LitCovid-sentences  

PMC:7473770 / 48985-51160 JSONTXT 6 Projects

Annnotations TAB TSV DIC JSON TextAE

Id Subject Object Predicate Lexical cue
T406 0-10 Sentence denotes Appendix 2
T407 11-21 Sentence denotes Resolution
T408 22-153 Sentence denotes Resolution estimates are challenging for tissue reconstructions due to the absence of sharp edges or features of well defined size.
T409 154-224 Sentence denotes Here, we follow the approach known as Fourier-shell correlation (FSC).
T410 225-388 Sentence denotes Accordingly, an upper bound for the resolution is be obtained in the following way: the CT scan is split into two, and from each half a 3D volume is reconstructed.
T411 389-568 Sentence denotes After registry, that is, mutual alignment of the volumes, the correlation between the two independent reconstructions in Fourier space is plotted as function of spatial frequency.
T412 569-724 Sentence denotes This correlation must not necessarily reflect the pure system resolution, but instead the range of spatial frequencies over which the results are reliable.
T413 725-849 Sentence denotes As such it is not only affected by the system resolution but also by the sample contrast and the noise of the specific scan.
T414 850-1022 Sentence denotes Further, it represents an average over all structures, not taking into account that features with stronger/weaker contrast can correspondingly show higher/lower resolution.
T415 1023-1114 Sentence denotes Here the Fourier operation for FSC was implemented with a Kaiser-Bessel window of 7 pixels.
T416 1115-1260 Sentence denotes For the parallel-beam data, a central volume of 650 × 650 × 650 voxels was correlated, for the cone-beam data a volume of 685 × 680 × 250 voxels.
T417 1261-1395 Sentence denotes These sub-volumes were selected to obtain the average values for the tissue while minimizing contributions from paraffin-filled holes.
T418 1396-1452 Sentence denotes The correlation curves are shown in Appendix 2—figure 1.
T419 1453-1576 Sentence denotes The intersection of the curve with the half-bit threshold yields the resolution estimate, indicated with dashed black line.
T420 1577-1721 Sentence denotes Correspondingly, a half-period resolution of 0.71⁢μ⁢m and 0.39⁢μ⁢m (or better) is obtained for the parallel and cone beam dataset, respectively.
T421 1722-1932 Sentence denotes However, since the splitted dataset resulted in only 721 angles for the reconstruction, i.e. the resolution estimate is severely affected by under-sampling artifacts, and hence can only serve as an upper bound.
T422 1933-1978 Sentence denotes Appendix 2—figure 1 illustrates the analysis.
T423 1979-1999 Sentence denotes Appendix 2—figure 1.
T424 2001-2065 Sentence denotes Quantification of the 3D-resolution for the example of sample V.
T425 2066-2175 Sentence denotes FSC analysis was carried out for two independent reconstructions, each from half the projections of the scan.