In fluoroscopic imaging with barium, the resulting image typically has which scale of contrast?

• A. Long scale contrast
• B. Short scale contrast
• C. Medium scale contrast
• D. No grayscale

Answer: (B)

Contrast scale describes how many gray levels appear in an image. In fluoroscopic imaging with barium, the contrast medium is highly radiopaque, creating a strong difference in X-ray attenuation between the barium-filled lumen and surrounding tissues. Because of this large attenuation difference and the typical imaging settings, the image shows a high contrast with only a few gray tones—bright white where the barium is, dark areas elsewhere, and limited mid-gray values. This is a short-scale (high-contrast) image.

Images with many intermediate gray tones (long-scale) aren’t typical here, since the dense barium pushes the display toward stark black-and-white separation. And there are grayscale transitions at borders, so it isn’t accurate to describe it as no grayscale.