Angiography refers to the administration of contrast agents into the vascular system. This has traditionally been performed for fluoroscopic imaging, but can also be utilized for cross-sectional imaging (computed tomographic angiography [CTA] or magnetic resonance angiography). The vasculature of the liver is complex and 3-dimensional, yet traditional imaging of the liver and vasculature has relied on 2-dimensional imaging techniques such as radiography, fluoroscopy, and ultrasonography. The adoptionof CT as an advanced diagnostic tool has been substantial over the last 30 years, with increased use of CTA in the last decade. The benefit of cross-sectional imaging, such as CTA or MRA, is the avoidance of selective central catheterization, as only peripheral venous access is required for these techniques. Further, the ability to generate 3-dimensional models from high-resolution CTA has allowed a level of anatomic understanding not previously available. Within the vasculature, cross-sectional imaging has been reported for detailed characterization of vascular malformations, such as portocaval communications,1 vascular ring anomalies,2 and arterial-venous fistulae3. The focus of this lecture is on the technical aspects of CTA in the hepatic vasculature, providing a framework for interpretation of hepatic vascular CTA, with case-based examples of anomalies encountered in dogs and cats.
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