PMID- 36329118
OWN - NLM
STAT- MEDLINE
DCOM- 20221107
LR  - 20230104
IS  - 2045-2322 (Electronic)
IS  - 2045-2322 (Linking)
VI  - 12
IP  - 1
DP  - 2022 Nov 3
TI  - Imaging a microfocus X-ray focal spot with a thin coded aperture.
PG  - 18635
LID - 10.1038/s41598-022-23338-y [doi]
LID - 18635
AB  - Imaging of the focal spot size in X-ray generators can be achieved by means of a 
      pinhole in a highly attenuating material, such as gold. For microfocus generators 
      with spot sizes of only around 10 microns or less, the material must be very thin 
      to avoid an impractical aspect ratio. With a 90 kV source, only 11% attenuation 
      is attained with 5 microm gold. For a pinhole that is smaller than the focal spot, 
      the signal-to-noise ratio (SNR) may be less than 1. To image the focal spot of a 
      medical X-ray generator, a coded aperture has been used previously to reduce the 
      exposure time required, however the same technique does not appear to have been 
      used to increase the SNR when the attenuation is very low. Such a method is used 
      here, using a no-two-holes-touching variation of a modified uniformly redundant 
      array (MURA). In a prototype sample, with only 5 microm gold having 2.75 microm holes, 
      the focal spot of a microfocus X-ray generator used in a micro-CT system could be 
      clearly visualised and quantified. Directionality of the aberrations made 
      focussing of the X-ray spot more intuitive and reduced the time required to 
      obtain an optimal, quantifiable focus.
CI  - (c) 2022. The Author(s).
FAU - Davis, Graham R
AU  - Davis GR
AD  - Institute of Dentistry, Queen Mary University of London, London, E1 4NS, UK. 
      g.r.davis@qmul.ac.uk.
FAU - Beckenbach, Thomas
AU  - Beckenbach T
AD  - Microworks GmbH, Schnetzlerstr. 9, 76137, Karlsruhe, Germany.
FAU - Meyer, Pascal
AU  - Meyer P
AD  - Institute of Microstructure Technology, Karlsruhe Institute of Technology, 
      Hermann-Von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
LA  - eng
PT  - Journal Article
DEP - 20221103
PL  - England
TA  - Sci Rep
JT  - Scientific reports
JID - 101563288
RN  - 7440-57-5 (Gold)
SB  - IM
MH  - X-Rays
MH  - Radiography
MH  - Phantoms, Imaging
MH  - Signal-To-Noise Ratio
MH  - *Gold
PMC - PMC9633642
COIS- T.B. is an employee of Microworks GmbH, Karlsruhe, Germany. The remaining authors 
      declare no competing interests.
EDAT- 2022/11/05 06:00
MHDA- 2022/11/08 06:00
PMCR- 2022/11/03
CRDT- 2022/11/04 00:27
PHST- 2022/08/30 00:00 [received]
PHST- 2022/10/29 00:00 [accepted]
PHST- 2022/11/04 00:27 [entrez]
PHST- 2022/11/05 06:00 [pubmed]
PHST- 2022/11/08 06:00 [medline]
PHST- 2022/11/03 00:00 [pmc-release]
AID - 10.1038/s41598-022-23338-y [pii]
AID - 23338 [pii]
AID - 10.1038/s41598-022-23338-y [doi]
PST - epublish
SO  - Sci Rep. 2022 Nov 3;12(1):18635. doi: 10.1038/s41598-022-23338-y.