Chest -Lateral Decubitus

Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Chest - Lateral Decubitus (either AP or PA)
Area Covered	Lung fields, apices, costophrenic angles, heart
Pathology shown	This projection is used to detect any air and fluid levels present in the pleural cavity. Air in the case of a pneumothorax or fluid in the case of pleural effusions. It also shows changes in fluid position from PA/AP view and reveals any previously obscured pulmonary areas
Radiographic Anatomy	Chest Radiographic Anatomy
IR Size & Orientation	35 x 43 cm Usually portrait (the long axis of the IR is parallel to the long axis of the torso) D.R. may cover 43 x 43 cm
Film / Screen Combination	Regular (CR and DR as recommended by manufacturer)
Bucky / Grid	Moving or Stationary Grid, portable X-ray may be done without grid
Filter	No
Exposure	85 kVp 2.5 mAs no grid 100 kv 4 mAs with grid
FFD / SID	180cm
Central Ray	Directed to the midsaggital plane at the level of T7 Perpendicular to the IR
Collimation	Centre: T7 or the inferior border of the scapula Shutter A: Open to approximately 5cm above the shoulder to include upper airway Shutter B: Open to the level of the acromioclavicular joints (AC joints) laterally. This will include the lung fields laterally.
Markers	Superior and Lateral Marker orientation either AP or PA, depending on the patient's positioning Marker indicating the side which is up
Shielding	Gonadal (check your department's policy guidelines)
Respiration	On suspended deep inspiration
Positioning	Position the patient in the lateral decubitus position usually AP, as this is often easier for the patient with either the left or right side up (see Special Notes below) ensure that the side that is touching the bed or table is slightly raised, perhaps using a sponge, so that the entire lungs fields are included on the image and are not 'cut off'. If possible, wait at least 5 minutes before taking the image to allow gas fluid levels to form Bring the patient's arms above their head so they do not superimpose over the thorax Check that the patient is in a true lateral position, and that the coronal plane is parallel to the IR
Critique PACEMAN	Positioning No rotation as evidenced by the medial ends of the clavicles equidistant from the spine the clavicles are in the same horizontal plane The lungs fields are clear of the scapulae The 10th posterior ribs will be visualised above the diaphragm on full inspiration Area Covered Lungs fields, apices, costophrenic angles, heart Collimation Centre: T7 Thoracic vertebra Shutter A: Open to show the lung apices superiorly and the costophrenic angles inferiorly Shutter B: Open to show the lung fields laterally Exposure There should be adequate exposure so that the ribs and thoracic vertebrae are seen faintly through the heart vascular lungs markings are shown air and fluid levels are able to be seen
Special Notes	Left vs Right Lateral Decubitus Chest For possible fluid - put the suspected side down For possible air - put the suspected side up Annotations Indicate "Decubutis" on the image as well as the side up