Changing the slice thickness of a sagittal reformation affects the dimensions of the image data in which axis?

When changing the slice thickness of a sagittal reformation, the primary effect is on the Z-axis, which corresponds to the axis aligned with the direction of the slices. In CT imaging, the Z-axis represents the depth of the slices as they are reconstructed across the body.

In a sagittal reformation, the images are created by slicing through the body from the front to the back, yielding a view from the side. Therefore, when the slice thickness is adjusted, it alters the amount of tissue captured in each slice along this depth dimension. Thinner slices will capture less tissue, potentially allowing for greater detail and improved resolution of structures, while thicker slices will encompass a broader volume, potentially averaging out or blurring some details.

In contrast, the X-axis generally refers to the left-right orientation within a single slice, while the Y-axis refers to the superior-inferior orientation. Adjusting slice thickness doesn't affect the measurements or dimensions in these axes directly, as they remain unchanged regarding the positioning of the anatomy displayed in the plane of the slices themselves. The focus is strictly on how much of the tissue is included in images along the Z-axis as the thickness changes.