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Radiation dose reduction in CT of the brain: can advanced noise filtering compensate for loss of image quality?

Siemund, Roger LU ; Löve, Askell LU ; van Westen, Danielle LU ; Stenberg, Lars LU ; Petersen, C and Björkman-Burtscher, Isabella LU (2012) In Acta radiologica (Stockholm, Sweden : 1987) 53(4). p.468-472
Abstract
Background: Computed tomography (CT) of the brain is performed with high local doses due to high demands on low contrast resolution. Advanced algorithms for noise reduction might be able to preserve critical image information when reducing radiation dose.PurposeTo evaluate the effect of advanced noise filtering on image quality in brain CT acquired with reduced radiation dose.



Material and Methods: Thirty patients referred for non-enhanced CT of the brain were examined with two helical protocols: normal dose (ND, CTDI(vol) 57 mGy) and low dose (LD, CTDI(vol) 40 mGy) implying a 30% radiation dose reduction. Images from the LD examinations were also postprocessed with a noise reduction software with non-linear filters... (More)
Background: Computed tomography (CT) of the brain is performed with high local doses due to high demands on low contrast resolution. Advanced algorithms for noise reduction might be able to preserve critical image information when reducing radiation dose.PurposeTo evaluate the effect of advanced noise filtering on image quality in brain CT acquired with reduced radiation dose.



Material and Methods: Thirty patients referred for non-enhanced CT of the brain were examined with two helical protocols: normal dose (ND, CTDI(vol) 57 mGy) and low dose (LD, CTDI(vol) 40 mGy) implying a 30% radiation dose reduction. Images from the LD examinations were also postprocessed with a noise reduction software with non-linear filters (SharpView CT), creating filtered low dose images (FLD) for each patient. The three image stacks for each patient were presented side by side in randomized order. Five radiologists, blinded for dose level and filtering, ranked these three axial image stacks (ND, LD, FLD) as best to poorest (1 to 3) regarding three image quality criteria. Measurements of mean Hounsfield units (HU) and standard deviation (SD) of the HU were calculated for large region of interest in the centrum semiovale as a measure for noise.



Results: Ranking results in pooled data showed that the advanced noise filtering significantly improved the image quality in FLD as compared to LD images for all tested criteria. No significant differences in image quality were found between ND examinations and FLD. However, there was a notable inter-reader spread of the ranking. SD values were 15% higher for LD as compared to ND and FLD.ConclusionThe advanced noise filtering clearly improves image quality of CT examinations of the brain. This effect can be used to significantly lower radiation dose. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta radiologica (Stockholm, Sweden : 1987)
volume
53
issue
4
pages
468 - 472
publisher
John Wiley & Sons
external identifiers
  • WOS:000304388200017
  • PMID:22509068
  • Scopus:84860616718
ISSN
1600-0455
DOI
10.1258/ar.2012.110629
language
English
LU publication?
yes
id
e5c4e59f-6bb5-4039-acb0-852ea6cf3950 (old id 2519366)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/22509068?dopt=Abstract
date added to LUP
2012-05-06 17:36:27
date last changed
2016-10-13 04:31:23
@misc{e5c4e59f-6bb5-4039-acb0-852ea6cf3950,
  abstract     = {Background: Computed tomography (CT) of the brain is performed with high local doses due to high demands on low contrast resolution. Advanced algorithms for noise reduction might be able to preserve critical image information when reducing radiation dose.PurposeTo evaluate the effect of advanced noise filtering on image quality in brain CT acquired with reduced radiation dose.<br/><br>
<br/><br>
Material and Methods: Thirty patients referred for non-enhanced CT of the brain were examined with two helical protocols: normal dose (ND, CTDI(vol) 57 mGy) and low dose (LD, CTDI(vol) 40 mGy) implying a 30% radiation dose reduction. Images from the LD examinations were also postprocessed with a noise reduction software with non-linear filters (SharpView CT), creating filtered low dose images (FLD) for each patient. The three image stacks for each patient were presented side by side in randomized order. Five radiologists, blinded for dose level and filtering, ranked these three axial image stacks (ND, LD, FLD) as best to poorest (1 to 3) regarding three image quality criteria. Measurements of mean Hounsfield units (HU) and standard deviation (SD) of the HU were calculated for large region of interest in the centrum semiovale as a measure for noise.<br/><br>
<br/><br>
Results: Ranking results in pooled data showed that the advanced noise filtering significantly improved the image quality in FLD as compared to LD images for all tested criteria. No significant differences in image quality were found between ND examinations and FLD. However, there was a notable inter-reader spread of the ranking. SD values were 15% higher for LD as compared to ND and FLD.ConclusionThe advanced noise filtering clearly improves image quality of CT examinations of the brain. This effect can be used to significantly lower radiation dose.},
  author       = {Siemund, Roger and Löve, Askell and van Westen, Danielle and Stenberg, Lars and Petersen, C and Björkman-Burtscher, Isabella},
  issn         = {1600-0455},
  language     = {eng},
  number       = {4},
  pages        = {468--472},
  publisher    = {ARRAY(0x782f230)},
  series       = {Acta radiologica (Stockholm, Sweden : 1987)},
  title        = {Radiation dose reduction in CT of the brain: can advanced noise filtering compensate for loss of image quality?},
  url          = {http://dx.doi.org/10.1258/ar.2012.110629},
  volume       = {53},
  year         = {2012},
}