Sacrum X-Ray Positioning Master Guide

Comprehensive Clinical Reference for Standard AP Axial, Lateral, PA, and Sacroiliac Joint Views

Routine & Essential Sacrum Views

1. AP Axial Sacrum ViewStandard

Patient PositionSupine position with legs extended, proper support under head and knees for comfort and spinal alignment.

Beam DirectionAngled 15° cephalic, centered to a point approximately 5 cm superior to the pubic symphysis.

Clinical IndicationEvaluating sacral fractures, alignment, bone integrity, and sacral foramina without pelvic overlap.

2. Lateral Sacrum ViewStandard

Patient PositionTrue lateral recumbent position with knees flexed, placing support between knees/ankles to keep spine horizontal.

Beam DirectionPerpendicular to a point 8–10 cm posterior to ASIS at the level of the greater sciatic notch.

Clinical IndicationAssessment of sacral curvature, anterior/posterior displacement in fractures, and sacrococcygeal articulation.

3. PA Axial Sacrum ViewSpecial

Patient PositionProne position with a flat support placed under ankles or pelvis for patient stabilization.

Beam DirectionAngled 15° caudal, centered to exit at the level of the sacrum/third sacral segment.

Clinical IndicationAlternative projection to AP axial offering reduced patient gonadal dose in select diagnostic cases.

4. Coned-Down Lateral SacrumTargeted

Patient PositionTrue lateral recumbent position, tightly collimated specifically focusing on the sacrum area.

Beam DirectionPerpendicular to the center of the sacrum bone using high-detail collimation.

Clinical IndicationDetailed high-resolution visualization of fine hairline fractures or subtle bony lesions within the sacrum.

5. SI Joints Oblique ViewsOblique

Patient PositionPatient rotated 25° to 30° with the affected side up (RPO/LPO) or down (RAO/LAO).

Beam DirectionPerpendicular, centered 2.5 cm medial to the elevated ASIS.

Clinical IndicationDemonstrating the sacroiliac joint space, assessing for sacroiliitis, ankylosing spondylitis, or trauma.

6. SI Joints AP Axial ViewSpecial

Patient PositionSupine position with legs fully extended on the table surface.

Beam DirectionAngled 30° to 35° cephalic, centered along the midline at the level of ASIS.

Clinical IndicationSimultaneous bilateral visualization and comparison of both sacroiliac joints.

📌 Quick Jump Directory (Sacrum & SI Views)