Femoral Neck AP Oblique (Modified Cleaves) is a radiography positioning projection of the Pelvis. Supine, hips flexed 40-45 degrees, knees flexed 60 degrees, feet together. SID 40". The centering point is located 1 inch above pubic symphysis at midline, between both femoral necks.. The central ray is perpendicular to ir, 1 inch above pubic symphysis.. Image-quality criteria include bilateral femoral necks shown without foreshortening., femoral heads and acetabula open and symmetric.. Standard exposure ranges from 75 to 85 kVp, 12 to 20 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Bilateral femoral heads.
- Bilateral femoral necks without foreshortening.
- Bilateral acetabula.
- Bilateral greater and lesser trochanters.
- Pubic bones.
- Ischial spines.
Patient preparation
- Verify patient identity using two identifiers.
- Remove all radiopaque objects from hip and pelvic region.
- Place patient supine on table.
- Flex hips 40-45 degrees, flex knees 60 degrees.
- Place feet together; support knees if needed.
Position & centering point
1 inch above pubic symphysis at midline, between both femoral necks.
Central ray
Perpendicular to IR, 1 inch above pubic symphysis.
Exposure / technique
- kVp
- 75–85
- mAs
- 12–20
- SID
- 40" (102 cm)
- Notes
- Grid required. Bilateral femoral necks shown without superimposition.
Image-quality criteria
- Bilateral femoral necks shown without foreshortening.
- Femoral heads and acetabula open and symmetric.
- Both feet together without motion.
- Bone trabeculae sharp, no motion blur.
- No pelvic rotation; ischial spines symmetric.
- Collimation: 14 x 17 inch crosswise.
Common errors / ARRT traps
- 1 Insufficient hip flexion elongates femoral necks and reduces openness.
- 2 Asymmetric foot placement foreshortens one femoral neck.
- 3 Pelvic tilt makes bilateral necks asymmetric in length.
- 4 Off-centered CR above pubis limits visualization of acetabula.
Clinical indications
- Bilateral femoral neck fracture evaluation.
- Femoral neck anatomy study.
- Hip osteoarthritis assessment.
- Post-operative femoral neck fixation check.
Aligned to the 2025 ARRT Content Specifications.