chest x rays Flashcards
basics
- CR, radiograph, film
- quick, inexpensive, non-invasive
- mirror of health or disease (identify many abnormalities/diseases; provides info about adjacent structures)
- doesn’t provide info about blood flow, ventilation, perfusion, etc.. other studies used
things to check
- x-ray is of your pt
- what view was taken (AP, PA, lateral)
- taken on inspiration?? if so, should be able to count the 10 posterior ribs
major difference from other x-rays
- chest films traditionally taken from posterior to anterior view
- different shades of gray of structures is related to tissues attenuation of x-ray beam
decreased to increased radiodensity:
- air
- fat
- water
- bone
- metal
CXR
- silhouette sign used to locate lesions in specific lobes of the lung
- no border between tissues of 2 similar densities
ex: if water density process like pneumonia is in a lobe near the heart, the border between that lobe and heart will disappear
commonly obliterated borders & associated lobes
Loss of border of superior mediastinum= lesion in upper lobes
Loss of border of R heart=lesion at R middle lobe
Loss of border of R hemi-diaphragm=lesion at R lower lobe
Loss of border of L hemi-diaphragm=lesion at L lower lobe
loss of border of superior mediastinum
=lesion in upper lobes
Loss of border of R heart
=lesion at R middle lobe
Loss of border of R hemi-diaphragm
lesion at R lower lobe
Loss of border of L hemi-diaphragm
lesion at L lower lobe
cardiothoracic ratio
- estimate of the size of the heart
- adults: widest width should be less that half the width of the chest at the level of the diaphragm
enlarged heart due to:
- cardiomyopathy
- CHF
- incompetent valves
heart appears enlarged if:
- AP view
- image made at expiration not inspiration
- diaphragm is superiorly displaced due to pregnancy, abdominal distention, or pericardial effusion is present & surrounding fluid enlarge entire cardiac image
mediastinum
=space between lungs; bound by sternum and spine
-contains heart, vessels, trachea, esophagus
- except for air filled trachea & primary bronchi, all these structures have the same radiodensity and can’t be distinguished
- only the lateral borders outlined by air filled lungs can be identified
mediastinum contains:
heart
vessels
trachea
esophagus
mediastinal shifts
-whole structure can move to one side of another and can be permanent (removal of a lung) or temporary (pleural effusion) or atelectasis
- air or fluid in pleural space will push contents (including trachea) to the opposite side;
- lung collapse or volume loss will pull contents to the same side
Can also identify masses in this area
-goiter, lymphoma, esophageal or bronchial cancers, aortic aneurysms
diaphragm
- can see the 2 halves of this muscle bc it borders air-filled lungs
- white area is combined areas of liver, spleen, stomach, posterior lungs and the part of the diaphragm that’s next to the x-ray beam
- dome normally seen on inspiration at level of 10th rib
elevated diaphragm due to:
- excessive fluid in the peritoneal space (ascites (fluid build up) or cirrhosis of the liver)
- later stages of pregnancy
- splinting after abdominal surgery
flattened diaphragm due to:
-increased volume of the lung (emphysema, pleural effusion, or masses in the lung)
hemi-diaphragms
- highest point of each hemi–diaphragm is middle 1/3rd
- R is higher bc of liver
- L contains the stomach-often see a bubble in the funds
costophrenic angles
- seen where diaphragm and chest wall meet.
- angle is about 30 degrees
- angle is obscured on x-ray with diagnosis such as pleural effusion
routine CXR
-includes PA and lateral views
Controversy about lateral view:
- increased radiation exposure
- limited in pediatrics and frail who had difficulty raising arms
- less useful clinical info
abnormally white lungs
1: pneumonia
2: atelectasis
3: pleural effusion
pneumonia
(fluid fills in and around alveoli & bronchi producing consolidation seen on x ray)
- determine which lobe
- represents dozens of pulmonary infections.
- lobe, entire lung, 1 or both
x-ray findings:
- consolidation
- silhouette sign is pneumonia in a lobe that borders the heart or diaphragm
atelectasis
=loss of volume of a portion of a lung, not a disease
results from:
- obstruction in the bronchi (foreign object, mucous plug, cancer)
- compression (pleural effusions, enlarged heart)
- traction (scarring, fibrosis, adhesions)
- responds well to chest PT
- tx depends on cause of collapse
- common post-op due to poor inspiratory effort bc of pain; secretion retention may cause obstruction
atelectasis x-ray
- increased whiteness of collapsed lung-no air
- lobes next to collapse lobe may appear darker
- mediastinum shifts TOWARD collapsed lobe due to lost volume in lobe
- hemidiaphragm will elevate on collapsed side
pleural effusion
=excess fluid in pleural cavity due to infection, heart failure, liver failure, cancer, PE, TB, or trauma
4 types of fluid can collect
-fluid is withdrawn from pleural space and analyzed
types of pleural fluid
1: serous fluid (hydrothorax)
2: blood (hemothorax)
3: chyle= fluid filled with lymph & free fatty acids (chlothorax)
4: pus (pyothorax or empyema)
x-ray findings of pleural effusion
-blunting of costophrenic angle
diagnostic categories for CXR
1: lung field is abnormally white
2: lung field is abnormally black
3: mediastinum is abnormally wide
4: heart is abnormally shaped