Purpose
If imaging in an upright or seated position is not possible, adopting the left lateral decubitus position can serve as an alternative approach for observing the upper abdomen, gas, and mirror images.
This position (left lateral decubitus) facilitates the movement of air and allows abnormal gas to be visualized away from the gastric bubble, closer to the liver.
Prior confirmation
Whether to perform imaging in the anterior-posterior (AP) direction or posterior-anterior (PA) direction depends on the specific clinical scenario and the target area being imaged.
To allow for air ascent and fluid level formation, it is recommended to wait for 5-15 minutes while maintaining the lateral decubitus position.
Remove any obstructions that may interfere with the imaging, such as tubes, chucks, buttons, and other objects.
Positioning
Left lateral decubitus position.
Place a 5 cm cushion under the body to elevate and align the mid-sagittal plane parallel to the floor.
Minimize shoulder and pelvic rotation to align the coronal plane parallel to the cassette.
Slightly flex the knees to stabilize the posture.
Raise both arms to keep them outside the radiation field.
Use a 14×17 cassette and position the top edge at the level of the axilla.
Place an RL marker.
CR, distance, field size
CR : Horizontal beam directed towards the center of the cassette.
Distance : 100-150 cm.
Field size : In the cranio-caudal direction, use a 17 inches size, and in the left-right direction, narrow it down to the skin surface.
Exposure condition
70kV / 32mAs
Grid ( + )
Full expiration. (After complete exhalation, wait for 1 second before making the exposure.)
Image, check-point
Radiopaedia
Ensure that both the left and right diaphragms are projected on the image.
Make sure the vertebral bodies are clearly projected at the center of the image without any curvature.
Verify that the iliac bones are symmetrically projected on both sides.
Ensure that the edges of the gas image are sharp and there is no blurring.
Videos
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