John OsborneChief Medical Officer, ClearCardio LLC · Preventive cardiologist and Chief Medical Officer at ClearCardio

How a Cardiac CTA Scan Works

3 Oct 2026 · 1 min

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In this segment of the video, the presenter explains how artificial intelligence (AI) dramatically enhances cardiac CT angiography (CTA) by extracting far more information from the raw scan data than the human eye can perceive. While traditional CT images are limited to about 50 visual shades of gray, the scanner actually captures over 2,000 grayscale levels. AI acts like a set of “glasses” that translate this rich data into a multispectral view—akin to seeing red, green, blue, infrared, ultraviolet, X‑rays, gamma rays, and radar waves—allowing clinicians to detect coronary plaque that would otherwise be invisible. The speaker uses vivid analogies to illustrate the expansion from a limited grayscale palette to a virtually full electromagnetic spectrum, emphasizing AI’s role in revealing hidden disease.

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What AI allows us to do is literally see plaque that we cannot see with our eyes. I always love to say how that compares to our looking at cardiac CT images with and without AI. When we add AI, and here's my analogy, with cardiac CT, we can see about 50 shades of gray from black to white, and that's where the plaque is. The 50 shades of gray between black to white on our CT images. However, all of those millions of pixels that make up those pictures of the heart are not encoded with 50 shades of gray. 50 shades of gray, they're actually encoded and coming out of the C2 machine with over 2,000 shades of gray. So what AI allows us to do is, as I like to explain, without my glasses I can see red, green, and blue. I put on my fancy AI glasses, now I can see red, green, blue, infrared, ultraviolet, X-rays, gamma rays, radar waves, or basically analogous to the entire electromagnetic spectrum that was sitting in the data but where our eyes just couldn't see it.