Skip to main content

Table 2 Main characteristics of the commercial 3D iterative reconstruction algorithms used in the study

From: Quantitative capabilities of four state-of-the-art SPECT-CT cameras

Name Type Corrections Noise regularization Manufacturer default number of
   Attenuation Scatter Resolution   Subsets Iterations
General Electric Evolution for Bone MAPEM From CT data, bilinear conversion of HU into attenuation coefficients at 140 keV Jaszczak’s dual energy window method with 115 to 125 keV scatter window Matrix rotation One-step late method with green prior and median root prior at last iteration 10 2
Row convolution with spatial resolution kernel stored in look-up table
Philips Astonish OSEM From CT data, HU segmentation using a step-like law, bilinear conversion of HU into attenuation coefficients at 100 keV, scaling to 140 keV ESSE method Convolution with spatial response function Proprietary filtering (Hanning) of acquired projections and computed projections by forward-projection 15 2
Siemens Flash 3D OSEM From CT data, bilinear conversion of HU into attenuation coefficients at 140 keV Modified triple energy window method with 108.5 to 129.5 keV scatter window Matrix rotation Gaussian post-filter (6-mm FWHM default value) 4 12
Gaussian diffusion method with slabs
  1. 3D, three-dimensional; CT, computed tomography; ESSE, effective source scatter estimation; FWHM, full width at half maximum; HU, Hounsfield units; MAPEM, maximum a posteriori expectation maximization; OSEM, ordered subset expectation maximization.