Angiography. [Review]

Medical imaging has benefitted from a boom in innovation in the past 50 years, which has allowed for rapid development in the field of interventional radiology. Angiography is used to image anatomical and structural details of the vascular system by detecting contrast injected into a blood vessel and projecting this on a series of x-rays to outline the inner vessel wall and show flow through the lumen. Starting as a diagnostic tool, angiography underwent a technological transformation over the last century and became a basis for interventional therapy as well. Angiography, initially a static two-dimensional record of the vasculature on screen-films, has evolved to a real-time two-dimensional display of the vasculature on television screens, and three- dimensional reconstruction from computed tomographic scans. Angiography has many advantages as it achieves real-time, dynamic imaging using a traditional imaging device - such as x-rays or computed tomography (CT), and it also offers therapeutic options at the time of initial diagnosis. Conventional angiography is invasive. In addition to providing therapeutic options, invasive angiography remains the gold standard in diagnosing most intravascular pathologies. Advances in imaging technology in the last three decades have expanded the scope of angiography to include non-invasive techniques using CT and magnetic resonance imaging technologies. In CT angiography (CTA), intravenous contrast is administered via a peripheral vein, and triple-phase CT is usually acquired. CTA is based on high-resolution CT data acquisition, with subsequent angiographic two or three-dimensional reconstruction. Advances and adaptations of CTA principles have been of immense benefit to patients with cardiovascular diseases. Whereas this is an excellent first-line investigation and offers information regarding the surrounding soft tissues, it is less useful in investigating blood flow to the extremities due to the small diameter. Interventional angiography provides higher resolution imaging and can detect changes in the small vessels.[1] Magnetic resonance angiography (MRA): Clinical applications of MRA have become more salient for the patient and the clinician, especially in this era of rapid advances in imaging techniques. Magnetic resonance imaging (MRI) relies on the intrinsic magnetic trait of body tissues in an external magnetic field. It does not require ionizing radiation.[2] The details of CTA and MRA are beyond the scope of this review. Copyright (c) 2020, StatPearls Publishing LLC.

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