Type:
Educational Exhibit
Keywords:
Vascular, CT-Angiography, Computer Applications-Detection, diagnosis, Computer Applications-3D, Embolism / Thrombosis
Authors:
K. K. Lau, D. Jackson, A. Kuganesan; Melbourne/AU
DOI:
10.1594/ranzcr2015/R-0114
Background
CT angiography (CTA) has been established as the first line imaging modality for evaluation of vascular anatomy and pathology. It plays a vital role in diagnosing and monitoring conditions such as stenosis,
occlusion,
thrombo-embolism,
aneurysm,
dissection,
bleed and endoleak of a stent graft.
Its advantages in comparison to digital subtraction angiography (DSA) are shorter acquisition time,
non-invasive nature,
less procedural complications and the ability to study soft tissue structures around the blood vessels.
These are especially useful in the emergency setting.
CT angiographic image quality is described in terms of contrast,
spatial resolution,
image noise and artifacts.
The vessel assessment on CTA can be limited by a) motion,
such as from cardiac and aortic pulsations and breathing (Figure 1),
b) beam-hardening artifacts from vessel wall calcifications and adjacent metallic clips and coils that can obscure the vessel lumen,
and c) poor contrast opacification of vessel lumen due to inadequate contrast dose,
cardiac dysfunction,
arterial or venous steosis,
contrast column interruption related to breath-hold or wrong timing of CT acquisition.