Chest X rays (CXRs)
By Izzy Pines (epines38@gmail.com)
X ray basics
 Gas = Black
 Fat = Dark grey
 Water = Light grey
 Bone/metal = White
DRS ABCDE Algorithm from LITFL
LITFL’s basic CXR flow chart
D – Details
 Patient name, age/DOB, gender
 Indication for study
 Type of film –
o AP/PA
o portable
o seated, supine, standing
o inspiratory or expiratory
o L/R marker is correct
R – RIPE (image quality)
 Rotation
o look to see if the medial clavicles are equidistant from the spinous process
 Inspiration
o 5-6 anterior ribs in midclavicular line or 8-10 posterior ribs above the diaphragm
 Picture
o Straight or oblique
o entire lung fields, scapulae outside lung fields
o angulation (tilt in vertical plane)
 Exposure (penetration)
o Can see disc spaces and spinous processes to about T4
o Left hemidiaphragm is visible through the cardiac shadow
S – Soft tissue and bones
 Look for:
o Symmetry, fractures, dislocations, lytic lesions, densities in the
 Ribs
 trace along each posterior rib on one side, then the other
 trace along the lateral and anterior ribs on one side, then the other
 Sternum
 Clavicles
 Trace the cortex of the bone
 Vertebral bodies
 Are they rectangular and similar in height?
 AC or glenohumeral joints
o Symmetry, swelling, loss of tissue planes, presence of subcutaneous air, or masses in the
soft tissue
o Breast shadows
A – Airway
 Trachea position – start at top and trace to carina.
o Is it straight and midline? Is the carina wide (>100 degrees)?
 Identify the right main bronchus, and left main bronchus.
o Is there narrowing or dilatation?
B – Breathing
 Lung fields
o Symmetry
 Similar volume
 Apices (ABOVE the clavicles), upper, middle, and lower zones are symmetrical
 Pulmonary infiltrates (interstitial vs alveolar pattern)
 Lesions – coin or cavitary
 Normal lung behind the heart
o Vasculature
 should be able to follow it peripherally to about 2cm of the pleural surface
 vessels at the bases should be larger than apices
o Lateral margins
 abnormal opacity/lucency, atelectasis, collapse, consolidation, bullae
 Pneumothorax (especially at apices. ZOOM IN!)
o Horizontal fissure on right Lung
 Pleura
o Pleural reflections
o Pleural thickening
C – Circulation
 Heart position (2/3 on left side of CXR)
 Heart size (normal if <50% of thoracic width on PA film, <60% on AP film)
 Heart borders
o Are they sharp?
o right border = right atrium
o Left border = left atrium and ventricle
 Aortic arch/knob
 Hilum
o should be a T6-7 level
o Left should be higher and squarer than right
 Presence of any paratracheal or mediastinal masses or adenopathy
 Mediastinal width
o should be < 8cm on a PA film
 Calcification of vessels

Presence of hiatal hernia
o You will see retrocardiac air-fluid level
D – Diaphragm
 Hemidiaphragm levels (right will be higher than left by about 2.5cm or 1 intercostal space)
 Diaphragm shape
 Cardiophrenic and costophrenic angles (clear and sharp)
 Gastric bubble and air in colon
 Subdiaphragmatic air (should NOT be there. Means likely GI perforation)
E - Extras
 Tubes
o ET tube
 Should be 5cm from the carina (halfway btwn sternal notch and carina)
 width is 2/3 tracheal diameter
 cuff should not expand the trachea
o CVP line
o NG tube
 descends the thorax in the midline
 bisects the carina
 crosses the diaphragm in the midline
 the tip sits below the diaphragm
o Chest tube
o PICC line
 Should sit at the junction of the SVC and right atrium
 Trace the line from the arm towards the axilla
 Trace the line under the clavicle towards the SVC
 Make sure that the line does not turn cranially towards the neck vessels
 trace the line through the right paratracheal soft tissue towards the heart
 EKG leads
 AICD
Other Algorithms (Reference)
1) Reporter Method
 Who: correct patient
 When: correct day
 Why: what is the indication for the test / what are we looking for?
 What: what is the image of?
2) ABCDEFGHI Method
 A Assess quality/Airway (midline, patent)
 B Bones (eg, fractures, lytic lesions)
 C Cardiac silhouette size
 D Diaphragm (eg, flat or elevated hemidiaphragm)





E Edges (borders) of the heart (to rule out lingular and left middle lobe pneumonia or
infiltrates)
F Fields (lung fields well inflated; no effusions, infiltrates, or nodules noted)
G Gastric bubble (present, obscured, absent)
H Hilum (nodes, masses)
I Instrumentation (eg, lines, tubes)
3) ABC Method
 Airways
o Trachea
o Hilar
 Breathing & Bones
o Lung fields, pleura. Costophrenic Angles.
o Bones – destruction, #s
 Circulation & Soft tissues.
o Mediastinum – width.
4) DCBAA Method
 D – Documents
 C – Chest
o Compare lungs
o Airway (right place, deviation)
o Mediastinum
o Diaphragm
o Pleura
 B – Bones
o Look at all the bones.
o Pattern recognition
 A - Abdomen
o Frees gas - erect Chest X-Ray under diaphragm
 A - And Areas
o Additional areas that you wouldn't normally look at
Resources:
 http://radiopaedia.org/articles/chest-x-ray-basic-an-approach
 Interactive module from U of Miami:
http://radiology.med.miami.edu/prebuilt/radiology_edu/rad_interaccxr/CXR0413.html
 CXR module from U of Kentucky IM dept:
http://medicine.mc.uky.edu/chestradiology/chestnew.swf
 http://www.learningradiology.com/medstudents/medstudtoc.htm