Characterization of the effects of the FineView algorithm for full field digital mammography

Abstract

The aim of this study was to characterize the effect of an image processing algorithm (FineView) on both quantitative image quality parameters and the threshold contrast detail response of the GE Senographe DS full-field digital mammography system. The system was characterized using signal transfer property, pre-sampling modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE) of the system. An algorithmic modulation transfer function (MTF(a)) was calculated from images acquired at a reduced detector air kerma (DAK) and with the FineView algorithm enabled. Two sets of beam conditions were used: Mo/Mo/28 kV and Rh/Rh/29 kV, both with 2 mm added Al filtration at the x-ray tube. Images were acquired with and without FineView at four DAK levels from 14 to 378 µGy. The threshold contrast detail response was assessed using the CDMAM contrast-detail test object which was imaged under standard clinical conditions with and without FineView at three DAK levels from 24 to 243 µGy. The images were scored by both human observers and by automated scoring software. Results indicated an improvement of up to 125% at 5 mm⁻¹ in MTF(a) when FineView was activated, particularly at high DAK levels. A corresponding increase of up to 425% at 5 mm⁻¹ was also seen in the NNPS, again with the same DAK dependence. FineView did not influence DQE, an indication that the signal to noise ratio transfer of the system remained unchanged. FineView did not affect the threshold contrast detectability of the system, a result that is consistent with the DQE results.

Characterization of on-site digital mammography systems: Direct versus indirect conversion detectors

“…We note that the MTF at a very low exposure underestimates the MTF without the FineView option. Our MTF measurements agree well with the literature results [34].…”

“…This figure clearly shows that the FineView option significantly increases the NNPS. Our NNPS measurement seems to be in agreement with the results from the literature [34].…”

“…In other words, the MTF is enhanced with increasing exposure. Figure 7(a) compares the MTF measured at 55 mR with the results reported in the literature [34]. The MTF increases with increasing exposure.…”

“…The effect of the MTF of system A on the NNPS performance is shown in Fig. 7(b), which compares the NNPS of system A with the results from the literature [34]. This figure clearly shows that the FineView option significantly increases the NNPS.…”

“…Without any image processing enhancement of the sharpness as shown in the esf(x) measurement results, the MTF performance of system A, as measured in this study, could not be achieved. From the literature [32][33][34], we learned that system A comes with an image processing algorithm called FineView that applies a Wiener filter, W , to the Fourier transform of an output image to produce an estimate of the Fourier transform of the restored output image. The Wiener filter is described as follows [33]:…”