ABSTRACT
Positioning for antero-posterior thoracic 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_80a.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/>
The patient is positioned supine on the X-ray table, with the median sagittal plane perpendicular to the table top and coincident with the midline of the Bucky.
The upper edge of the image detector or cassette (which should be at least 40 cm long for an adult), should be at a level just below the prominence of the thyroid cartilage to ensure that the upper thoracic vertebrae are included.
Exposure is made on arrested inspiration. This will cause the diaphragm to move down over the upper lumbar vertebra, thus reducing the chance of a large difference in density appearing on the image from superimposition of the lungs.
