Radiology 1 and 2 Flashcards
What is the Xray dose for a CXR?
0.02mSv
What is the Xray dose for a Chest CT?
10mSv
On average how much background radiation does the average person absorb?
2.2mSv/yr
From darkest to lightest describe the different densities in an Xray?
Darkest Air Fat Soft tissue Bone Metal Lightest
Is it better to take a breath out and hold or breath in and hold when having an xray?
Taking a breath in so you can see more of the lungs and chest
What is the lingula and where is it?
The left lung, unlike the right, does not have middle lobe, though it does have a homologous feature, a projection of the upper lobe termed the “lingula”. Its name means “little tongue”. The lingula on the left serves as an anatomic parallel to the right middle lobe, with both areas being predisposed to similar infections and anatomic complications.There are two bronchopulmonary segments of the lingula: superior and inferior.
What is the difference when looking at the lung posteriorly, lobe wise?
The lower lobes overlap the other lobes so it may be hard to distinguish if an abnormality lies within the middle of lower lobe.
If you can still still the boarders of the right side of the heart what does that mean in terms of the middle lobe being affected?
The middle lobe is usually fine if you can still see the boarders of the heart.
In a suspected PE what should you do if the CXR is normal?
A V/Q scan
In a suspected PE what should you do if radiation needs to be avoided/the leg is swollen?
Ultrasound for leg for DVT
In a suspected PE what should you do if the CXR has an abnormal/massive PE suspected?
CT Pulmonary Angiogram
What are the clinical features and pathology of lung cancer?
Asymptomatic (15% to 25% at diagnosis) especially peripheral tumours.
Symptoms: cough, wheeze, haemoptysis, recurrent pneumonia, hypercalcemia, Weight loss, hoarseness, finger clubbing, persistent supra-clavicle nodes
What are some predisposing conditions to lung canceR?
Inhalation of carcinogens e.g. cigarette smoke, asbestos
Bronchioalveolar adenoma
Lipoid pneumonia
Interstitial pulmonary fibrosis
Previous lung cancer. Remember tumours can be synchronous and metachronous
NOT in Scars due to old TB
What are peripheral tumours?
Tumours arising beyond the hilum
What are central tumours?
Tumours arising at or close to the hilum
What are some cardinal signs of a central tumour?
Hilar enlargement
Distal collapse/consolidation
When is contract enhance CT good for in terms of staging cancer?
Assessing tumour size
showing intracranial metastases
Guiding a biopsy of peripheral lesions
When is a PET CT good in terms of staging cancer?
Nodal metastases
Distant metastases (not brain metastases)
Delineating tumour in an area of collapse
When is an MR good for staging cancer?
Does not require IV contrast to see vessels
3 planes valuable at apex, aortopulmonary window and supradiaphramtic regions
Better soft tissue differentiation
HOWEVER
Costly
Time-consuming
Spatial resolution better with CT
Need gating to reduce motion artefacts
Why in general is a PET scan good to find cancer?
Cancer requires glucose to survive, shows up very well on PET scan
Name some radiological interventions?
CT guided lung biopsy
Pleural fluid drain
SVC stenting
In what position are X-rays usually taken?
PA
What are the disadvantages in an AP X-ray in someone who is unable to get an PA CXR?
The heart shadow is magnified so heart size cannot be assessed accurately
The scapulae overlie and partly obscure the lungs
It can be difficult for the patient to take an adequate inspiration
How many ribs should be visible if the CXR is adequately inspired?
At least 6 ribs - anterior ends
At least 10 ribs - posterior (easier to see)
