This document provides an overview of various imaging modalities used for chest imaging including plain chest radiographs, computed tomography, MRI, nuclear medicine scans, ultrasound, and pulmonary angiography. It describes the technical aspects and clinical applications of each modality. Key points covered include how plain chest radiographs remain diagnostic in 80% of cases and involve standard views like PA and lateral. Computed tomography is further described as the main investigation used to evaluate most abnormal chest radiograph findings and certain scenarios like pulmonary embolism. [END SUMMARY]

1. Chest Imaging
RADIOLOGY DEPARTMENT

2. IMAGING MODALITIES
1. Plain chest Radiograph
2. Fluoroscopy
3. Computerized tomography
4. Radionuclide lung scan
5. MRI
6. Ultrasound
7. Pulmonary angiography

3. Plain chest radiograph
• Diagnostic in 80% cases
• Standard views
1. Postero-anterior(P/A)
2. Lateral (right/left)
• Additional views
1. Oblique view(ribs)
2. Apical lordotic view
3. Expiration view
4. Decubitus view

4. Computed Tomography
• Numerous
protocols/techniques
depending on clinical
history
• Helical/spiral versus high
resolution
• Contrast
– Renal failure
– Allergy

5. Computed Tomography
• Role of CT
– Main further investigation
for most CXR abnormality
(eg nodule/mass) or to
exclude disease with
normal CXR
– Main investigation for
certain scenarios (PE,
dissection, trauma)

6. MRI
• Multiple planes
• No radiation
• Common Indication
– Pancoast tumour
– Brachial plexus
– Cardiac
– Vascular (aorta)
• Usually targeted
examination (unlike
CT)
Coronal

7. Nuclear Medicine
• Variety of tests: functional rather than
anatomic
• V/Q specific to chest imaging
• Others: bone scan, gallium, WBC etc.

8. Ultrasound
• Limited use in thorax (non cardiac) due to
air in lungs
• Assess pleural effusions
• Mainly used for procedures

9. Chest Radiographs
• PA (posterior to anterior) and Lateral (left)
– Minimizes magnification of heart (heart closest to film)
• Portable (nearly always AP)
– Supine or Erect
• Specialized Views
– Lordotic
– Lateral decubitus (for effusions, pneumothorax)

10. Lordotic View
Better assess apices without bone overlap

11. 1
1: Adequate penetration of
4
a the mediastinum-is the
a thoracic spine seen?
2: Has the patient taken a good
inspiratory effort? About 8-10
7
posterior thoracic ribs should be
seen through the lungs
3: Is there any rotation of the
chest? Assessed by checking
10 the upper thoracic spinous
process (oval) in relation to the
medial ends of the clavicles
(lines ‘a’) - this CXR is rotated to
left

14. Retro sternal space Retro cardiac space

15. Chest Radiograph: Approach and
Normal Anatomy
THERE IS NO ONE APPROACH: BE SYSTEMATIC
• Bone and Soft Tissue including abdomen
• Heart
• Mediastinum-aorta, trachea
• Hila
• Pulmonary Vasculature
• Lungs
• Pleura

16. Sequence For X Ray Reading
5 Ds
• Detect
• Describe
• Differential Diagnosis
• Discuss
• Diagnosis

17. CXR: Superimposition

18. CT Coronal Reconstruction
Right Brachiocephalic
Left Brachiocephalic Vein
Vein
Superior
Vena
Cava
Right
Atrium
Inferior Vena Cava

19. Heart Size • Normal is <50% on PA
upright radiograph

20. Increased Cardiac Size
Normal for comparison
Cardiomegaly (Big heart)

21. MRI of Aorta Aorta
PA view
Aortic arch
Descending
Aorta

22. Aorta CXR: Lateral View
Ascending Descending
Aorta Aorta

23. Case: Aorta can be enlarged
(aneurysm)

24. Pulmonary Artery
Left Lung
Coronal Image
PA
Lung “markings”
are
pulmonary arteries
and veins

25. • Spine Sign: Lungs
posteriorly should get
Scapula
darker as you go down
inspexp more inferiorly
Retrosternal
Airspace
Hilum
IVC
Pulmonary
Vessels

26. Case: (Look at the trachea)
Trachea is
Deviated by
large mass
(goiter)

27. Abnormal Cases
• Bone
• Cardiovascular
• Airspace Disease including Silhouette Sign
• Interstitial Disease and Pulmonary Edema
• Atelectasis
• Pulmonary Nodule
• Pleura and Diaphragm
• Mediastinal Mass

29. ACINAR PATTERN (CXR)
Radiology: Round or elliptical ill-defined 4-8mm opacities in lung
Microscopic: Portion of lung distal to terminal bronchial (respiratory bronchial,
alveolar duct, alveolar sac and alveoli) is the acinus
CXR close up of acinar pattern

30. ACINAR PATTERN (CT SCAN)
Round or elliptical ill-defined 4-8mm opacities in
lung
CT scan of right upper lobe
showing typical acinar pattern
(arrow)

31. AIR BRONCHOGRAM
Air containing bronchus peripheral to the hilum
surrounded by airless lung
CXR CT Scan
Air Bronchogram

32. NODULAR PATTERN
Collection of innumerable small, linear and nodular opacities
together producing a net with small superimposed nodules.
CT
CXR
Close up of nodular pattern

33. EMPHYSEMA:
Abnormally expanded air spaces distal to terminal
bronchiole with destruction of walls of involved air
spaces..
BULLA: Gas containing avascularity of lung measuring 1cm or more in
diameter, 1mm thickness
Bulla CT of bulla

34. Pneumonia (consolidation)
• Air bronchograms would confirm an alveolar process.
• The lung volume should not be lost (may even be
increased).
• Usually all radiographic abnormalities should disappear
after 6 weeks of appropriate antibiotic therapy.

35. Pneumonia RML

36. Right Upper Lobe Pneumonia

37. Left Lingular Pneumonia

38. Left Lower Lobe Pneumonia

39. Pneumonia RLL

40. Consolidation and follow-up X-rays
• Recommendations are, repeat film at 1, 3 and 7 days to check for
the development of complications.
• Resolution of the X-ray signs always lags behind the clinical
findings
• The X-ray should therefore be repeated 4 weeks later to check for
resolution.
• If there is persistent consolidation at this stage, further investigation
is necessary to exclude an obstructive lesion.

41. SIGNS OF COLLAPSE
DIRECT SIGNS:
• Displacement of fissures
• Loss of aeration
• Vascular & bronchial signs
INDIRECT SIGNS:
• Mediastinal & Hilar displacement
• Elevation of Hemidiphragm
• Compensatory hyperinflation

42. Collapse RUL

43. Collapse LUL

44. Indistinct Right
Heart Border

45. Right Middle Lobe Atelectasis

48. Left lower lobe collapse
• Further investigations?

49. Diagnosis: LLL Collapse
• Collapse secondary to central obstructing
tumour

50. Pleural Effusion

51. Small Pleural Effusion

52. Small Pleural Effusion
Normal:
Sharp Angles
Blunted posterior costophrenic sulcus

53. Pleural Effusion

55. Tension Pneumothorax

57. ptxinspexp
Inspiration Expiration

58. hugeptx
Tracheal Deviation
Collapsed Right Lung
What would you do with this patient?
Tension Pneumothorax: Requires chest tube

59. Causes of a pneumothorax
• Spontaneous
• Iatrogenic/trauma,
• Obstructive lung disease, e.g. asthma, COPD
• Infection, e.g. pneumonia, tuberculosis Cystic
fibrosis
• Connective Tissue Disorders, e.g. Marfan’s,
Ehlers-Danlos

60. Pneumomed

61. Diagnosis: Pneumomediastinum

63. Coin Lesion

64. Causes of single coin lesions
• Benign tumor, e.g. hamartoma
• Malignant tumor, e.g. bronchial carcinoma,
single secondary
• Infection, e.g. pneumonia, abscess,
tuberculosis, hydatid cyst
• Infarction
• Rheumatoid nodule

65. Solitary Pulmonary Nodule can be:
Malignant: Adenocarcinoma Benign: Densely calcified nodule

66. Cavitating lung lesion

67. Causes of cavitating lung lesions
• Abscess
• Neoplasm
• Cavitating pneumonia
• Cavitations in infarct
• Rheumatoid nodules (rare)

68. Left Ventricular Failure

69. CASE 1
1:What is your diagnosis
History: Young patient with
cough and night sweats
2: Give differential
diagnosis for upper lobe

70. Normal

72. Severe heart failure
• Severe pulmonary edema gives confluent
alveolar shadowing which spreads out from the
hilum giving a 'bat's wing' appearance.
• If this is the cause of generalized shadowing
then upper lobe blood diversion and Kerley B
lines should be present.
• In pulmonary edema hilum may appear
distended and the vessels close to the hilum
may be blurred.

73. Severe heart failure vs. non-
carcinogenic pulmonary edema
• In non-cardiogenic pulmonary edema the heart
size is likely to be normal and there will not
necessarily be sparing of the peripheries.

74. COPD

75. Bronchiectasis

76. Causes of Bronchiectasis
• Structural, e.g. Kartagener syndrome,
• obstruction (carcinoma, foreign body)
• Infection, e.g. childhood pertussis or
measles, tuberculosis, pneumonia
• Immune, e.g. hypogammaglobulinaemia,
allergic bronchopulmonary aspergillosis
• Metabolic, e.g. cystic fibrosis
• Idiopathic to stasis

77. Unilateral Hilar enlargement

78. Unilateral Hilar Enlargement
• Causes of hilar lymphadenopothy
– Neoplastic, e.g. spread from bronchial
carcinoma, primary lymphoma
– Infective, e.g. tuberculosis
– Sarcoidosis (rarely unilateral)
• Causes of hilar vascular enlargement
– Pulmonary artery aneurysm
– Poststenotic dilatation of the pulmonary artery

79. Bilateral Hilar Enlargement

80. Bilateral Hilar Enlargement
• Causes of bilateral hilar lymphadenopathy
– Sarcoid
– Tumors, e.g. lymphoma, bronchial carcinoma, metastatic tumors
– Infection, e.g. tuberculosis, recurrent chest infections, AIDS
– Berylliosis
• Causes of pulmonary hypertension
– Obstructive lung disease, e.g. asthma, COPD
– Left heart disease, e.g. mitral stenosis, left ventricular failure
– Left to right shunts, e.g. ASD, VSD
– Recurrent pulmonary emboli
– Primary pulmonary hypertension

81. Paratracheal and Hilar Lymphadenopathy: ?Diagnosis

82. NORMAL

83. Sarcoidosis

84. benignthymoma

85. Lateral shows mass is anterior
NORMAL

86. Computed Tomography
Thymoma:
Do you know of any
associated
clinical syndrome?

87. Presenting CXR

89. MRI
Computed Tomography

90. pulmedema
SOB

91. Same Patient

92. baseline
Same Patient: Baseline

93. Rul collapse
RUL Collapse

94. Lul consolidation

95. Diagnosis: LUL Consolidation

96. Paratracheal ln

97. Right Paratracheal Lymphadenopathy

98. RML Consolidation
Rml consolidation

99. 50 y.o female with progressive SOB.
What can you do to improve SOB?

100. Volume loss with atelectasis
Mass effect with large effusion

101. baseline
Mastectomy

102. Hiatus hernia
hh

103. Rt. Paratracheal
Lymphadenopathy
(Lymphoma)
After Therapy
Where is the Lymphadenopathy?

104. Nipple Shadow