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Table. 4.

Table. 4.

RED and EAN for DL-DECT images with wide collimation and narrow collimation for Arr2

Material RED EAN


Theoretical value Wide collimation Narrow collimation Theoretical value Wide collimation Narrow collimation




Mean R.D (%) Mean R.D (%) Mean R.D (%) Mean R.D (%)
Lung inhale 1 0.200 0.201 0.5 0.197 −1.5 6.685 5.049 −24.5 6.688 0.0
Lung inhale 2 0.200 0.2 0.209 4.5 5.590 −16.4 6.239 −6.7
Lung exhale 1 0.496 0.531 7.1 0.539 8.7 7.231 7.428 2.7 7.248 0.2
Lung exhale 2 0.530 6.9 0.536 8.1 7.635 5.6 7.347 1.6
Adipose 1 0.949 0.960 1.2 0.956 0.7 6.301 6.220 −1.3 6.263 −0.6
Adipose 2 0.955 0.6 0.954 0.5 6.374 1.2 6.376 1.2
Breast 1 0.976 0.984 0.8 0.984 0.8 6.651 6.735 1.3 6.721 1.1
Breast 2 0.983 0.7 0.982 0.6 7.093 6.7 6.763 1.7
Muscle 1 1.040 1.043 0.3 1.043 0.3 7.249 7.441 2.7 7.391 2.0
Muscle 2 1.044 0.4 1.043 0.3 7.594 4.7 7.329 1.1
Liver 1 1.052 1.053 0.1 1.050 −0.2 7.258 7.343 1.2 7.397 1.9
Liver 2 1.044 −0.8 1.049 0.3 8.174 12.6 7.369 1.5
Trabecular bone 1 1.117 1.093 −2.2 1.094 −2.1 9.833 10.044 2.1 9.774 −0.6
Trabecular bone 2 1.078 −3.5 1.095 −2.0 10.440 6.2 9.754 −0.8

RED, relative electron density; EAN, effective atomic number; DL-DECT, dual-layer dual-energy computed tomography; Arr, arrangement.

R.D indicates the relative difference between theoretical values and the measured values.

Progress in Medical Physics 2021;32:165-71 https://doi.org/10.14316/pmp.2021.32.4.165
© 2021 Progress in Medical Physics