Hip Axiolateral is a radiography positioning projection of the Pelvis. Danelius-Miller. Supine, affected leg extended, opposite leg raised out of the field. Horizontal cross-table CR. SID 40". The centering point is located at the femoral neck, about 2.5 inches distal to the midpoint of the ASIS-symphysis line, entered from the medial thigh (groin). The central ray is horizontal (cross-table), directed perpendicular to the femoral neck. Image-quality criteria include entire femoral head and neck, trochanter and acetabulum visualized, with any prosthetic device in its entirety, femoral neck shown with minimal foreshortening. A sample technique is 90 kVp with DR 32 or CR 71 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Femoral head.
- Femoral neck shown with minimal foreshortening.
- Greater trochanter entering view from lateral.
- Acetabulum, though the most proximal head and acetabulum may not show on a patient with thick thighs.
- Proximal femoral shaft.
- Hip joint space.
Patient preparation
- Verify patient identity using two identifiers.
- Remove all radiopaque objects from hip region.
- Place patient supine on table.
- Keep the affected leg extended. Do not rotate it if a fracture is possible.
- Flex the unaffected hip and knee and raise the leg vertically out of the field.
Position & centering point
At the femoral neck, about 2.5 inches distal to the midpoint of the ASIS-symphysis line, entered from the medial thigh (groin).
Central ray
Horizontal (cross-table), directed perpendicular to the femoral neck.
Exposure / technique
- kVp
- 90
- mAs
- DR 32 / CR 71
- SID
- 40" (102 cm)
- Notes
- Grid required. CR horizontal and perpendicular to the femoral neck (limb internally rotated 15-20 degrees unless contraindicated; do not rotate the leg when a fracture is possible); the IR is tilted parallel to the neck and perpendicular to the CR, never the beam. Sample technique: DR 32 / CR 71 mAs at 90 kVp, 40 in SID, for a 24 cm part (Merrill's sample chart). Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- Entire femoral head and neck, trochanter and acetabulum visualized, with any prosthetic device in its entirety.
- Femoral neck shown with minimal foreshortening.
- Greater trochanter visible, entering view laterally from hip.
- Only the most distal part of the femoral neck superimposed by the greater trochanter.
- Bone trabeculae sharp, no motion blur.
- Collimated on four sides to the area of interest; no grid lines visible.
Common errors
- 1 CR not perpendicular to both the femoral neck and the IR.
- 2 Grid cutoff from improper IR or grid alignment to the horizontal beam.
- 3 Pelvis rotated: check for equal ASIS-to-table distance.
- 4 Unaffected leg not raised enough, so its soft tissue superimposes the affected hip.
Clinical indications
- Hip fracture evaluation (femoral neck fracture assessment).
- Dislocation assessment in trauma when the affected leg cannot be moved.
- Post-operative hip prosthesis position check.