This document is a presentation on interpreting chest X-rays, covering fundamental principles, image quality assessment, and a systematic ABCDE approach to evaluation. Key factors include proper patient positioning, exposure quality, and recognizing pathologies like pulmonary edema and pneumothorax. It emphasizes the importance of documenting findings accurately and understanding clinical context for effective diagnosis.

1. CHEST X-RAY
ART OF DIAGNOSIS
Presenter: Dr. Ravi Rokaya
Moderator: Dr. Bidesh Bista

2. Contents
• Basics of X-rays
• Assessing image quality
• Approach to interpreting X-ray
• X-ray review
• Documenting details
• Take home message

3. Basics of an X-ray
• X-rays use radiation (photons) to create 2D images
• Structure that are less dense appear dark/black (eg lungs)
• Structure that are more dense appear white (eg bones, tumor,
metals)
• Structure that are medium dense appear grey (eg soft tissues)

4. Before you begin
• Patient details (name, DOB, hospital number)
• Date & time x-ray was performed
• Previous imaging - for comparison

5. Assess image quality
RIPE
• R – Rotation
• I – Inspiration
• P – Projection
• E – Exposure

6. Rotation
• Vertebral bodies & spinous
processes should be vertically
aligned.
• The medial aspect of each
clavicle should be equidistant
from the spinous processes.

7. Rotation

8. Inspiration
• If inspiration is adequate, the
following should be visible:
5-6 anterior ribs
Both lung apices
Both costophrenic angles
Lateral rib edges

9. Projection

10. Posterior-Anterior (PA) Position
• The standard position for obtaining a routine chest radiograph.
• Patient stands upright with the anterior wall of chest placed against
the front of the film.
• Usually taken with the patient in full inspiration
• The PA film is viewed as if the patient is standing in front of you

11. Anterior-Posterior (AP) Projection
• Used when the patient is debilitated, immobilized, or unable to
cooperate with the PA procedure
• Film is placed behind the patient's back with the patient in a supine
position
• The scapulae are usually visible in the lung fields because they are not
rotated out of the view as they are in a PA

12. Lateral Projection
• Patient stands upright with the left side of the chest against the film
and the arms raised over the head
• Allows the viewer to see behind the heart and diaphragmatic dome
• Typically used in conjunction with a PA view of the same side of chest
to help determine the three-dimensional position of organs or
abnormal densities

13. Exposure
• In a properly exposed chest radiograph:
-the lower thoracic vertebrae should be
visible through the heart
-the broncho vascular structures behind
heart (trachea, aortic arch, pulmonary
arteries, etc.) should be seen.

14. Underexposure
• In an underexposed chest radiograph,
the cardiac shadow is opaque, with
little or no visibility of the thoracic
vertebrae.
• The lungs may appear much denser
and whiter, gives appearance of
infiltrates.

15. Overexposure
• With greater exposure of the chest
radiograph, the heart becomes more
radiolucent and the lungs become
proportionately darker.
• Often gives the appearance of lacking
lung tissue, as would be seen in a
condition such as emphysema.

16. ABCDE Approach
• Airway | trachea, carina, bronchi & hilar structures
• Breathing | lungs & pleura
• Cardiac | heart size & borders
• Diaphragm | assessment of diaphragm & costophrenic angles
• Everything else | mediastinal contours, bones, soft tissues, tubes,
valves, pacemakers & review areas

17. Airway
• Airway structures to
examine:
Trachea
Carina & bronchi
Hilar structures

18. Trachea
Inspect the trachea for signs of deviation
True deviation Apparent deviation
Large pleural effusion
Tension pneumothorax
Lobar collapse
Rotation of the patient

21. Carina and Bronchi
• The carina is located at the point
where trachea divides into the
Left & Right main bronchus.

22. Hilar structures
• The Hilar contain
 Pulmonary vessels
 Major bronchi
 Lymph nodes

23. • Hilar enlargement can be unilateral
or bilateral
• Bilateral enlargement –
1. Metastasis
2. Tuberculosis
3. Sarcoidosis
4. Lymphoma
5. Histoplasmosis

24. • Hilar enlargement can be unilateral
or bilateral
• Unilateral enlargement –
• Bronchogenic cyst
• Lung Cancer
• Large right pulmonary artery
• Aneurysm of descending aorta

25. Breathing

26. Breathing
• Divide each of the lungs into three zones & inspect each zone,
noting any asymmetry.

28. Lungs
• Abnormalities may include:
Pulmonary edema
Consolidation/Malignancy
Pneumothorax

29. Pulmonary Edema
• Common findings may include:
Air space opacification (bat wing distribution)
Kerley B lines
Pleural effusions (look for costophrenic blunting)
Fluid in interlobular fissures

30. Fig: Pulmonary edema

31. • Common causes of pulmonary edema includes:
Left heart failure
Mitral regurgitation
Fluid overload

34. Pneumothorax

37. Pleura
• Membrane surrounding the lungs
• Usually not visible in healthy individuals
• But can be visible when thickened

38. • Common causes of pleural
thickening:
• Mesothelioma
Pleural Thickening

39. • Pneumothorax

40. • Hydrothorax collection
of fluid in pleural space

41. • Haemothorax Collection
of blood in pleural space

42. • Empyema Collection
of pus in pleural space

43. Cardia
• Assess the following:
Cardiac size
Cardiac borders

44. Cardiac size
• Normal <50% of the thoracic
window
• >50% of thoracic window
Cardiomegaly
Accurate assessment requires PA chest x-ray
As AP films exaggerate the size of the heart

46. Causes of cardiomegaly
• There are many different causes of
cardiomegaly:
Valvular heart diseases
Coronary artery diseases
Pulmonary hypertension
Congenital heart diseases

47. Cardiac borders
• In healthy individuals the borders
of the heart should be clearly
visible & well-defined.

52. Diaphragm
• Assessing the diaphragm:
Left & right hemidiaphragm
Costophrenic angles

53. Hemidiaphragm
• Right hemidiaphragm higher than the left
due to presence of liver below
• Stomach sits under the left hemidiaphragm
and gastric bubble can be visualized

54. • Pneumoperitoneum= accumulation of air
under the diaphragm
• Results in the separation of the diaphragm
from liver.
• Often secondary to a bowel perforation

56. Costophrenic angles
• The costophrenic angles reflect the dome
shape of hemidiaphragm as it meets the
lateral chest wall.

57. • The loss of this angle is termed as
costophrenic blunting & causes
includes:
Pleural effusion
Consolidation
Hyperinflation (e.g. asthma copd)

58. Everything else
Review everything else:
Mediastinal contours
Aortic knuckle
Aortopulmonary window
Bones & soft tissues
Tubes, valves & pacemakers
Review areas

59. Mediastinal contours

60. Bones & soft tissues
• Inspect the bones for visible fractures (e.g. ribs & clavicles) or
lytic/sclerotic lesions (e.g. myeloma, metastases)
• Inspect the soft tissues for any abnormalities such as hematoma

61. Tubes, valves and pacemakers
We may see:
Nasogastric tubes
Central lines
ECG leads
Artificial heart valves
Pacemakers

65. Final Review areas
Lung apices
Retrocardiac region
Lung peripheries

66. Document your findings
Patient details (name, DOB and ID number)
Date and time chest x-ray was performed
Indication/clinical context
Document each finding using ABCDE format
Overall impression
Plan
Your name, grade, signature, registration
number and contact number

67. Take Home Message
• Patient details should always be checked before reading an x-ray
• Appropriate image quality is necessary for interpreting of an x- ray
• PA projection is standard projection
• It is important to know the clinical context before ordering an x-ray as
it will help in overall interpretation & reaching DD

68. References
• UpToDate
• Radipaedia.org
• Davidson’s Principles & Practice of Medicine
• Harrison’s Principle of Internal Medicine
• Washington Manual of Medical Therapeutics