Chest - AP Supine

Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Chest - AP Supine (when not able to sit or stand)
Area Covered	Lung fields, apices, costophrenic angles, heart
Pathology shown	The placement of various medical equipment can be seen, such as, Central Venous Catheters (CVC), Nasogastric Tubes (NGT), Chest Tubes, Endotracheal Tubes, Swan-Ganz catheters and Pacemakers It is important to note that pleural effusions are best seen in an Erect Chest X-ray. In a Supine Chest X-ray the fluid is dispersed evenly through the lung fields, and so air-fluid levels will not show.
Radiographic Anatomy	Chest Radiographic Anatomy
IR Size & Orientation	35 x 43 cm Landscape usually, but may be portrait depending on body habitus 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 /not for most portable CXR's
Filter	No
Exposure	85 kVp 2 mAs no grid 100 kVp 4 mAs with grid
FFD / SID	As large as possible up to 180 cm This may be helped by having the bed as low as possible and the X-ray tube as high as you can, giving an FFD/SID up to 180 cm
Central Ray	Directed to the midsaggital plane, approximately 10 cm inferior to the jugular notch. (This is at the level of T7). Perpendicular to the coronal plane and the IR
Collimation	Centre: 10 cm inferior to the jugular notch 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 AP
Shielding	Gonadal (check your department's policy guidelines)
Respiration	On suspended deep inspiration
Positioning	Centre the midsaggital plane of the patient to the midline of the IR Ensure the midsaggital plane is perpendicular to the IR, that is, the patient is lying flat and is not rotated If possible, move aside as many artifacts (tubes etc.) that may be lying over the chest Arms relaxed at the sides If possible, pronate hands and bring elbows away from the sides of the body to help clear the scapulae of the lung fields Adjust the height of the IR to 5cm (2 inches) above the shoulders Raise the chin if this is superimposing over the chest
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 9th 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
Special Notes	PA Erect Chest vs AP Supine Chest Where possible a PA Erect should be done instead of the AP Supine view. The AP Supine Chest view is taken when the patient is unable to be safely moved into the upright position. Differences or disadvantages of the AP Supine Chest view are; Lung fields are shortened the heart is magnified the ribs may appear more horizontal air-fluid levels are not seen the clavicles are projected higher up