane to central ray and to midline of table or the cassette. The ASIS-to-tabletop distance is equal on both sides this will ensure no rotation of pelvis. Angle the CR caudad 40° it is near to become perpendicular to plane of inlet. CR is directed to the midline point it is at the level of ASIS. Center the cassette of projected central ray. Collimate the light apperture on four sides to area of interest.- IR size- 35 x 43 cm (14 x 17 inches)
- Moving or stationary grid
- 80 +- 5 kV range
- mAs 12
Radiographic Criteria - AP axial Pelvis "INLET"
Proper patient positioning with no rotation, the ischial spine are equal in size and shape and structures of pelvic ring or inlet or the superior aperture is demonstrated entirely in axial projection.Collimation and CR:
- Proper centering and angulation are evidenced by demonstration of the superimposed anterior and posterior portions of the pelvic ring.
- Center of pelvic inlet should be at center of collimated field.
- Lateral margins of collimation field should extend equally on both sides to just lateral to the femoral heads and acetabula.
- Superior and inferior margins of field should include the ala and the symphysis pubis, respectively.
- Optimal exposure demonstrates the superimposed anterior and posterior portions of the pelvic ring. Lateral aspects of ala generally are overexposed.
- Bony margins and trabecular markings of pubic and ischial bones appear sharp, indicating no motion.
