Chest X-Ray 2 Flashcards
What is the difference between a PA and an AP x-ray?
PA = standing and X-Ray source hits from back. Patients are also suaully asked to lift arms so that the scapula’s are out of the way/
AP= sitting and X-Ray source hits from the front.
Both are viewed from the from/
What do we need to see on an x-ray (inclusion)?
- 1st rib
- Lateral margin of ribs
- Costophrenic angle
How can you tell if the x-ray is rotated?
Aligment of:
- Spinous process
- Clavicles
How many ribs shoudl you be able to see in a normal inspiratory phase?
5th-7th anterior ribs at midclavicular line
What are the problems with incomplete inspiration or exaggerated expnsion?
Incomplete inspiration:
- Big heart
- Increased lung markings
Exaggerated expansion:
- Obstructive airway disease (COPD - barrel chest)
What is penetration of x-ray and how do you check it is adequate?
Penetration is the degree to which the x-rays have passed through the body.
Adequate penetration:
- Vertebral body just visible through the heart
- Complete left hemidiaphragm visible
Digital manipulation often negates this.
What is the best systematic way to approach an x-ray?
Take an ABC approach
- Patient demographics
- Projection
- Adequacy (rotation, inspiration, penetration)
- Airway (trachea, bronchi, hila)
- Breathing (lungs, pleural spaces, lung interfaces)
- Circulation (mediastinum, aortic arch, polmonary vessels -hila, right heart border -RA & middle lobe interface, left heart border - LV & lingula interface)
- Diaphragm / Dem bones (free gas, nodules, fractures / dislocations, mass)
- Review areas
What are the review areas of the lung?
- Apices
- Thoracic inlet
- Paratracheal window
- AP widnow (bit between aorta and pulmonary artery)
- Hila
- Behind heart
- Below diaphragm
- Bones -all!
- Edge of films
What common pathologies are you looking for in these review areas?
- Apices
- Thoracic inlet
- Paratracheal window
- AP widnow (bit between aorta and pulmonary artery)
- Hila
- Behind heart
- Below diaphragm
- Bones -all!
- Apices - pneumothorax
- Thoracic inlet -Mass
- Paratracheal window -Mass / lymph nodes
- AP widnow - Lymph nodes
- Hila - Mass / collapse
- Behind heart - Mass
- Below diaphragm - Pneumoperitoneum / mass
- Bones -all! - fracture / mass / missing
What is the silhouette sign and how can this helpup locate pathology?
Ina chest x-ray, adjacent structures of different density form a crisp silhouette. If this contour is lost, we can locate pathology.
If the silhouette sign is lost here, where is the pathology?
- Right heart border
- Ledt heart border
- Paratracheal stripe
- Chest wall
- Aortic knucke
- Diaphragm
- Horizontal fissure
- Right heart border - RML
- Ledt heart border - lingula
- Paratracheal stripe - mediastinal disease
- Chest wall - ling / pleura / rib
- Aortic knucke - anterior mediastinum / upper lobe
- Diaphragm - lower lobe
- Horizontal fissure - anterior segment of upper lobe
How do you work out if there is mediastinal shift and what does it tell you?
Look at:
- Trachea (can you see spinous processes through it?)
- Cardiac shadow
Pushed or pulled?
- Push = increased volume or pressure (tension pneumothorax or pleural effusion)
- Pull =decreased volume or pressure
What is a pneumothorax?
- Air trapped in the pleural space
- Spontaneous (primary) or as a result of underlying lung disease (secondary)
- The most common cause is trauma, wiht laceration of the visceral pleura by a fractures rib.
- Lung edge measures more than 2cm from the inner chest wall at the level of the hilum, it is comsidered to be large.
- Tracheal or mediastinal shift away fromt he pneumothorax and depressed hemidiaphragm, the pneumothorax is said to be under tension.
- Signs:
- Visible pleural edge
- Lung markings not visible beyong this edge
What is a pleural effusion?
- Collection of fluid in the pleural space
- Uniform white area
- Loss of costophrenic angle
- Hemi-diaphragm obscured
- Minuscus at upper border
What is a lobar lung collapse?
Volume loss within lung lobe
- On CXR you will see:
- Elevation of the ipsilateral hemidiaphragm (less space)
- Crowding of the ipsilateral ribs
- Shift of the mediastinum towards the side of atelectasis
- Crowding of pulmonary vessels
What are the causes of a lobar lung collapse?
- Luminal
- Aspirated foreign materal
- Mucous plugging
- Iatrogenic
- Mural
- Bronchogenic carcinoma
- Extrinsic
- Compression by adjacent mass
What is consolidation?
- Filling of small airways / alveoli wiht stuff
- Pus -pneumonia
- Blood - haemorrhage
- Fluid - oedema
- Cells - cacer
- Dense opacification
- Volume preserved +/ increased
- Air bronchogram
What are the different types of space occupying lesions?
- Nodule - under 3cm
- Mass - over 3cm
- It is also important to note if there are single or multiple lesions as it will help differentiate the cause.
What are some causes of space occupying lesions?
- Malignant
- Primary
- Metastates
- Benign mass lesions
- Inflammatory
- Congenital
- Minics
- Bone lesions
- Cutaneous lesions
- Nipple shadow
What is the cardiac index?
This is how much of the chest wall the heart takes up (as a ratio)
- The normal ratio is under 50%
- This must be on a PA image as on an AP, it is overetimated.
