Purpose
Observation of lumbar spine fracture, spinal stenosis, or tumor.
Lumbar spine alignment.
Hip spine syndrome.
Prior confirmation
Confirm whether the patient is to be radiographed in the standing or supine position, and AP or PA.
Remove any obstacles.
Positioning
Erect :
AP or PA orientation.
Spread the lower limbs shoulder-width apart.
The forehead and image receiving surfaces should be parallel to each other so that there is no twisting of the body.
Use a half-size cassette with the center height aligned with the iliac crest (Jacoby line, L4).
Supine :
Straighten the body so that the mid-sagittal plane passes through the center of the cassette.
Bend both knees to reduce lumbar kyphosis.
Align the center of the cassette with the third lumbar vertebra (two fingers headward of the Jacoby line).
CR, distance, field size
CR :
Erect : perpendicular to the 4th lumbar vertebra (intersection of the Jacobian line) and the midsagittal plane.
Supine : perpendicular to the 3rd lumbar vertebra (a point on the midsagittal plane at the level of the second transverse phalanx from the Jacoby line).
Distance : 100 to 150 cm.
Field size :
Erect : The 14×17 inch size field should be centered on the Jacobian line, with the lower edge aligned with the greater trochanter. The irradiation field should be extended to include the hip joint.
Supine : The irradiation field should be widened by 4 lateral fingers (8 lateral fingers on each side) and narrowed to include the psoas major muscle. The upper edge should include the 12th thoracic vertebra.
Exposure condition
75kV / 32mAs
Grid ( + )
Suspend respiration on expiration.
Image, check-point
Normal (Radiopaedia)
Erect : The upper border should extend to the 12th thoracic vertebra and the lower border should extend to the hip joint.
Supine : The superior border should extend to include the 12th thoracic vertebra and the inferior border should include the superior sacrum.
The spinous process shall be located in the center of the vertebral body.
The vertebral arch roots and transverse processes should be symmetrically drawn.
The vertebral canal space should be widely observed.
The psoas major muscle should be observable.
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