What does the Z-axis represent in CT imaging?

In computed tomography (CT) imaging, the Z-axis represents the longitudinal dimension, which is the direction that runs along the length of the body. This axis is critical for understanding how images are acquired and reconstructed during a CT scan.

The Z-axis is typically oriented vertically in the context of axial (transverse) images, where the X-axis and Y-axis represent the horizontal and vertical planes of the imaging surface, respectively. The scan data collected along the Z-axis provides the physician with information about the depth or distance of structures within the body, allowing for detailed three-dimensional reconstructions of anatomical features.

Understanding the Z-axis as the longitudinal dimension is important for interpreting CT images, as it influences how slices are taken and how anatomy is visualized across different levels in the body's length. This contributes to accurate diagnosis and treatment planning based on the spatial relationships of structures.