ABSTRACT
Positioning for antero-posterior lumbar spine projection. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315382210/8ca82e7c-bd07-4171-b4f5-ebaded57b5b3/content/fig2_51a.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>
The patient lies supine on the Bucky table, with the median sagittal plane coincident with, and at right angles to, the midline of the table and Bucky.
The anterior superior iliac spines should be equidistant from the table top.
The hips and knees are flexed, and the feet are placed with their plantar aspect on the table top to reduce the lumbar arch and bring the lumbar region of the vertebral column parallel to the receptor.
If a CR cassette is being used, it should be large enough to include the lower thoracic vertebrae and the sacro-iliac joints and is centred on the level of the lower costal margin.
The exposure should be made on arrested expiration, as the diaphragm will cause the diaphragm to move superiorly. The air within the lungs would otherwise cause a large difference in density and poor contrast between the upper and lower lumbar vertebrae.
