Lecture 2: Chest X Rays Flashcards
What are the ‘Shuns’
Identification Projection Position/Rotation Penetration Inspiration
What are the types of projection?
PA: posterior anterior
Done while standing
AP: anterior posterior
Used for patients who are non ambulatory
Which is preferred? Why?
PA
With an AP film, the beam hits the anterior structure (heart) first and scatters. Therefore, heart may appear enlarged in an AP film. If heart takes up entire hemithorax space - cardiomegaly but do not know to what extent.
What occurs if you don’t have proper position?
If the patient is rotated, may appear as mediastinal shift
What is the proper penetration?
Should barely be able to see the thoracic spine disk spaces.
If the penetration is off (over or under) then may miss a finding
Sizing for pulmonary nodule vs pulmonary mass
Nodule: 3 cm
What’s the order from least dense to most in a radiograph? What color would least dense and most dense object appear on a radiograph?
Least dense= black Air Fat Soft tissue Calcium Bone Contrast Metal Most dense= white
At inspiration, where is the diaphragm?
8th - 10th posterior rib
5th - 6th anterior rib
Why do you want the patient to take a deep breath when taking a chest X-ray?
If the patient does not take a deep breath in while taking the X Ray:
- heart size is prominent
- peri hilar areas are full
- see interstitial markings
When the patient is in full inspiration
- diaphragm drops down and the image clears up so you don’t over-read certain findings
Anatomy in the chest X-Ray.
ABCDE
Air Bones Cardiovascular Diaphragm Everything else
Air
Trachea - make sure it’s midline
Carina- bifurcation of the trachea
Bronchi-> airways: look at the lungs as upper, middle and lower thirds
Bones
Look at your clavicles (lined up) ribs (check through them to see if there’s lung pathology) and any bone that appears on the film. Check for fractures.
Cardiovascular inspection.
What are the contours?
Look at the shape and size of the heart
Clear cardiac silhouette
Left: Aortic arch Pulmonary trunk Left atrium Left ventricle
Right:
Right Atrium
Diaphragm inspection
Make sure there are two. If there is only one visible
- fluid obscuring it (pleural effusion)
- consolidation (pneumonia)
- atelactasis so (partial lung collapse)
Too much air under the diaphragm
- perforated ab viscera
Everything else (inspection)
Look outside the lungs
Under the diaphragm, may miss pneumonia/nodule
Make sure gastric air bubble is present
Check for external hardware
What is the advantage of a lateral X ray
Can see the area behind heart, retrocardiac space (in the posterior mediastinum?) should be clear
Seen in the mediastinum: What are the Terrible T’s?
Thymus
Thyroid
Teratomas
Terrible lymphoma
What are potato lymph nodes? How do they appear on a lateral X-Ray?
Large hilar lymph nodes
(Enlarged hilar and mediastinal lymph nodes are indicative of sarcoidosis)
Donut sign
What is an air bronchogram?
Visualization of air in the intrapulmonary bronchi
What does alveolar filling look like? What are underling pathologies of an abnormal bronchogram?
White shadows - can see the subdivisions of airways
Alveolar filling
- pus: pneumonia
- water: edema
- blood: hemorrhage
- protein: alveolar proteinosis
- cells: alveolar cell carcinoma
If you get an abnormal film, what should you do?
Follow up film 6-8 weeks to make sure abnormality is not there anymore
How do you determine interstitial abnormalities? What are the different type of interstitial patterns?
Follow the ‘lines’ from the hilum to the periphery to make sure it’s an abnormality and not just the vessels.
(Vessels get smaller and smaller-> should not be able to see towards the periphery)
Linear
Reticular
Nodular
Reticulonodular
What’s a miliary pattern?
Many tiny diffuse dots seen on X-ray or CT scan
Indicative of the most infective form of TB
What is a mycetoma? What’s a commone cause? What’s a common complication?
Movable fungus ball in a lung cavity.
Most often due to aspergillus (aspergilloma)
It has neovascularization, when it moves, bounces into immature blood vessels-> bleeding is a major complication.
What is a pneumothorax?
Lung collapses, air in pleural space
What is diaphragmatic calcification indicative of?
Asbestos exposure
Can be seen with pleural plaques
Pleural effusion
Fluid in the pleura
Looks like a white shadow
White outs can be due to __?
What helps with determining underlying pathology?
Lung completely filled with fluid
Lung completely collapsed
Mediastinal shift helps with diagnosis
A barrel shaped chest is indicative of ___? How does it look like?
COPD
Hyper inflated lungs within rib cage. Ribs are fairly straight (not as curved) and the apex of the heart is more medial (PMI felt below the sternum)
Ectatic aorta
Floppy aorta, does not stay in place (seen in an X-ray of an older person)
How do you tell if an opacity is a pleural or lung based lesion?
Look at the angle of opacity
Obtuse - tends to be more of pleural origin (but not always the case)
How can you tell if there’s a tension pneumothorax?
Collapsed lung - can see a clear demarcated separation of lung and air in pleura.
If mediastinum is shifter in the contra lateral direction of the collapsed lung - tension pneumothorax
Which side of the diaphragm is normally lower?
Left
What are some reasons why the diaphragm may be elevated?
Cervical spine injury
Phrenic nerve injury
Pericardial injury
Splinting due to pain
What is splinting?
When a patient is in pain due to traumatic injury, the lung on the side of trauma will not inflate as much (breathing less on the injured side).
