AP – Standard Positioning
- Unless contraindicated (spinal precautions, medical directive or otherwise), the patient will be seated in bed in a semi-Fowler’s position. If repositioning of the patient is required, a suitably qualified nurse will be present to manually secure the endotracheal tube to prevent dislodgement.
- The digital imaging receptor will be placed behind the patient’s chest, ensuring the top of the imaging receptor is aligned above the level the cervical prominence.
- Radiographical markers indicating anatomical side should be placed on the image receptor.
- The mobile x-ray unit will be positioned such that the tube maintains a source-to-image-distance of approximately 180cm.
- The central ray will be directed at the level of thoracic vertebra level 7, which approximates to the skin landmark 8 to 10 cm below the jugular notch.
- The central ray will be angled caudally such that it is perpendicular to the long axis of the patient’s sternum, with modification of this angle decided by the radiographer so to ensure the patient’s clavicles are not projected over the apices of the patient’s lung field.
- The radiographer will then select the automatic exposure control method or choose appropriate exposure parameters considering the patient habitus.
- The tube will then be primed for exposure by depressing the trigger button halfway.
- The radiographer will then watch for chest expansion as the visual cue for triggering the exposure