1. Chest Imaging: Introduction
2014/2015
Hassan Al-Balas, MD
Edited by raghad jber .

2. Dr. موفق الحيص discuss with us all the images so I wrote all the notes that mentioned by him .
Please forgave me for any mistake .
And focus on the Qs that mention , it may come in our exam .
good luck :)

3. Outline Imaging modalities in chest evaluation. Chest pathology:
Lung parenchymal pathology
Mediastinal pathology.
Pleural pathology.
Specific Entities:
Pulmonary edema.
TB.
Airway disease.
Pneumothorax.

4. Imaging Modalities Chest X-Ray: PA and Lateral views: AP view:
PA view is obtained with patient in standing position and in full inspiration.
Lateral chest view is obtained with left side against the cassette to minimize cardiac magnification.
AP view:
Portable view is obtained with patient in supine or sitting patient.
Because of decreased X Ray source patient distance, there is significant magnification factor.
Usually obtained in sick patients in ICU and is less useful than PA view.

7. Imaging modalities Evaluate PA CXR for adequate and proper technique:
Penetration:
Faint visualization of the thoracic disc spaces behind the cardiac shadow.
Rotation:
Thoracic spine process is midway between medial ends of the clavicles.
Inspiration:
Adequate inspiratory film should show the dome of the diaphragm below the 10th rib posteriorly.

9. Imaging Modalities Chest X-Ray: Special views: Decubitus view:
Obtained with patient on his lateral side.
Is used to evaluate:
Size and possible loculation of the pleural effusion.
Small pneumothorax in patient an upright CXR is not possible.
Air trapping.
Lordiotic view:
Obtained with patient leaning backward.
Useful for evaluation of lung apices.

12. Imaging Modalities CT Scan: MRI: Nuclear Ventilation/ perfusion scans:
Non-contrast CT:
Is used to evaluate lung parenchyma, e.g. metastasis.
Contrast enhanced CT:
Essential for evaluation of mediastinal and hilar structures.
High Resolution CT:
Non contrast thin section images.
For evaluation of interstitial lung disease.
MRI:
Very limited value for chest evaluation.
Nuclear Ventilation/ perfusion scans:
To evaluate for pulmonary embolism.
Angiography:
Evaluate vascular pathology.

13. Normal lung
Individual alveoli are too small to resolve, but together they appear radiolucent.

14. Lung parenchymal pathology
Air space disease.
Interstitial lung disease.
Focal lung masses/ Nodules.

15. Lung tumors Primary .. Usually solitary . Scc Nscc
Adenocarcinoma (not associated with smoking)
Large cc
Sequamous (strong associated with somking , peripheral lesion , present as a nodule )
Metastasis
multiple , peripheral and well defined .

16. Air-space Disease
Filling of alveoli by: water, blood, pus, proteinaceous fluid or cells
- Ground glass
- Consolidation

17. Lung pathology: Airspace disease
Also known alveolar lung disease.
Features of Airspace disease:
Air bronchogram.
Respects lobar anatomy.
Ill-defined borders except at fissures.
Airspace disease could be:
Partial: Ground glass opacity.
Complete: Consolidation.

18. Air bronchogram refers to the phenomenon of air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli (grey/white). It is almost always caused by a pathologic airspace/alveolar process .
Normally can’t see air bronchogram because both alveoli and bronchi contain air .
Air bronchogram is a sign of infection.
Most common cause of air bronchogram :
CHF
Pneumonia
Lymphoma or atypical chest infection

19. Chest CT scan , lung window
Right lung consolidation , why ?
Because of air bronchogram .
Chest CT scan , lung window ,
Pathology (bilateral patchy consolidation with air bronchogram , indicate bronchopneumonia )
** in the exam it’s enough to say it’s infection most likely pneumonia .

20. Criteria to determind the area of consolidation :
Cardiothoracic ratio
silhouette sign refers to the loss of normal borders between thoracic structures , ex : if there is a consolidation in right middle lobe , the right border of RT atrium will obliterate . Also if there is a consolidation in the left lower lobe and obliteration of LF diaphrgam it’s a positive sign .
Air bronchogram .

21. Dr. said this Q will be in the exam but the site of consolidation may differ .
Q What is the pathology ?
Consolidation seen in pneumonia .
Q Where is the site ?
Right upper lobe .

22. Alveolar Lung Disease(ALD)
Causes of ALD:
Acute:
Pulmonary edema.
Pneumonias.
Pulmonary hemorrhage.
Chronic:
Broncho-alveolar carcinoma.
Lymphoma.
Alveolar proteinosis.

23. Interstitial Disease Diffuse and bilateral.
May have regional distribution.

24. Interstitial lung disease
Normal interstitium is not seen on CXR unless is diseased.
ILD on Xray :
Loss of lung volume .
Thickening of interstitial septa .
Ground glass appearance .
Four patterns of interstitial lung disease:
Linear.
Reticular.
Nodular
Reticulo-nodular

25. Cont. End stage pattern of interstitial lung disease = honeycombing.
Small sub-pleural cystic changes of the lung parenchyma.
Most prominent in the lower lung lobes.
Nonspecific finding represent end stage ILD secondary to several underlying pathology.

27. Interstitial lung disease
Linear pattern:
Thickened interlobular septa.
Called kerley A and B lines:
kerley A lines:
Long lines(2-6cm).
Centrally located radiating from hila.
More common in upper and mid lung fields.
Kerley B lines:
Short (1-2cm).
Peripheral sub-pleural location.
More common in lower lung fields.
Common etiology:
Pulmonary edema: most common etiology.
CHD
Interstitial pneumonia-viral or mycoplasma.
Lymphangitis carcinomatosis.

28. A line
Radiated from the hilum
B line
Peripherally
Chest XRY , bilateral interstitial lung disease with A , B lines

29. The patient present with hypoxia ,chest tightness . Diagnosed with CHD .
This chest xray , the lung is congested bilaterally , cardiomegaly , we can see B lines (blue arrow ) {not important to know the name of the lines if it’s A or B but it’s important to know it’s septal thickening , and know the causes } .

30. Interstitial lung disease
Reticular pattern:
Result from summation of irregular linear opacities.
Usually associated with low lung volumes.
Classic example:
Idiopathic pulmonary fibrosis.
Asbestosis.
Scleroderma.

31. On the right , CXRY , right lung .
On the Lf , chest CT , lung window , Rt lung with reticulonodular pattern interstitial lung disease .

32. Will come in the exam .
CXRY , bilateral reticulonodular pattern in the lower lobes , this is interstitial pulmonary fibrosis .

33. Interstitial lung disease
Nodular pattern:
Numerous small nodules (1mm-10mm in diameter).
Miliary pattern: small nodules 1-2mm in diameter.
Classic examples:
Miliary TB.
Sarcoidosis.
Silicosis.
Metastasis from thyroid, kidney, …

34. CXRY , bilateral miliary shadowing , the causes (sarcoidosis and TB ) .

35. On the right : CXRY , reticular interstitial disease , the next of investigation is chest CT .
On LF : chest ct lung window ,interstitial pulmonary fibrosis .

36. chest ct lung window ,interstitial pulmonary fibrosis , honeycomb appearance .

37. Focal lung pathology Characterization of focal lung pathology: Size:
Nodule(<3cm) vs. mass(>3cm).
Number:
Single vs. multiple.
Cavitation:
Presence and thickness of the cavity.
Calcifications:
Presence and pattern of calcifications.
Margins:
Rounded vs speculated.

38. Focal lung pathology Bronchogenic carcinoma: Adenocarcinoma:
Most common.
Peripherally located.
Broncho-alveolar carcinoma is a subtype.
Squamous cell carcinoma:
Second most common type.
Strong smoking association.
Centrally located.
Most likely to cavitate.
Large cell carcinoma:
Rare type, peripherally located tumor.
Small cell carcinoma:
Very poor prognosis.

39. CXRY , rt side lung nodule , calcified .
Chest CT , lung window ,
rt side lung nodule , calcified .
Most likely calcified granuloma .

40. CXRY , on the left side calcified nodule popcorn
appearance mostly Hamartoma

41. CXRY , left side upper lobe obacity
Chest ct lung window , left side upper lobe infiltrating mass , it’s primary lung cancer .

42. CXRY , in the right side opacity in the lower zone .
Chest CT , lung window , in the right side in the lower lobe cavitation .
1st , 2nd ribs … upper zone
3rd , 4th ribs …. Middle zone
5th , 6th … lower zone

43. CXRY , multiple lung nodules bilateral .
Chest CT , lung window , multiple lung nodules bilateral .
Most likely mets .

44. Pleural/ chest wall pathology
Pleural effusion:
Accumulation of transudate or exudate fluid in the pleural cavity.
Signs of pleural effusion:
Blunted costo-phrenic angle.
Meniscus sign.
Opacification of hemithorax.
Loculated effusion:
Usually seen in empyema or malignant effusion.
Failure of layering on decubitus film.
CT may show split pleural sign.

45. Normal R costophrenic angle Blunted L costophrenic angle
When cc of fluid accumulate in pleural space, the usually acute costo-phrenic angle becomes blunted

46. Meniscus Sign
Pleural fluid tends to rise higher along its edge producing a meniscus shape medially and laterally
Usually only lateral meniscus can be seen
The meniscus is a good indicator of the presence of a pleural effusion

48. CXRY , LT side of the lung
Total opacification ,
Maybe due to pleural effusion or lf side pneumonectomy , OR lung collapse .
To differentiate by US or CT SCAN .

49. CXRY , lateral decubitus position , patient laying on the rt side , so it’s rt lateral decubitus , RT side pleural effusion .

50. CXRY , RT side opacity in the lower and middle lobe , with multicavitation bilaterally .
It’s a pleural effusion on RT side
Horizontal fissure

52. Chest CT , lung window , extrapulmonary empyema
Pul. trunk
Descending aorta
Ascending

53. Opacified hemithorax DDX: Total lung collapse/ atelectasis.
Entire lung consolidation.
Large pleural effusion.
Post pneumonectomy.

54. Opacified hemithorax
In atelectasis, there is s shift toward the side of the opacification.
In pleural effusion, there is a shift away from the side of the opacification.
In pneumonia, there is no shift.
In pneumonectomy, the 5th rib is usually absent.

55. I think it’s collapse but not sure

56. I think it’s lf side pleural effusion

57. CXRY , LF side total lung consolidation , we can see air bronchogram .

58. Mediastinal Pathology
Mediastinal masses can be differentiated from lung parenchymal lesions by their smooth contour since they are covered by parietal pleura.
The mediastinum is divided anatomically into four compartments:
Superior.
Anterior.
Middle.
Posterior.

60. Mediastinal Pathology
Superior mediastinum:
Located between the thoracic inlet and a line connecting sterno-manubrial joint with T4 body.
DDX of superior mediastinal mass:
Lesion extending from the neck e.g. thyroid mass, cystic hygroma.
Lymphadenopathy.
Vascular abnormalities e.g. aneurysm.

61. CXRY , superior mediastinal mass , most likely thyroid mass .

62. Chest CT , mediastinal window with contrast , retrosternal goiter

63. Mediastinal Pathology
Anterior mediastinum:
Also known pre-vascular space.
Located between the stenum anteriorly and pericardium and great vessels posteriorly.
It contains lymph nodes and thymus.
DDX of anterior mediastinal mass are:
4 T’s
Thymoma
Teratoma
Thyroid
Terrible lymphoma.

64. Lymphadenopathy
CXRY , mediastinal soft tissue mass most likely from anterior or middle mediastinum , order chest CT for the patient , DX hyperatrophy lymphadenopathy .

65. Thymoma
CXRY , rt side opacity from anterior mediastinal thymoma .
Lateral CXRY , anterior mediastinal mass mostly due to thymoma .

66. Chest CT , media stinal window , anterior mediastinal mass
Chest CT , media stinal window , anterior mediastinal mass .cause one of the 4 Ts . Mostly here thymoma .

67. Mediastinal Pathology
Middle mediastinum:
Also known vascular space.
Located between the anterior and posterior mediastnum.
Contains the heart, pericardium, trachea and major arteries and veins.
DDX of middle mediastinal masses:
3 A’s.
Vascular/ aneurysm.
Lymphadenopathy.
Congenital lesions.

68. Lateral XRY , mass in Posterior mediastinum

69. Mediastinal Pathology
Posterior mediastinum:
Post vascular space.
Located posterior to the heart and anterior to the spine.
Content: descending aorta, esophagus, sympathetic chains and lymph nodes.
DDX of posterior mediastinal masses:
Neurogenic tumors-most common.
Others e.g. lymphoma, descending aortic aneurysm, esophageal varices, hiatal hernia,..

70. Chest CT , mediastinal window , RT side posterior mediastinal mass (due to pregnant sign , smooth outline pouching the lung not infiltrate with lung tissue ) .

71. Calcification in the coronary artery

73. Pulmonary edema/ CHF Usually results from congestive heart failure.
It may/ may not be associated with cardiomegaly.
Other causes of pulmonary edema includes:
Renal failure.
fluid overload.
Two types of pulmonary edema:
Interstitial pulmonary edema.
Alveolar pulmonary edema.

74. Congestive Heart Failure Four Signs of Pulmonary interstitial edema
Thickening of the interlobular septa:
Kerley B lines
Peribronchial cuffing:
Wall is normally hairline thin
Thickening of the fissures
Pleural effusions

75. Peribronchial Cuffing
Bronchial wall is usually not visible
Interstitial fluid accumulates around bronchi
Causes thickening of bronchial wall
When seen on end, looks like little “doughnuts”
Meaningful when seen distal to hilar area

77. Fluid in The Fissures Fluid collects in the subpleural space
Between visceral pleura and lung parenchyma
Normal fissure is thickness of a sharpened pencil line
Fluid may collect in any fissure
Major, minor, accessory fissures, azygous fissure

78. Fluid in the minor fissure

80. Congestive Heart Failure Pulmonary alveolar edema
Fluffy, indistinct patchy densities
Outer third of lung frequently spared
Bat-wing or butterfly configuration
Lower lung zones more affected than upper

81. Minor fissure
Pulmonary Edema
154 slides 81

82. Cardiomegaly Normal cardiothoracic ratio is less than 50%.
Several entities may cause apparent cardiomegaly:
Portable AP view.
Obesity.
Ascites.
Pectus excavatum.

83. Cardio-thoracic Ratio
<50%

84. Tuberculosis Two forms of TB: Primary: Reactivation TB:
Usually is a disease of childhood.
Usually resolves without trace or may leave Ghon complex.
Usually mild consolidation associated with unilateral hilar and mediastinal lymphadenopathy.
Reactivation TB:
Ill-defined opacity associated with cavitation and satellite lesions.
Affects mostly posterior segment of the upper lobes or superior segment of the lower lobes.

87. TB

88. miliary tb shadow
Other cause of this appearance :
Sarcoidosis
Metastasis
Dr. said this will be a question in the exam .

89. Airway Disease Includes: COPD. Bronchiactasis. Emphysema.
Chronic bronchitis.
Bronchiactasis.
Cystic vs. cylindrical.
Focal vs. diffuse

90. Bullous Emphysema Increase in the volume of the lung. Sign on CXRY :
Increase air in the lung , more hyperlucency .
Flat diaphragm
On lateral Xray ; retrosternal space >4.5cm
Decrease in the bronchovascular marking bilateral .
Heart size is small .

91. Bullous Emphysema Enlarged Retrosternal Air Space Flattened Diaphragms
154 slides 91

92. Heart size small

93. CXRY ,
Findings :
Heart small
Multiple cavlitating lesions due to dilated cyst structures .
bronchiectasis

94. Chest CT , lung window , dilated bilateral bronchi it’s bronchiectasis

95. Pneumothorax
There are two layers of pleura- parietal and visceral-the pleural space between them .
Normally there is no air in the pleural space.
The visceral pleura is inseparable from the lung parenchyma and moves with the lung.
When air enters the pleural space, the parietal and visceral pleura separate making the visceral pleura visible
The thin white line of the visceral pleura is called the visceral pleural white line
You must see the visceral pleural white line to make diagnosis of pneumothorax

96. A pneumothorax will be visible as a thin white line - the visceral pleural white line

97. Skin fold vs. Pneumothorax
A fold of the patient’s skin may become trapped between the patient and cassette
Skin folds are common
Especially in patient’s who have lost a great deal of weight
This skin fold can mimic a pneumothorax

98. This is an edge
Dense
Lucent
Skin Fold
The key difference is that a skin fold is an edge consisting of a density (light) and then a lucency (dark)

99. Pneumothorax
This is a line
Lucent
Dense
Lucent
Whereas the visceral pleural line is a thin white line with a lucency (darker) on both sides of it

100. Skin Fold
Pneumothorax

101. Types of Pneumothoraces
Two major types of pneumothorax
Simple:
In a simple pneumothorax, there is no shift of the heart or mediastinal structures (trachea).
Air in left hemithorax balances the air in the right hemithorax.
Tension:
Progressive loss of air into pleural space causing a shift of the heart and mediastinal structures away from side of pneumothorax
Opposite lung is compressed
Respiratory function severely compromised

102. Baced on the pathophysiology , pneumothorax divided into :
Open ; stab wound .
Close ; RTA with non-penetrating injury .
Tension ; emergent condition .
tension treated by chest tube .

103. Tension pneumothorax

104. Addional note dr. said it will be in the exam :
Image for chest CT with contrast , and filling defect in pul. Trunk .
Dx .. PE
Cause ? DVT

105. The end