Abnormal CXR

Question 1

Typical (lobar or segmental): MC type of pneumonia

Answer 1

• Pneumococcal pneumonia – Strep pneumoniae
• Infection contained within a single lobe or part of a lobe
  
  • Affected tissue is more opaque aka infiltrate
  • May contain air bronchograms
  • Silhouette sign: helps localize the lobe
  • Airspace dz, fluffy, cloudlike, indistinct borders

Question 2

Bacterial Pneumonia

Answer 2

• Typically lobar, single consolidation

Question 3

Bad Lobar Pneumonias: worse bacterial pathogens = bronchopneumoina

Answer 3

• Staph aureus …. Also gram negative bacteria (klebsiellae and pseudomonas)
  
  • Patchy airspace dz involving several segments of lung, exudate may fill bronchi so may not have air bronchograms
• How to dx:
  
  • Sputum gram stain
  • Blood cultures
  • PCR for respiratory viruses
  • Legionella urinary antigen

Question 4

Air Bronchogram

Answer 4

• normally you can’t see airways>> as they get more stuff on the outside (consolidation) you can see the air going through the airway

Question 5

Atypical Pneumonia: “walking”

Answer 5

• MC mycoplasma pneumoniae
• No focal consolidation like bacterial, more diffuse and patchy
• Fine, reticular interstitial pattern in lungs

Question 6

Atypical: PCP/PJP: always multi-lobar

Answer 6

• MC infection in pts with AIDS
• Fine, reticular interstitial pattern in lungs

Question 7

Tuberculosis

Answer 7

• Parenchymal lung disease with Cavitary lesion
• CXR of active TB:
  
  • Classic: focal infiltration of upper lobes (apical/posterior) or lower lobe (apical/superior)
  • Can be unilateral or bilateral
  • Cavitation may be present and inflammation/tissue destruction causing fibrosis
    
    • Caseous granulomas
  • Enlargement of hilar and mediastinal lymph nodes

Question 8

Pleural effusion

Answer 8

• fluid trapped between visceral and parietal pleura
  
  • Normally contains 5-20 mL of pleural fluid
    
    • The rate of formation may be increased due to
      
      • inc hydrostatic pressure- Left HF
      • dec colloid osmotic pressure- hypoproteinemia
      • inc capillary permeability- infection
    • The rate of resorption can decrease by:
      
      • Decreased absorption of fluid by lymphatics- tumor

Question 9

pleural effusion etiology

Answer 9

• Etiology: cbc, protein and LDH level inc (get serum sample), gram stain, cytology
  
  • Transudates: bilateral, low protein low LDH
    
    • CHF MCC
    • Cirrhosis
    • Nephrotic syndrome
  • Exudates: unilateral, inc protein, inc LDH
    
    • Malignancy and infection MCC
    • Contains frank pus = empyema
    • Rheumatic dz can cause bilateral or unilateral –older ppl

Question 10

free pleural effusion

Answer 10

• You can see a meniscal line with free pleural effusions
  
  • Will have blurred costophrenic angles most of the time; will be white
  • The fluid will move with gravity when a lateral decubitus is taken.
  • You may need a lateral view to see the small effusion in the posterior mediastinum

Question 11

loculated pleural effusion

Answer 11

• can mimic pneumonia/consolidation
  
  • When you get a lateral decubitus and the fluid does not move with gravity.
  • If fluid is in a position where it could not normally hold itself up – adhesions are holding it up

Question 12

CXR view for pleural effusion

Answer 12

• Lateral decubitus with affected side down
• A pleural effusion can cause an atelectatic lung where the two layers are separated by fluid so the lung decreases in size but remains its shape.

Question 13

Pneumothorax

Answer 13

Air trapped in pleural space

Question 14

pneumothorax cause

Answer 14

• Trauma/iatrogenic- through a communication in the chest wall
• Spontaneous/COPD- thorugh lung parenchyma across visceral pleura
  
  • Copd- blebs that burst

Question 15

pneumothorax CXR

Answer 15

• look at the lining of the pleura at the periphery – they will be separated
  
  • Absence of vessels outside the pleural line
  • If it is a small pneumothorax, look at the apices first- up near clavicle!
  • Which one?
    
    • Expiratory Lateral decubitus with affected side up because air rises!

Question 16

Tension pneumothorax

Answer 16

• “so much air outside that is pushes everything to other side of chest”
  
  • Positive pressure that displaces the mediastinal structures (shifts them) to the opposite side of the pneumothorax
  • Impair venous return and compromise cardiopulmonary function
  • Can cause cardiac arrest if venous return sucks so BP will drop
  • On CXR:
    
    • Trachea deviated
    • Flattening or inversion of diaphragm w/partial or complete collapse of lung
  • You need to decompress this immediately if large enough….
    
    • Mainstay of tx: chest tube if large enough; inserted at apices since air rises
    • Body can absorb the air if it is a small one.

Question 17

Hilar enlargement

Answer 17

• Hilar adenopathy: prominent hilar border that is lobulated or polycyclic in contour- GRAPES
  
  • Aortopulmonary window is not clear
  • Enlarged Lymph Nodes
    
    • Lymph nodes have a lobular grape-cluster appearance on PA film
    • Sarcoidosis most common cause: “bilateral hilar lymphadenopathy”
    • Unilateral:
      
      • Mets from bronchial CA
      • Malignant Lymphoma-neoplasmas
      • Infections - esp TB and Histoplasmosis

Question 18

Bronchogenic Tumors

Answer 18

• Usually presents as solitary nodule
• If metastatic dz to lungs: multiple nodules
• Four types:
  
  • Squamous cell carcinoma
    
    • Central growing, in bronchi
  • Adenocarcinoma
    
    • Bronchoalveolar cell carcinoma
    • Peripheral
  • Small cell: centrally
  • Large cell carcinoma

Question 19

Enlarged Pulmonary Arteries

Answer 19

• Pulmonary arteries have a branching pattern

Question 20

Discuss the characteristics that help distinguish benign from malignant solitary pulmonary nodules

Answer 20

• Calcified nodule:
  
  • The more calcium the more radiopaque that it is going to look
  • Most likely benign
• Shape:
  
  • Irregular = bad
  • Speculated border- malignancy
• Nodules/masses: more sharply marginated than airspace dz and produce clear demarcation btwn nodule and lung tissue
  
  • Nodule < 3 cm
  • Mass > 3 cm
    
    • Malignant mass: > 5 cm
    • Change in size over time =malignant

Question 21

Recognize the classic appearance of pulmonary metastases

Answer 21

• See more bilateral nodules – they can be large or small
• They can look like whatever they want no matter what type of cancer
  
  • No size restriction/ not uniform- would be all over a lot of the time

Question 22

Severe Emphysema / COPD

Answer 22

• COPD: lung disease characterized by persistent respiratory symptoms and airflow limitations that is due to airway or alveolar abnormalities (noxious particle exposure= cigarettes)
  
  • On CXR: hyperinflation, flattening of diaphragm, inc retrosternal air space
    
    • Long, narrow, vertical, hanging heart
    • Hyperlucency of lungs (dec markings)
• Emphysema is destruction of the alveoli à as they are destroyed there is a pocket of dead air
  
  • Bullae/bleb formation w/emphysema
• Radiolucent CXR – ribs may look bigger, heart may look smaller, flattened diaphragm
• More barrel chested on lateral view

Question 23

Pulmonary infarction (Hamptons Hump and Westermark sign)

Answer 23

• Pulmonary emboli
  
  • CXR findings:
    
    • Westermark Sign
      
      • Truncated pulmonary artery
      • Collapse of the distal vasculature creating the appearance of a sharp cut off on chest radiography.
      • You are going to see this more centrally
    • Hampton’s Hump
      
      • Wedge shaped pleural based consolidation (mimics pneumonia)
        
        • Will see a large obstruction further out into the lung
      • Caused by Pulmonary Infarction associated with PE
    • Pleural effusion
    • Elevated diaphragm
    • CXR is usually normal - a normal film does NOT rule out a PE!!!

Question 24

Interstitial Lung Disease, e.g. idiopathic pulmonary fibrosis

Answer 24

• Has discrete reticular, nodular, or reticulonodular patterns
  
  • Usually diffuse
  • No air bronchograms present
  • What causes ILD:
    
    • Pulmonary fibrosis
    • Drugs/ct dz, environmental
    • Sarcoidosis
    • Early edema from HF
• CT: “ground glass opacities” or “honeycombing” – starts in the periphery and have thick scarred vessels (scarring in the interstitium highlights vessels), more advanced can be seen more centrally
• CXR: Lacy, reticular pattern typically involving most lung fields but can be apical or basilar predominate

Question 25

Bullae

Answer 25

* Thin-walled Air-filled space * Contained within the lung * Walls may be formed by pleura, septa, or compressed lung tissue

Question 26

Recognize cardiomegaly. Describe the classic radiographic appearance of congestive heart failure.

Answer 26

* Measure the cardiac width and divide by the thoracic width à should be under 50% for a normal pt * Above 50% is cardiomegaly on a **PA film** * Heart is enlarged * “water bottle sign” * the fluid is backing up in CHF and causing the heart to be enlarged due to inc blood stasis due to poor pumping out or hypertrophy of the muscles * CHF: most common dz of hospitalized pts over 65 yo * Pulmonary interstitial edema- early CHF * Pulmonary alveolar edema- later CHF * Batwings/butterfly distribution, bilateral * Fluffy, indistinct airspace densities * May also show: * Pleural effuisons * Kelry B * Cardiomegaly * Goes towards head and stays centrally

Question 27

Describe the classic radiographic appearance of a pericardial effusion

Answer 27

* Pericardial effusion: * Water bottle shape or water bottle sign

Question 28

Recognize mediastinal masses and list the differential diagnosis of anterior mediastinal masses

Answer 28

* Calcified LN * Pulmonary mets - Cancer * Hamartomas: benign tumors of lung that contain fat and calcification on CT * Granulomas: infectious etiology – scars from prior TB or fungal dz * Casesous- TB * Benign * Wegener granulomatosis: granulomatosis with polyangiitis – solitary * Benign * BEST pulmonary nodule to have: * Small, smooth, stable in size with large dollop of calcium!

Question 29

Endotracheal tubes

Answer 29

* Want it to stop below the clavicles and above the carina * Mostly clear but have a radiopaque line so you can find it

Question 30

Central venous catheters

Answer 30

* Under the clavicle into the internal jugular * Want it to end as close to the SVC and right atrium as you can – don’t want it to go through the tricuspid * You can have a left sided one that goes in subclavian down to SVC

Question 31

Nasogastric tubes

Answer 31

* This should go below the diaphragm down esophagus * Requires CXR after you insert!!!