Spatial resolution

  • Spatial resolution
    • ability of an imaging modality to
    • differentiate two adjacent structures as
    • distinct from each other.
    •  expressed in
      • line pairs per mm (lp mm).
  • CT  scans are limited to a resolution of 1 millimeter, which provides sufficient detail for clinical use
    • Voxel size is an important factor t of image quality.
      • related to both the pixel size and slice thickness.
      • Pixel size is dependent on
        • the field of view and the
        • image matrix.
          • pixel size = FOV/ matrix size
      • matrix size is typically 128x, 256x or 512x.
      • pixel size is typically between 0.5 and 1.5 mm.
      • Increased voxel size results in an
        • increased signal-to-noise ratio
    •  Micro-CT scanners can work at the level of one micron, which is a thousandth of a millimeter, and smaller.
    • Nano-CT is similar to micro-CT and medical CT scanning but at resolutions in nanometers instead of microns or mm
  • smaller focal spot
    • fundamental spatial resolution improves with a
  • When spatial resolution is suboptimal
  • there is blur between the 2 structures