Spatial resolution (CT)
Spatial resolution in CT is the ability to distinguish between object or structures that differ in density.
A high spatial resolution is important for one to discriminate between structures that are located within a small proximity to each other.
Factors affecting CT spatial resolution
- field of view
- as the FOV increases so do the pixel size; resulting in a decrease
- pixel size
- the smaller the pixel size the higher the spatial resolution
- focal spot size
- a larger focal spot will decrease the resolution
- magnification
- increasing will decrease the resolution
- motion of the patient
- pitch
- is inversely related to the resolution, the higher the pitch the less the resolution
- kernel
- edge enhancement kernels will have a higher resolution than soft tissue kernels
- slice thickness
- the larger the slice thickness the lower the resolution
- detector size
- increase in detector size decreases resolution