Imaging Circulatory Disturbances Flashcards
What questions should be asked for vascular imaging?
What is the anatomy
Is there a leak
Is there a blockage
Can it be fixed
What are anatomical vascular imaging?
Plain films
Contrast angiography
Ultrasound
CT/MRI
What are functional vascular imaging?
Radionuclide imaging
MRI functional imaging
Ultrasound
What are some problems with vascular imaging?
Soft tissue contrast (cannot see important structures like blood vessels and lumen of hollow viscera)
Functional significance of lesions
Is treatment effective
What are the ideal properties of a manmade contrast agent in radiology?
Has an attenuation the same as the surrounding tissues
Inexpensive
Inert (chemically inactive)
Equial distribution in and out of selected body compartments
Painless
Easy to use
What does inert mean?
Chemically inactive
What are some examples of different contrasts?
Iodinated contrast
Parenteral iodinated contrast
Carbon dioxide
What does parenteral mean?
Administered elsewhere than the mouth
What are advantages of iodinated contrast?
Differential X-ray attenuation
Inert
Stable in selected body compartments
Painless
Easy to use
Cheap
What are disadvantages of iodinated contrast?
Major reactions
Renal dysfunction
Disturbance of thyroid metabolism
Disturbance of clotting
Seizures
Pulmonary oedema
What kind of contrast agent is carbon dioxide?
Negative contrast agent (appears radiolucent due to low density, instead of typical substances that are radiopque with high density)
In what patients is using carbon dioxide as contrast useful?
Patients with poor renal function
What is used to get contrast into vessels?
Catheter angiography
What is the process of catheter angiography to get contrast into vessles?
1) Vessel punctured and catheterised
2) Contrast injected using pump injector
3) Rapid series of images acquired
What are things that can be treated using intervention radiology (with minimal invasion)?
Angiography/angioplasty
Embolisation
Catheter thrombolysis
Drainage of abscesses
Nephrostomy
Vertebroplasty
What is nephrostomy?
An opening between the kidney and skin
What is vertebroplasty?
Procedure to stabilising compression fractures in the spine
What is a procedure for stabilising compression fractures in the spine?
Vertebroplasty
When should angiography be used?
Short stenosis or occlusions
Sessile (immobile) or concentric (share the same centre) plaques
Why is an advantage and disadvantage of angiography compared to surgery?
Not as long lasting, but not as dangerous
What is angiography?
Imaging technique used to visualise the lumen of blood vessels and organs
What is angioplasty?
Minimally invasive procedure used to widen arteries
What are problems with angioplasty?
Occlusion
Dissection
Embolisation
Rupture
Infection
What are advantages of ultrasound of vascular disturbances?
No radiation dose
Quick
Non-invasive
What is a disadvantage of ultrasound of vascular disturbances?
Operator dependant
How can you identify deep vein thrombosis using ultrasound?
When using ultrasound the vein is full of thrombus and is not compressible, whereas a normal vein has low pressure and is compressible
What is radionuclide imaging of vascular disturbances used to show?
Perfusion or blood lose
What are advantages of CT angiogram for vascular disturbances?
Gives information about other structures
Sensitive
What are disadvantages of CT angiogram for vascular disturbances?
IV injection only
Radiation dose
High contrast dose
Expensive
What are advantages of magnetic resonance angiography?
Sensitive
Specific
No radiation
No nephrotoxic contrast
What are disadvantages of MRI angiography?
Expensive
Needs state of the art machinery
High contrast cost
What can be said about consent in radiology?
It is a process where the patient learns key facts about the investigation/treatment including risks before deciding to proceed, where informed consent continuous throughout the procedure
Who should obtain consent in radiology from patients?
Not newly qualified doctors, the doctor performing the procedure should
Why could renal failure be a contraindication to the use of certain contrast?
The contrast may induce nephropathy
What kinds of adverse reactions could contrast agents induce?
Ranges from mild rash to severe such as acute anaphylaxis
May precipitate asthma
