Chest X-rays Flashcards
What are X-rays?
- Diagnostic tool in medicine and dentistry
- Images produced by passing a certain wavelength of radiation through an object
White: radiopaque or radiodense
(The greater the density of the object, the less the penetration of the x-rays through it)
Black: radiolucent
(The less dense object allows more x-rays to penetrate it)
What colour do bones show up on an X-ray?
White
What colour does water show up on an X-ray?
White/grey
What colour does fat show up on an X-ray?
Grey/white
What colour does air show up on an X-ray?
Black
What colour does metal show up on an X-ray?
White
What view is ‘AP’?
Anteroposterior
What view is ‘PA’?
Posteroanterior
Describe posteroanterior (PA) view of X-ray.
- Beam passes through the chest from back to front
- Patient must stand whilst CXR is taken
Describe the anteroposterior (AP) view of X-ray.
- Beam passes through the chest from the front to the back
- Portable CXR’s performed at patients bedside are AP
Why is Posteroanterior (PA) view of X-ray preferred over Anteroposterior (AP)?
- Structures in the anterior part of the chest appear larger (i.e heart due to magnification)
- Potential interference in image from scapulae
- Could lead to incorrect diagnosis of cardiomegaly
Why would a lateral view X-ray be done?
- May reveal lesions behind the heart near the mediastinum or near the diaphragm
- Together with a frontal view, the lateral can provide a 3-D view of the chest
What is the systemic approach to X-rays?
Check:
- Patient’s first and last name, dob, hospital number
- Note X-ray time and date
- Note the view/projection: PA, AP or lateral (departmental films are PA, portable films are AP)
- Ensure the X-ray is the right way round
Exposure:
- Over exposed appears too black while under exposed appears too white
- Check exposure: if good the vertebral bodies should be visible throughout upper but not lower heart shadow
What does ABCDEF stand for in X-ray?
A: Airway
B: Bones
C: Cardiac
D: Diaphragm
E: Everything/Exposure (soft tissue, lines/airways)
F: Fields
What do you need to consider about airways in an X-ray?
Trachea:
- Position: displaced?
- Black: air should be present
- ET tube or tracheostomy
- Carina and Right Left Main Bronchus as they divide from trachea
Where do the ribs sit on full inspiration in an X-ray?
The midpoint of the right hemidiaphragm lies between:
- The 5th – 7th ribs anteriorly
- The 8th – 10th ribs posteriorly
What do you need to consider about bones in an X-ray?
- White: due to denseness
- Alignment of clavicles
- Count Ribs:
~ Hemidiaphragm should be between the 5th and 7th rib anteriorly
~ 10 posterior ribs visible
~ 6 anterior ribs visible
~ Rib crowding - Spinal Alignment: any sign of scoliosis
What are the bones of the thoracic cage that will show up on an X-ray?
- Clavicular level
- Rib markings (check for fractures)
- Identify the scapula borders (sometimes mistaken for a pneumothorax)
- Vertebral and spinous processes
What are the soft tissues of the thoracic cage that will show up on an X-ray?
- Breast shadows
- Surgical emphysema under the skin
What do you need to consider about cardiac wise in an X-ray?
Positioning, Size & Shape:
- 1/3 right of spine
- 2/3 left of spine
Aortic Notch Visible:
- ? LUL collapse or consolidation
Hilar Markings:
- Left will be slightly higher due to left main pulmonary artery
Borders (silhouette sign):
- Indicative of right middle lobe collapse/consolidation
What are the (2) normal heart contours that will show up on an X-ray?
Left heart contour:
- Left lateral border of Left Ventricle (LV)
Right heart contour:
- Right lateral border of the Right Atrium (RA)
What is the costophrenic angle?
Angle formed by lungs & ribs
What is the costophrenic angle obliterated by?
- Meniscus of small pleural effusion –> (200 ml. of fluid needs to accumulate in the pleura before blunting the costophrenic angle)
- Patchy shadowing of consolidation
- Chronic atelectasis
- Lung hyperexpansion (pushes diaphragm domes down, rounding the angle)
What are examples of artefacts which will show up on an X-ray?
- Endotracheal Tube
- Tracheostomy / Mini-trach
- Nasogastric tube
- ECG leads
- Central line
- Chest Drain
- Other
Describe the aortic notch.
- The aortic knuckle represents the left lateral edge of the aorta as it arches backwards over the left main bronchus, and pulmonary vessels.
- The contour of the descending thoracic aorta can be seen in continuation from the aortic knuckle.
Which lobe is collapsed or consolidated if the left hemi-diaphragm border is obscured?
Left lower lobe
Which lobe is collapsed or consolidated if the right hemi-diaphragm border is obscured?
Right lower lobe
Which lobe is collapsed or consolidated if the aortic arch border is obscured?
Left upper lobe
Which lobe is collapsed or consolidated if the right upper mediastinum border is obscured?
Right upper lobe
Which lobe is collapsed or consolidated if the left heart border is obscured?
Lingula
Which lobe is collapsed or consolidated if the right heart border is obscured?
Middle lobe
Which border is obscured if the left lower lobe of the lung has collapsed or consolidated?
Left hemi-diaphragm
Which border is obscured if the right lower lobe of the lung has collapsed or consolidated?
Right hemi-diaphragm
Which border is obscured if the left upper lobe of the lung has collapsed or consolidated?
Aortic arch
Which border is obscured if the right upper lobe of the lung has collapsed or consolidated?
Right upper mediastinum
Which border is obscured if the lingula lobe of the lung has collapsed or consolidated?
Left heart border
Which border is obscured if the middle lobe of the lung has collapsed or consolidated?
Right heart border
