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: breathing: lungs, pleural spaces, lung interfaces (silhouette sign)
What are the C and D of the ABCD approach of looking at a CXR?
C: circulation: mediastinum, aortic arch, pulmonary vessels, borders of the heart
D: diaphragm/dem bones: free gas under diaphragm, nodules, fractures, mass
Where are some of the important review areas on a CXR and what pathology might we be looking for?
What is the silhouette sign?
Structures of differing density eg heart muscle and air in lung 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? (3)
- Consolidation
- Fluid
- Hyperinflation of lung
How do you identify a pneumothorax on a CXR?
- Lung edge more than 2cm from chest wall
- Tracheal or mediastinal shift away from pneumothorax is tension
- Visible pleural edge
-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
- Crowding of pulmonary vessels
- Shift of mediastinum towards atelectasis
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 (pattern of air-filled bronchi on a background of airless lung)
What is being shown on this CXR? What could have caused the pathology?
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 (use as reference)
What is being shown on this CXR?
Milliary TB until proven otherwise
(massive lymphohematogenous dissemination of Mycobacterium tuberculosis bacilli)
Apart from x-rays, how else can we image the lungs?
- CT angiogram low dose
- Ultrasound for guiding aspiration and biopsy
- Nuclear medicine CTPA (computed tomographic pulmonary angiography)
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 right 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
What is the difference between a pleural effusion and lung consolidation?
A pleural effusion is a collection of fluid in the space between your chest wall and lungs. A lung consolidation may also be fluid, but it’s inside your lung, so it can’t move when you change positions.
