Comparison of fan beam, slit-slat and multi-pinhole collimators for molecular breast tomosynthesis

Phys Med Biol. 2018 May 16;63(10):105009. doi: 10.1088/1361-6560/aabfa3.

Abstract

Recently, we proposed and optimized dedicated multi-pinhole molecular breast tomosynthesis (MBT) that images a lightly compressed breast. As MBT may also be performed with other types of collimators, the aim of this paper is to optimize MBT with fan beam and slit-slat collimators and to compare its performance to that of multi-pinhole MBT to arrive at a truly optimized design. Using analytical expressions, we first optimized fan beam and slit-slat collimator parameters to reach maximum sensitivity at a series of given system resolutions. Additionally, we performed full system simulations of a breast phantom containing several tumours for the optimized designs. We found that at equal system resolution the maximum achievable sensitivity increases from pinhole to slit-slat to fan beam collimation with fan beam and slit-slat MBT having on average a 48% and 20% higher sensitivity than multi-pinhole MBT. Furthermore, by inspecting simulated images and applying a tumour-to-background contrast-to-noise (TB-CNR) analysis, we found that slit-slat collimators underperform with respect to the other collimator types. The fan beam collimators obtained a similar TB-CNR as the pinhole collimators, but the optimum was reached at different system resolutions. For fan beam collimators, a 6-8 mm system resolution was optimal in terms of TB-CNR, while with pinhole collimation highest TB-CNR was reached in the 7-10 mm range.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast / diagnostic imaging*
  • Female
  • Gamma Cameras
  • Humans
  • Phantoms, Imaging*
  • Radionuclide Imaging*
  • Signal-To-Noise Ratio
  • Tomography, Emission-Computed, Single-Photon / instrumentation*
  • Tomography, Emission-Computed, Single-Photon / methods*
  • Tomography, Emission-Computed, Single-Photon / standards