1. Radiologic Examination of the Chest
Chapter 7
 Radiologic Examination of the Chest

2. Fundamentals of Radiography

3. Standard Positions and Techniques of Chest Radiography
Posteroanterior (PA) radiograph
Anteroposterior (AP) radiograph
Lateral radiograph
Lateral decubitus radiograph

4. Posteroanterior Radiograph
The standard PA chest radiograph is obtained by having the patient stand (or sit) in the upright position.
The anterior aspect of the patient’s chest is pressed against a film cassette holder.

5. Figure 7-1. Standard PA chest radiograph with the patient’s lungs in full inspiration.

6. Figure 7-2. A PA chest radiograph of the same patient shown in Figure 7-1 during expiration.

7. Figure 7-3. Compared with the PA chest radiograph, the heart is significantly magnified in the AP chest radiograph. In the PA radiograph the ratio of the width of the heart to the thorax is normally less than 1 : 2.

8. Anteroposterior Radiograph
The supine AP radiograph may be taken in patients who are debilitated, immobilized, or too young to tolerate the PA procedure.
The AP radiograph is usually taken with a portable x-ray machine at the patient’s bedside.
The film is placed behind the patient’s back, with the x-ray machine positioned in front of the patient approximately 48 inches from the film.

9. Figure 7-4. AP chest radiograph. The diaphragms are elevated, the lower lung lobes appear hazy, the ratio of the width of the heart to the thorax is greater than 2 : 1, and extraneous lines are apparent on the patient’s left side.

10. Lateral Radiograph
The lateral radiograph is obtained to complement the PA radiograph. It is taken with the side of the patient’s chest compressed against the cassette.
The patient’s arms are raised, with the forearms resting on the head.

11. Figure 7-5. Lateral radiograph.
Figure 7-5. Lateral radiograph.

12. Lateral Decubitus Radiograph
The lateral decubitus radiograph is obtained by having the patient lie on the left or right side rather than standing or sitting in the upright position.
The naming of the decubitus radiograph is determined by the side on which the patient lies.
Thus a right lateral decubitus radiograph means that the patient’s right side is down.

13. Figure 7-6. Subpulmonic pleural effusion. Right lateral decubitus view
Figure 7-6. Subpulmonic pleural effusion. Right lateral decubitus view. Subdiaphragmatic fluid has run up the lateral chest wall, producing a band of soft tissue density. The medial curvilinear shadow (arrows) indicates fluid in the lips of the major fissure.

14. Inspecting the Chest Radiograph

15. Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea); 2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows; 12, gastric air bubble; 13, clavicle; 14, rib.

16. Figure 7-8. Normal lateral chest radiograph. 1, Manubrium; 2, sternum; 3, cardiac shadow; 4, retrosternal air space in the lung; 5, trachea; 6, bronchus, on end; 7, aortic arch (ascending and descending); 8, scapulae; 9, vertebral column; 10, diaphragm; 11, breast shadow.

17. Table 7-1 Common Radiologic Terms
Air cyst
Bleb
Bulla
Bronchogram
Cavity
Consolidation
Homogeneous density
Honeycombing
Infiltrate

18. Table 7-1 Common Radiologic Terms (Cont’d)
Interstitial density
Lesion
Opacity
Pleural density
Pulmonary mass
Pulmonary nodule
Radiodensity
Radiolucency
Translucent

19. Selected Examples of Common Radiologic Terms

20. Lung abscess with cavities
Cavity
Lung abscess with cavities
Radiograph of cavity
Reactivation tuberculosis (TB) with a large cavitary lesion containing an air-fluid level in the right lower lobe.
Lung abscess with air-fluid cavity.

21. Cavity (Cont’d) Lung with TB cavities Radiograph of cavity
Tuberculosis.
Cavitary reactivation TB showing a left upper lobe cavity and localized pleural thickening (arrows).

22. Consolidation or Opacity (Caused by Right Lung Pneumonia)

23. Bronchogram
Air bronchogram.

24. Bronchogram Shown in Chest CT Scan

25. Honeycombing Shown in Interstitial Pulmonary Fibrosis
Honeycomb cysts.

26. Infiltrate Shown in Patient with ARDS—General Term
Cross-sectional view of alveoli in adult respiratory distress syndrome.
Chest x-ray film of a patient with moderately severe ARDS.

27. Right-sided pleural effusion.
Pleural Density
Right-sided pleural effusion.

28. Pulmonary Mass
Cancer of the lung.
Cancer of the lung.

29. Radiodensity (Caused by a Right Lung Pneumonia)

30. Translucency or Radiolucency (Caused by a Right Pneumothorax)

31. Translucency or Radiolucency Caused by Chronic Emphysema
Centrilobular emphysema.
Chest x-ray study of a patient with emphysema.

32. Technical Quality of the Radiograph
Exposure quality
Level of inspiration

33. First Technical Quality
Was the patient in the correct position?
Check the medial ends of the clavicles to the vertebral column.
Even a small degree of patient rotation can create a false image.
Can erroneously suggest tracheal deviation, cardiac displacement, or cardiac enlargement

34. Second Exposure Quality
Normal exposure is verified by determining whether the spinal processes of the vertebrae are visible to the fifth or sixth thoracic level.
Compare the relative densities of the heart and lungs.
Overexposure: heart and lungs more radiolucent
Underexposure: heart and lungs more dense or whiter

35. Third Level of Inspiration When Radiograph Was Taken
At full inspiration, the diaphragmatic domes should be at the level of the ninth to eleventh ribs posteriorly.
At expiration, the lungs appear denser, the diaphragm is elevated, and the heart appears wider and enlarged.

36. Sequence of Examination
Mediastinum
Trachea
Heart
Hilar region
Lung parenchyma (tissue)

37. Figure 7-7. Normal PA chest radiograph
Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea); 2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows; 12, gastric air bubble; 13, clavicle; 14, rib.

38. Sequence of Examination (Cont’d)
Pleura
Diaphragm
Gastric air bubble
Bony thorax
Extrathoracic soft tissues

39. Figure 7-7. Normal PA chest radiograph
Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea); 2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows; 12, gastric air bubble; 13, clavicle; 14, rib.

40. Structure Abnormal Position Causes
Table 7-2 Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph
Structure
Mediastinum
Trachea
Carina
Heart
Major vessels
Abnormal Position
Leftward shift
Causes
Pulled left by upper lobe tuberculosis, atelectasis, or fibrosis
Pushed left by right upper lobe emphysematous bulla, fluid, gas, or tumor

41. Structure Abnormal Position Causes
Table 7-2 Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d)
Structure
Left diaphragm
Abnormal Position
Upward shift
Causes
Pulled up by left lower lobe atelectasis or fibrosis
Pushed up by distended gastric air bubble

42. Structure Abnormal Position Causes
Table 7-2 Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d)
Structure
Horizontal fissure
Right lung
Right hilum
Abnormal Position
Downward shift
Causes
Pulled down by right middle lobe or right lower lobe atelectasis
Pushed down by right upper lobe neoplasm

43. Structure Abnormal Position Causes
Table 7-2 Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d)
Structure
Left lung
Abnormal Position
Rightward shift
Causes
Pulled right by right lung collapse, atelectasis, or fibrosis
Pushed right by left-sided tension pneumothorax or hemothorax

44. Other Radiologic Techniques
Computed tomography (CT)
CT scan
Position emission tomography (PET)
PET scan
Magnetic resonance imaging
Pulmonary angiography
Ventilation-perfusion scan
Fluoroscopy
Bronchography

45. Computed Tomography
Computed tomography (CT) scanning provides a series of cross-sectional (transverse) pictures of the structures within the body at numerous levels. 45

46. Figure 7-9. The principle of spiral computed tomography
Figure The principle of spiral computed tomography. The patient moves into the scanner with the x-ray tube continuously rotating and the detectors acquiring information. The rapidity of data acquisition allows a complete examination of the throax to be performed in a single breath hold.

47. Normal CT Scan Lung Window
Figure Overview of normal lung window CT scan. The apex appears in the two views in the upper right corner of this figure; the diaphragm at the base of the lungs appears in the lower right hand view.

48. Example of Several Normal CT Scan Lung Window Slices

49. Normal CT Scan Lung WindowB
Figure Close-up of a normal lung window CT scan. A, The portion of the chest the CT scan is taken.
Figure B, The actual cross-sectional slice, or axial view of the chest.

50. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

51. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

52. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

53. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

54. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

55. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

56. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

57. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

58. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

59. Normal CT Scan Lung Window (Cont’d)
Figure 7-10, cont.

60. Example of Several Normal CT Scan Mediastinal Windows

61. Figure Close-up of a normal lung window computed tomography (CT) scan. A, The portion of the chest undergoing CT scanning. B, The actual cross-sectional slice, or axial view of the chest. Note the carina and both mainstem bronchi (arrow) 61

62. Normal CT Mediastinal Window
Figure Close-up of normal CT mediastinal window. A, The portion of the chest the CT scan is taken. B, The actual cross-sectional slice, or axial view of the chest. Note that the lungs are overexposed and appear mostly black. The bone and mediastinal organs appear mostly white.

63. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

64. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

65. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

66. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

67. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

68. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

69. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

70. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

71. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

72. Normal CT Mediastinal Window (Cont’d)
Figure 7-12, cont.

73. Positron Emission Tomography (PET) Scan
The PET scan shows both the anatomic structures and the metabolic activity of the tissues and organs scanned.

74. A B
Figure Chest radiograph identifying two suspicious findings: in the right upper lobe (A) and in the left lower lobe (B), just behind the heart (white arrows).

75. CT scan, upper right lobe
Chest radiograph
CT scan, left lower lobe
Figure Same chest radiograph as shown in Figure Note that the CT scan also identifies the suspicious nodules and their precise location.

76. Coronal View
Figure PET scan: coronal views. The last three views show a hot spot in the left lower lobe.

77. Figure 7-16. PET scan: sagittal views
Figure PET scan: sagittal views. The encircled images show a hot spot in the lower left lobe.

78. Axial View
Figure PET scan: axial view. A “hot spot” is further confirmed in left lower lobe.

79. Axial View No hot spot seen
Figure PET scan: axial view. This image confirms that the small nodule identified in the upper right lobe in the chest radiograph and CT scan is benign (i.e., no hot spot is evident).

80. Positron Emission Tomography and Computed Tomography Scan (PET/CT scan)
The PET scan and the CT scan merge together at the same time.
The PET/CT scan provides an image far superior to that afforded by either technology independently.
The CT scan provides the anatomic details; the PET scan provides the metabolic activity of the tumor or mass.

81. CT Scan CT/PET Fusion PET Scan
Axial View
Coronal View
Figure CT/PET scan (center). CT scan, CT/PET fusion, and PET scan, are all showing the same malignant nodule in right upper lobe (white arrow). Note: CT/PET fusion is normally presented in color (e.g., red, blue, yellow).

82. Magnetic Resonance Imaging (MRI)
MRI uses magnetic resonance as its source of energy to take cross-sectional (transverse, sagittal, or coronal) images of the body.

83. Figure Anatomy of mediastinum on magnetic resonance imaging (MRI) scan. A, Ao A, Aortic arch; Es, esophagus; LBCV, left brachiocephalic vein; RBCV, right brachiocephalic vein; T, trachea. B, Az V, Azygos vein; D Ao, descending aorta; Es, esophagus; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle. (From Armstrong P, Wilson AG, Dee P: Imaging of diseases of the chest, St Louis, 1990, Mosby.)

84. Pulmonary Angiography
Pulmonary angiography is useful in identifying pulmonary emboli or arteriovenous malformation.
It involves the injection of a radiopaque contrast medium through a catheter that has been passed through the right side of the heart and into the pulmonary artery.

85. Figure Abnormal pulmonary angiogram. Radiopaque material injected into the blood is prevented from flowing into the left lung past the pulmonary embolism (arrow). No vascular structures are seen distal to the obstruction.

86. Ventilation-Perfusion Scan
A ventilation-perfusion scan is useful in determining the presence of pulmonary embolism.
The perfusion scan is obtained by injecting small particles of albumin, called macroaggregates.
Tagged with a radioactive material such as iodine- 131 or technetium-99m

87. Figure Fat embolism in a patient with dyspnea and hypoxemia after a recent orthopedic procedure. Perfusion (P) and ventilation (V) radionuclide scans show multiple peripheral subsegmental perfusion defects suggestive of fat embolism. (From Hansell DM, Armstrong P, Lynch DA, McAdams HP: Imaging of diseases of the chest, ed 4, Philadelphia, 2005, Elsevier.)

88. Fluoroscopy
Fluoroscopy is a technique by which x-ray motion pictures of the chest are taken.
Fluoroscopy subjects the patient to a larger dose of x-rays than does standard radiography.
Therefore it is used only in selected cases, as in the assessment of abnormal diaphragmatic movement.

89. Bronchography
Bronchography entails the instillation of a radiopaque material into the lumen of the tracheobronchial tree.
A chest radiograph is then taken, providing a film called a bronchogram.
The contrast material provides a clear outline of the trachea, carina, right and left main stem bronchi, and segmental bronchi.

90. Figure Bronchogram obtained using contrast medium in a patient with a history of bronchiectasis. Arrows indicate the carina and the bronchi leading to the posterior basilar segment of the left lower lobe.