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Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine

Alshamari, Muhammed; Geijer, Mats LU ; Norrman, Eva; Lidén, Mats; Krauss, Wolfgang; Jendeberg, Johan; Magnuson, Anders and Geijer, Håkan (2017) In Acta radiologica (Stockholm, Sweden : 1987) 58(6). p.702-709
Abstract

Background Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality. Purpose To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose. Material and Methods Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images... (More)

Background Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality. Purpose To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose. Material and Methods Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed. Results There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR. Conclusion Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.

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organization
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type
Contribution to journal
publication status
published
subject
keywords
Journal Article
in
Acta radiologica (Stockholm, Sweden : 1987)
volume
58
issue
6
pages
702 - 709
publisher
John Wiley & Sons
external identifiers
  • scopus:85019010032
  • wos:000399995700011
ISSN
1600-0455
DOI
10.1177/0284185116669870
language
English
LU publication?
yes
id
9a4d38e5-e25b-48ae-9198-d162fc7f8acb
date added to LUP
2017-02-21 12:45:13
date last changed
2018-01-07 11:51:36
@article{9a4d38e5-e25b-48ae-9198-d162fc7f8acb,
  abstract     = {<p>Background Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality. Purpose To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose. Material and Methods Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed. Results There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR. Conclusion Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.</p>},
  author       = {Alshamari, Muhammed and Geijer, Mats and Norrman, Eva and Lidén, Mats and Krauss, Wolfgang and Jendeberg, Johan and Magnuson, Anders and Geijer, Håkan},
  issn         = {1600-0455},
  keyword      = {Journal Article},
  language     = {eng},
  number       = {6},
  pages        = {702--709},
  publisher    = {John Wiley & Sons},
  series       = {Acta radiologica (Stockholm, Sweden : 1987)},
  title        = {Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine},
  url          = {http://dx.doi.org/10.1177/0284185116669870},
  volume       = {58},
  year         = {2017},
}