Radiology Of The Thorax Flashcards
What colour does air show up on a radiograph?
Black
What colour does fat, soft tissue and muscle show up on 9 radiograph?
Grey
What colour does bone and metal show up on a radiograph?
White
How does the number of electrons affect the colour of a radiograph?
The larger the number of electrons, the darker it appears as it block X-rays.
What colour does fluid show up on an ultrasound?
Fluid allows the passage of soundwaves and is therefore black.
What colour does soft tissue show up on an ultrasound?
Soft tissue allows passage of sound waves and is therefore bright
What colour does air and bone show upon an ultrasound?
Air and bone blocks passage of sound waves and is therefore a shadow
How should a patient be positioned for a chest X-ray?y
- Patient stands 2m from apparatus
- Shoulders are braced so as not to obscure the lungs.
- Taken on an ‘in breath’.
What must you check before analysing an X-ray?
Is it the right patient? Was it on the correct day? Is it the right way round? Is it adequate - annotation, inspiration, rotation and penetration?
Name the mediastinal borders.
Aorta Pulmonary Artery Left Auricle Left Ventricle Right Atrium Trachea Right Hemidiaphragm Stomach Bubble Horizontal Fissure
Which lobes can be viewed from an anterior view?
Right upper lobe
Right middle lobe
Left upper lobe
Ligula
Which lobes can be viewed from a posterior view?
Right lower lobe
Left lower lobe
What features can be viewed from a lateral radiograph?
Oblique fissure
Horizontal fissure
Posterior costophrenic recess
Retrosternal space
What imaging should we do for a pulmonary thromboembolism?
If CXR normal - V/Q scan
If radiation to be avoided and DVT suspected- U/S on leg
If CXR abnormal - CT Pulmonary angiogram
When is a V/Q scan considered abnormal?
When there is a ventilation perfusion mismatch, e.g the ventilation is normal and perfusion is abnormal or vice versa.
What is a hamartoma?
A hamartoma is a noncancerous tumor made of an abnormal mixture of normal tissues and cells from the area in which it grows.
It shows up of a CT angiogram as popcorn calcification
What are some predisposing conditions to lung cancer?
Inhalation of carcinogens Bronchioalveolar adenoma Lipoid pneumonia Interstitial pulmonary fibrosis Previous lung cancer
What is a synchronous tumour?
This is when tumours are occurring at the same time as another cancer.
What is a metachronous tumour?
This when a tumour occurs after another cancer.
How does asbestosis show on a HRCT?
It will show up as calcified pleural plaque in the pleura
What is a peripheral lung cancer tumour?
This is tumours arising beyond the hilum
What is a central lung cancer tumour?
This is tumours arising at or close to the hilum
How long does it take for a peripheral tumour to double in size?
Between 40 and 400 days. This is therefore useful because if a patients tumour grows in 20 days, we can rule out lung cancer
What are the cardinal signs for central lung cancer tumours?
Hilar enlargement
Distal collapse/ consolidation
What are Contrast Enhanced CT scans good for in lung cancer?
They are good for -
Assessing Tumour SIze
Showing Intracranial Metastases
Guiding a biopsy of peripheral lesions
What are PET CT scans good for in lung cancer?
They are good for -
Detecting nodal metastases
Detecting distant metastases
Delineating tumour in an area of collapse.
They are not good for dectecting brain metastases
Why do tumours show up on a PET scan?
Because a fluid is used for imaging that goes to areas with a high metabolism of glucose. It will there for go to the tumour
Why are MR scans good for the staging of a lung cancer tumour?
It doesn’t require IV contrast to see vessels.
It is on 3 planes
It has better soft tissue differentiation
Why are MR scans not good for the staging of a lung cancer tumour?
Costly
Time-consuming
Spatial resolution better with CT
Need gating to reduce motion artefacts
What are common metastases from lung cancer?
Pleural, lung, bone, adrenal, brain, liver
What are radiological interventions for small cell lung cancer?
CT guided lung biopsy
Pleural fluid drain
SVC stenting
What would an ultrasound be used for at the chest?
Pleural effusion
Subphrenic collection - fluid between the diaphragm, liver and spleen
Assess movement of the diaphragm
US guided drainage
