Imaging of Circulatory Disturbances Flashcards
What are the modes of anatomical vascular imaging?
Plain films Ultrasound CT MRI Contrast angiography
What are the modes of functional vascular imaging?
Radionuclide imaging
MRI functional imaging
Ultrasound
What are the problems associated with vascular imaging?
Soft tissue contrast
Functional significance of lesion
Determining if treatment is effective
Blood vessels and lumen of hollow viscera not seen very well
What are the ideal properties of a man-made contrast agent in radiology?
Attenuation the same as the surrounding tissues
Not expensive
Inert
Equal distribution in and out of selected body compartments
Painless
Easy to use
What are the properties of iodinated contrast?
Differential x-ray attenuation Inert Stable in selected body compartments Painless Easy to use Cheap
What are the potential problems with iodinated contrast?
Major reactions Renal dysfunction Disturbance of thyroid metabolism Disturbance of clotting Seizures Pulmonary oedema
What are the potential properties of parenteral iodinated contrast?
Metallic taste
Feeling of warmth when injected
Arterial injections may cause micturition or discomfort
Can rarely cause nausea
What needs to be discussed prior to parenteral iodinated contrast use?
Previous contrast allergy
Asthma or atopy
Poor renal function
Metformin use - will need to be stopped before contrast injection
How is catheter angiography carried out?
Vessel punctured and catheterised
Sterile procedure
Contrast injected using pump injector
Rapid series of images acquired
What are the uses of interventional radiology?
Angiography/angioplasty Embolisation Catheter thrombolysis Drainage of abscess Nephrostomy Vertebroplasty
When should angioplasty be used?
In stenosis or occlusions
Sessile/concentric plaques
What are the advantages and disadvantages of angioplasty?
Not as long lasting as surgery but not as dangerous
How can carbon dioxide be used in radiology?
Negative contrast agents
Useful in patients with poor renal function or sensitivity to iodinated contrast agents
What are the potential problems with angioplasty?
Occlusion Dissection Embolisation Rupture Infection
What are the properties of ultrasound scanning?
No radiation dose Quick Non-invasive Resolution vs penetration May be more physiological Operator dependent