eprintid: 1535930 rev_number: 28 eprint_status: archive userid: 608 dir: disk0/01/53/59/30 datestamp: 2017-01-14 23:12:40 lastmod: 2020-02-12 16:00:23 status_changed: 2017-01-17 09:24:40 type: article metadata_visibility: show creators_name: Zhao, C creators_name: Vassiljev, N creators_name: Konstantinidis, A creators_name: Speller, R creators_name: Kanicki, J title: Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis ispublished: pub divisions: UCL divisions: A01 divisions: B04 divisions: C05 divisions: F42 keywords: CMOS active pixel sensor, cascaded system analysis, detective quantum efficiency, digital breast tomosynthesis, pixelated scintillator, three-dimensional, x-ray detector note: © Copyright 2017 IOP Publishing abstract: High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 ��m pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30��. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g. ��30��) improves the low spatial frequency (below 5 mm-1) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 ��m pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared. date: 2017-03-07 date_type: published official_url: http://dx.doi.org/10.1088/1361-6560/aa586c oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1201655 doi: 10.1088/1361-6560/aa586c lyricists_name: Speller, Robert lyricists_id: RDSPE08 actors_name: Bracey, Alan actors_id: ABBRA90 actors_role: owner full_text_status: public publication: Physics in Medicine & Biology volume: 62 number: 5 pagerange: 1994-2017 event_location: England issn: 1361-6560 citation: Zhao, C; Vassiljev, N; Konstantinidis, A; Speller, R; Kanicki, J; (2017) Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis. Physics in Medicine & Biology , 62 (5) pp. 1994-2017. 10.1088/1361-6560/aa586c <https://doi.org/10.1088/1361-6560%2Faa586c>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1535930/1/Zhao%2Bet%2Bal_2017_Phys._Med._Biol._10.1088_1361-6560_aa586c.pdf