19 - Radiology 2 Flashcards
What do you need for a chest x-ray to be adequate?
- 1st rib
- Lateral margin of ribs
- Costophrenic angle
What indicates cardiomegaly on a chest x ray?
- Over 50% cardiac thoracic ratio
- Only on PA film
- Think about situs invertus
What are the A and B of the ABCDE approach of looking at a CXR?
A: airway for central trachea and hila
B: lungs, pleural spaces, lung interfaces (silhouette sign)
What are the C and D of the ABCD approach of looking at a CXR?
C: mediastinum, aortic arch, pulmonary vessels, borders of the heart
D: free gas under diaphragm, nodules, fractures, mass
Where are some of the important review areas on a CXR?
What is the silhouette sign?
Structures of differing density form a crisp silhouette so when this is lost there is pathology in an area
How can you tell on a CXR if there is mediastinal shift?
- Check the trachea and the cardiac shadow
- Pushed if there is an increase in volume or pressure (pleural effusion) pulled if decrease (consolidation with lung collapse)
What are some causes of costophrenic blunting on a CXR?
- Consolidation
- Fluid
- Hyperinflation of lung
How do you identify a pneumothorax on a CXR?
- Most commonly due to laceration of visceral pleura or fractured rib
- Lung edge more than 2cm from chest wall it is large
- Tracheal or mediastinal shift away from pneumothorax is tension
- Visible pleural edge and no lung markings beyond this point. Side effected is blacker
How do you identify a pleural effusion on a CXR?
- Collection of fluid so uniform white area
- Loss of costophrenic angle
- Hemidiaphragm obscured
- Meniscus at upper border (not when supine)
How does a lobar lung collapse look on a CXR?
- Elevation of ipsilateral hemidiaphragm
- Crowding of ipsilateral ribs
- Shift of mediastinum towards atelectasis
- Crowding of pulmonary vessels
What are some things that can cause consolidation on a CXR?
Always reassess in 6 weeks to think about cancer
How do you spot consolidation on a CXR?
- Increased opacity
- Air bronchograms
What is being shown on this CXR?
Cavitation which could be due to infarction, abscess, TB, malignancy, septic microthrombi
What are some causes of a space occupying lesion on a CXR?
Vertebral body height is about 3cm
What is being shown on this CXR?
Milliary TB until proven otherwise
Apart from x-rays, how else can we image the lungs?
- CT angiogram low dose
- Ultrasound for guiding aspiration and biopsy
- Nuclear medicine CTPA
What is the best way to treat small cell lung carcinoma?
Chemo and radiotherapy
Identify the abnormalities on this x-ray.
- Space occupying lesion in upper left zone probably due to bronchial carcinoma
- Elevation of left hemidiaphragm due to mass causing a phrenic nerve palsy
Which lung cancer is most likely to cause paraneoplastic syndromes and give some examples of the syndromes it can cause?
- Small cell
- Cushings
- SIADH
Small cell lung carcinoma is also the most likely to cause SVC obstruction, what are some signs of this?
- Raised JVP
- Oedema
- Feeling dizzy
- Change in eye sight
What is the diagnosis and how would you treat this to test for malignancy?
- Right sided pleural effusion
- Aspirate and do cytology to look for malignancy
