Noise properties for three weighted Feldkamp algorithms using a 256-detecotor row CT-scanner: case study for hepatic volumetric cine imaging

Eur J Radiol. 2006 Aug;59(2):289-94. doi: 10.1016/j.ejrad.2006.02.007. Epub 2006 Mar 29.

Abstract

In cone-beam geometry, image quality may be degraded or artifacts may occur if the cone angle is substantially wide. This is because a cone-beam scan along a circular orbit does not collect the complete set of data required to make an exact reconstruction of all volumetric data. To increase temporal resolution and thus image quality in cone-beam geometry, Silver proposed the new half-scan algorithm (NHS-FDK), which extends Parker's weighting function (HS-FDK) by utilizing a larger range up to 2pi. Here, we evaluated these algorithms for hepatic contrast-enhanced CT in cine scan mode using a 256-detector row CT. The full-scan (FS-FDK) images show uniform distribution of the image noise and CT-number uniformity. Image noise and CT-number uniformity with HS-FDK and NHS-FDK images follow the initial projection angle. HS-FDK images therefore have more changeable higher intensity (brighter) and a lower intensity (darker) areas than respective FS-FDK and NHS-FDK images. We concluded that, considering the trade-off between image quality and temporal resolution, the NHS-FDK algorithm is useful in volumetric cine imaging for the abdomen.

Publication types

  • Clinical Trial

MeSH terms

  • Aged
  • Algorithms*
  • Artifacts*
  • Carcinoma, Hepatocellular / diagnostic imaging*
  • Contrast Media / administration & dosage
  • Humans
  • Liver Neoplasms / diagnostic imaging*
  • Male
  • Middle Aged
  • Radiographic Image Enhancement / methods*
  • Tomography, X-Ray Computed / classification*
  • Tomography, X-Ray Computed / instrumentation
  • Tomography, X-Ray Computed / methods*

Substances

  • Contrast Media