What is the primary characteristic of brightness in B-mode imaging?

In B-mode imaging, the primary characteristic of brightness is closely linked to the amplitude of the echoes received from different tissues. B-mode, or brightness mode, creates two-dimensional images by displaying the intensity of echoes that are reflected back to the transducer from structures within the body. These echoes vary in strength depending on the properties of the tissues they encounter, which translates into varying levels of brightness on the display.

When a sound wave is emitted, it interacts with the tissues, and the reflected echoes have different amplitudes based on factors like tissue density and composition. The greater the amplitude of the returning echo, the brighter the pixel will appear on the ultrasound image. This allows the sonographer to assess not only the location of structures but also their relative characteristics based on the brightness levels.

The role of echo amplitude in determining brightness is fundamental to the interpretation of B-mode images, making this choice the most accurate representation of the concept.