Manually adjusted versus vendor-preset definition of metabolite boundaries impact on proton metabolite ratios
Petrou, Myria ; Sundgren, Pia C LU
; Pang, Yuxi
; Rohrer, Suzan
; Foerster, Bradley
and Chenevert, Thomas L
(2007)
In Academic Radiology
14(3).
p.3-340
- Abstract
RATIONALE AND OBJECTIVES: Metabolite peak boundary definition is an important postprocessing step in proton magnetic resonance spectroscopy (1H-MRS). We compare metabolite ratios calculated using three different postprocessing strategies: software-rendered default peak boundaries, manually adjusted peak boundaries and a curve-fitting program. The first two of these methods are commercially available.
MATERIALS AND METHODS: A total of 42 spectra acquired on a 1.5-T MR unit using two-dimensional chemical shift proton MR spectroscopy (TR/TE = 1500/144 ms) were analyzed. Choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) relative concentrations were derived and the following metabolite ratios were calculated: Cho/Cr, Cho/NAA,... (More)
RATIONALE AND OBJECTIVES: Metabolite peak boundary definition is an important postprocessing step in proton magnetic resonance spectroscopy (1H-MRS). We compare metabolite ratios calculated using three different postprocessing strategies: software-rendered default peak boundaries, manually adjusted peak boundaries and a curve-fitting program. The first two of these methods are commercially available.
MATERIALS AND METHODS: A total of 42 spectra acquired on a 1.5-T MR unit using two-dimensional chemical shift proton MR spectroscopy (TR/TE = 1500/144 ms) were analyzed. Choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) relative concentrations were derived and the following metabolite ratios were calculated: Cho/Cr, Cho/NAA, and NAA/Cr. Metabolite concentrations/ratios were calculated using (a) default peak boundaries rendered by commercially available, postprocessing software (Functool 2000, version 2.6.0); (b) manually adjusted peak boundaries by an experienced spectroscopist, using an option offered by the same commercially available software; and (c) an offline in-house curve-fitting program. Measurements obtained with method (c) were considered as the "gold standard." Paired t-tests comparing default and adjusted metabolite ratios, as well as default and adjusted ratios with their respective curve-fit values were used for statistical analysis.
RESULTS: Significant differences between default and manually adjusted values were found for Cho/Cr ratios <1.5 and for all Cho/NAA ratios. For Cho/Cr ratios <1.5, significant differences between default and curve-fit values were present; this was not the case when comparing manually adjusted and curve-fit values. Default and manually adjusted Cho/NAA ratios were significantly higher than corresponding curve-fit ratios. Manually adjusted values were, however, closer to the curve-fit values. No significant differences were noted between default and adjusted NAA/Cr values; default and manually adjusted ratios were significantly lower than curve-fit ratios.
CONCLUSION: There can be significant differences in metabolite ratios calculated using default and manually adjusted peak limits in proton MR spectroscopy. Furthermore, Cho/Cr and NAA/Cho adjusted metabolite ratios are closer to curve-fit values, which are considered the most accurate of the three.
(Less)
- author
- Petrou, Myria
; Sundgren, Pia C
LU
; Pang, Yuxi
; Rohrer, Suzan
; Foerster, Bradley
and Chenevert, Thomas L
- publishing date
- 2007-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Adolescent, Adult, Aspartic Acid, Brain Chemistry, Child, Chlorine, Creatine, Female, Humans, Magnetic Resonance Spectroscopy, Male, Middle Aged, Protons, Software
- in
- Academic Radiology
- volume
- 14
- issue
- 3
- pages
- 4 pages
- publisher
- Elsevier
- external identifiers
-
- pmid:17307667
- scopus:33847361811
- ISSN
- 1076-6332
- DOI
- 10.1016/j.acra.2006.12.011
- language
- English
- LU publication?
- no
- id
- 9f4dff45-4907-4533-a1eb-bdcab7813589
- date added to LUP
- 2016-04-20 13:16:52
- date last changed
- 2024-01-04 02:30:55
@article{9f4dff45-4907-4533-a1eb-bdcab7813589,
abstract = {{<p>RATIONALE AND OBJECTIVES: Metabolite peak boundary definition is an important postprocessing step in proton magnetic resonance spectroscopy (1H-MRS). We compare metabolite ratios calculated using three different postprocessing strategies: software-rendered default peak boundaries, manually adjusted peak boundaries and a curve-fitting program. The first two of these methods are commercially available.</p><p>MATERIALS AND METHODS: A total of 42 spectra acquired on a 1.5-T MR unit using two-dimensional chemical shift proton MR spectroscopy (TR/TE = 1500/144 ms) were analyzed. Choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) relative concentrations were derived and the following metabolite ratios were calculated: Cho/Cr, Cho/NAA, and NAA/Cr. Metabolite concentrations/ratios were calculated using (a) default peak boundaries rendered by commercially available, postprocessing software (Functool 2000, version 2.6.0); (b) manually adjusted peak boundaries by an experienced spectroscopist, using an option offered by the same commercially available software; and (c) an offline in-house curve-fitting program. Measurements obtained with method (c) were considered as the "gold standard." Paired t-tests comparing default and adjusted metabolite ratios, as well as default and adjusted ratios with their respective curve-fit values were used for statistical analysis.</p><p>RESULTS: Significant differences between default and manually adjusted values were found for Cho/Cr ratios <1.5 and for all Cho/NAA ratios. For Cho/Cr ratios <1.5, significant differences between default and curve-fit values were present; this was not the case when comparing manually adjusted and curve-fit values. Default and manually adjusted Cho/NAA ratios were significantly higher than corresponding curve-fit ratios. Manually adjusted values were, however, closer to the curve-fit values. No significant differences were noted between default and adjusted NAA/Cr values; default and manually adjusted ratios were significantly lower than curve-fit ratios.</p><p>CONCLUSION: There can be significant differences in metabolite ratios calculated using default and manually adjusted peak limits in proton MR spectroscopy. Furthermore, Cho/Cr and NAA/Cho adjusted metabolite ratios are closer to curve-fit values, which are considered the most accurate of the three.</p>}},
author = {{Petrou, Myria and Sundgren, Pia C and Pang, Yuxi and Rohrer, Suzan and Foerster, Bradley and Chenevert, Thomas L}},
issn = {{1076-6332}},
keywords = {{Adolescent; Adult; Aspartic Acid; Brain Chemistry; Child; Chlorine; Creatine; Female; Humans; Magnetic Resonance Spectroscopy; Male; Middle Aged; Protons; Software}},
language = {{eng}},
number = {{3}},
pages = {{3--340}},
publisher = {{Elsevier}},
series = {{Academic Radiology}},
title = {{Manually adjusted versus vendor-preset definition of metabolite boundaries impact on proton metabolite ratios}},
url = {{http://dx.doi.org/10.1016/j.acra.2006.12.011}},
doi = {{10.1016/j.acra.2006.12.011}},
volume = {{14}},
year = {{2007}},
}