Editing Vascular CT



CTA

* Can be used to image arterial tree from aorta to pedal vessels
* Accurate down to tibial arteries; however, tedious to distinguish calcium and contrast at this level. Overestimation of the severity of a calcified stenosis is common.
* CTA is excellent for carotids, giving better anatomic reference than USS and not impeded by plaque presence.


Imaging kidney vasculature

* CTA and MRA are comparable in sensitivity for detection of proximal RAS. CTA is better for more distal disease, as MRA is affected by breathing artefact.
* MRA does allow contrast to be avoided, but gadolinium can also cause fibrosis in renal failure


Venous disease

* CT is better for central thrombosis (PE, mesenteric venous thrombosis) but USS better for peripheral veins


Vascular malformations

* CTA is only useful in high-flow malformations
* USS/MRI good for low-flow malformations


Shaded surface display (SSD)

* Density of vascular contrast, calcium and bone frequently overlap
* This means that calcifications are usually included as part of the contrast-enhanced vessel lumen
* SSDs show the exterior of the structure as opaque and shaded to provide an appreciation of depth
*

Maximum intensity projection (MIPs)

* Only the structure with maximum intensity is projected
* Plaque is displayed prominently
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[[Category:Radiology]]