Vascular Interventional Radiology Flashcards
Give 3 common vascular diseases?
1) Acute lower limb ischaemia
2) Chronic ischaemia
3) Aneurysm disease
What are the 2 broad ways of imaging the vascular system?
Invasive (involves needles/scalpels)
Non invasive
Give 3 non invasive modalities of imaging the vascular system?
1) Duplex scanning (US Doppler)
2) MR Angiography (MRI of vessels)
3) CT angiography
Give an invasive way of imaging the vascular system?
Catheter/Contrast angiography
What are the 3 advantages and 1 disadvantage of duplex scanning (USS)?
Advantages:
1) No ionising radiation (good for use in pregnancy)
2) Readily available
3) Velocity and volume measurements can be obtained
Disadvantages:
1) Operator dependent - ie. can only be interpreted by the operator then and there, do not produce an image which can be interpreted by others
What is the major advantage of CT angiography and one disadvantage?
Advantage = readily available Disadvantage = uses x-rays
Give 3 uses of CT angiography in vascular disease?
1) Assessment of aortic aneurysms
2) Assessment of bleeding
3) Assessment of peripheral vessels
What is multiplanar formatting sometimes used in CTA (CT angiography)?
CT scans traditionally taken in axial plane, computers can now reformat the image to give an image in coronal plane, saggital plane etc.
What are the 2 advantages and 3 disadvantages of MR Angiography (MRA)?
Advantages: 1) Non invasive 2) No ionising radiation Disadvantages: 1) Not as readily available 2) Overestimates stenosis 3) Not suitable for all patients
Name 3 groups of patients for which MRA would not be suitable?
1) Claustrophobia
2) Pacemakers
3) Prostheses/ metal work
Which imaging technique is gold standard for vascular imaging?
Contrast/ catheter angiography
Contrast/ Catheter angiography is deemed an invasive procedure for what 2 reasons?
1) Procedure related: ie have to gain access to body
2) Contrast related: injecting contrast into someones blood stream
Why is the common femoral artery over the femoral head a good point of access for catheter angiography?
It is a relatively superficial artery
In its position over femoral head, the bone provides a hard surface to compress the artery against in order to achieve haemostasis
What are the 2 possible access complications in catheter angiography?
1) Haematoma at point of access
2) Pseudoaneurysm
What is a pseudoaneurysm?
A hematoma which forms as a result of a leaking hole in an artery. The haematoma forms outside of the arterial wall so to be considered a pseudoaneurysm the haematoma must continue to communicate with the artery
What are the 2 possible contrast mediums used in catheter angiography?
1) Iodinated contrast
2) CO2
When would CO2 be used as a contrast medium and what is the disadvantage?
Can be used in patients with renal impairment (iodinated contrast is nephrotoxic) and possible those who are allergic
Disadvantage is that it is quite painful for the patient
What is interventional radiology?
The use of imaging techniques to effect treatment rather than simply diagnose, it is a minimally invasive alternative to surgery
How can interventional radiology be used to treat haemorrhage?
Through embolization of the vessels which are bleeding using a catheter. Embolisation can be achieved using different mediums such as metal coils or glue.
What is subtraction angiography?
Take images without contrast. Add contrast and take further images then subtract the image without contrast from the image with contrast. Are left with an image showing only the vessels
Give 4 situations in which interventional radiography could be used to stop haemorrhage?
1) Trauma
2) GI bleeding
3) Post-partum haemorrhage
4) Haemoptysis (embolise the bronchial arteries, a lot of respiratory pts die due to choking on blood so this prevents that)
Interventional radiology can also use embolization in non-haemorrhagic conditions, name 3 non-haemorrhagic uses of embolization?
1) Chemoembolization
2) Selective internal radiotherapy (SIRT)
3) Uterine artery embolization (to treat fibroids and stop symptoms of menorrhagia and pain)
What is meant by chemoembolization and selective internal radiotherapy?
Used in oncology, palliative treatments, not yet curative, used in patients where there is no option of surgical resection. Catheter is used to inject chemotherapy or radiotherapy beads directly into the small vessels recruited by the tumour to supply it. The vessels are then embolized.
Other than SIRT of chemoembolization, name another use of interventional radiology in oncology?
Tumour stenting - ie. stenting a structure such as the oesophagus or GI tract to prevent occlusion by a tumour
