chest

• Radiographic Projections of the Chest

  • PA Projection
  • Lateral Projection
  • AP Projection (Supine/Semi-erect position)
  • AP Projection (Lateral decubitus position)
  • Lordotic/AP Axial Projection
  • PA and AP Oblique Projection
• Basic/Routine Projections

  PA & Lateral
• PA Projection

  1. Shoulders rotated forward against erect Bucky to allow scapula to move laterally clear of lungs field

  2. Depress shoulders downward to move clavicles below the apices

  3. Clear large pendulous breast from lungs field – if necessary
• Part Positioning

  Align MSP with CR and with midline of IR with equal margins between lateral thorax and sides of IR. Ensure no rotation of thorax by placing the MCP parallel to the IR
• Central Ray

  CR perpendicular to film/IR and centered to MSP
• Centering Point

  At level of T7 (inferior angle of scapula), measure 7-8 inches (18-20 cm) below vertebra prominence
• Collimation

  • Superior – vertebra prominence
  • Sides – lateral wall of the thorax
  • Inferior – lower costal margin
• Respiration

  Exposure made at end of 2nd full inspiration
• Technical Factors


  • Film/IR size : 14x17 inches (35x43 cm), lengthwise or crosswise
  • Grid: 90-120 kVp , mAs: 2-3
  • Non-grid: 65-85 kVp, mAs: 5-6
  • Grid: 100-150 kVp, mAs: 3-4
  • Non-grid: 80-95 kVp, mAs: 5-7
  • FFD/SID : 180 cm/72 inches
  • Lead apron or gonad shielding to protect gonadal area
• Radiographic Anatomy (Structures seen)

  • Trachea
  • Right and left sternoclavicular joint
  • Right and left lung
  • Right and left costophrenic angle
  • Right and left apex
  • Right and left clavicle
  • Aortic arch
  • Heart
  • Diaphragm
  • Ribs

  
• Evaluation Criteria

  • The apices, costophrenic angles, and lateral margins of the ribs are included in the collimated field
  • The spine should be centered crosswise on the film; middle of collimation field is on T7
  • No rotation – Both medial ends of clavicle equidistant from spine; Distance from the lateral borders of the ribs to the spine should be symmetrical on each side, from upper to lower rib cage
  • Both scapula are clear of lungs area if shoulders are rotated forward sufficiently
  • Full inspiration should result in at least 10 posterior ribs visualized above diaphragm
  • No motion should result in sharp outlines of diaphragm and heart borders
  • Optimum exposure and sufficient long contrast scale (low contrast) should visualized the fine vascular lungs markings through the heart
  • Enough penetration (kVp) – Faint outlines of at least the mid and upper thoracic vertebra and posterior ribs through the heart and mediastinal structures
  • Patient ID and anatomical markers should be clearly seen without superimposing the area of interest

  
• Lateral Projection

  Patient erect, left side against cassette (unless right side is indicated) without leaning, weight evenly distributed on both feet, arm raised above head and chin up
• Part Position

  MCP aligned and perpendicular to midline of erect bucky. MSP parallel to film. Ensure no rotation by checking that posterior aspect of thorax is perpendicular to cassette
• Central Ray

  CR perpendicular to film and centered to MCP at level of T7 (inferior angle of scapula); 1 thumb-little finger breath from vertebra prominence
• Collimation

  Laterally - to include the spine and sternum, Superior – to include apices, Inferior – to include diaphragm
• Radiographic Anatomy (Structures seen)

  • Apices, superimposed
  • Aortic arch
  • Lungs, superimposed
  • Right hemidiaphragm
  • Sternum
  • Heart
  • Left hemidiaphragm

  
• Evaluation Criteria

  • No rotation – Ribs posterior to vertebral column should be directly superimposed; costophrenic angle should be aligned and superimposed
  • Chin and arms should be elevated sufficiently to prevent excessive soft tissue from superimposing apices
  • Images should include lung apices at the top and costophrenic angles on the lower margin of the film
  • The hilar region should be approximately at the center of the film
  • Sharp outlines of the diaphragm and lung markings
  • Sufficient exposure to visualize lung markings thru the heart shadow and upper lung areas, without overexposing other regions
  • Patient ID and anatomical markers should be clearly seen without superimposing the area of interest

  
• AP Projection

  Done if patient is unable to do erect position
• Technical Factors

  • Film size – 14x17 in (35x43 cm), lengthwise or crosswise
  • Exp factors – kVp: 100-120 kVp (grid); 80-95 kVp (non-grid)
  • FFD – 100 cm
  • Shielding – cover gonad area
• Patient Position

  Patient supine with MSP aligned and perpendicular to midline of table, Roll shoulder forward as much as possible by rotating arm medially
• Part Position

  Position cassette in bucky tray with the top border at 2 in superior to patient shoulder, Extend neck slightly
• Central Ray

  CR perpendicular to the MSP at centered at the level of T7 (midpoint between sternal angle and xifisternum)
• Collimation

  Superior – vertebra prominence, Sides – lateral wall of the thorax, Inferior – lower costal margin
• Respiration

  Exposure made at the end of 2nd full inspiration
• Evaluation Criteria

  • The heart will appear larger due to increased magnification from a shorter FFD
  • Usually there will not be as full an inspiration, with only 8 or 9 posterior ribs visualised above diaphragm. Thus, the lungs will appear more dense because the lungs are not fully aerated

  
• Lateral Decubitus Projection

  Done if need to see air-fluid levels, but patient is unable to assume erect position
• Patient Position

  Use a radiolucent pad under the patient; place pillows under head, Patient lying on right side for right lateral decubitus, or left side for left lateral decubitus, Arms above head to clear lung field; place back of patient firmly against film holder, Flex knees slightly and ensure pelvis and shoulders are parallel to film with no body rotation
• Part Position

  Adjust height of film holder to center thorax to film; top border of film should be at 2 in superior of patient shoulder
• Collimation

  Collimate to area of lungs field
• Notes

  • Place appropriate marker to indicate which side is up
  • For possible fluid in pleural cavity (pleural effusion), the suspected side should be down
  • For possible small amount of air in pleural cavity (pneumothorax) the affected side should be up
  • Make sure the side of the chest that is down is not cut off
  • Allow about 10 minutes before taking the exposure, to give enough time for the air/fluid to settle up/down
• Evaluation Criteriaof Lateral


  • Same as PA Projection
• AP Lordotic Projection


  To project the clavicles superior to the apex region of the lungs, thus the apex will be visualized without superimposition with the clavicle
• Patient Position

  Patient stand about one foot away from film holder and lean back with shoulders, neck and back of head against film holder, Rest both hands on hips, palms out and shoulders rolled forward, Align and center MSP to midline of the cassette
• Collimation

  Collimate to area of lungs of interest
• Evaluation Criteria

  • Clavicles should appear nearly horizontal and superior to apices
  • Ribs appear distorted with posterior ribs appearing nearly horizontal
  • Other criteria will be the same as for AP projection

  
• PA Oblique Projection


  To evaluate suspicious areas seen on the PA or lateral projection or to evaluate the heart
• Technical Factors

  • Film size – 14x17 in (35x43 cm), lengthwise
  • Exp factors – kVp: 100-150 kVp (grid); 80-95 kVp (non-grid)
  • FFD – 180 cm
• Patient Position

  Patient erect, rotated 45 degrees with left anterior shoulder against film for LAO and vice versa, Flex arm nearest film holder and place hand on hip, palm out, Raise opposite arm to clear lung field and rest on hand on film holder and look straight ahead and keep chin raised
• Central Ray

  At level of T7 midway between lateral wall of the raised side and midline of patient
• Collimation

  Entire lung field from apex to base