What happens to spatial resolution as slice thickness increases?

As slice thickness increases, spatial resolution decreases. This is because spatial resolution refers to the ability of an imaging system to distinguish between two closely spaced objects. Thinner slices allow for more detailed images since they capture a smaller volume of tissue, leading to better definition of structures. When the slice thickness is increased, the volume of tissue sampled grows, which can blur the distinction between adjacent structures and result in a loss of detail.

In imaging techniques, such as CT or MRI, a thicker slice can encompass more structures within that slice, making it harder to discern their individual outlines and features. Consequently, finer details are lost, and the clarity with which structures can be identified diminishes. This is why an increase in slice thickness is directly correlated with a decrease in spatial resolution.