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Variable flip angle 3D ultrashort echo time (UTE) T1 mapping of mouse lung : A repeatability assessment

Alamidi, Daniel F; Smailagic, Amir; Bidar, Abdel W.; Parker, Nicole S.; Olsson, Marita; Hockings, Paul D.; Lagerstrand, Kerstin M and Olsson, Lars E. LU (2018) In Journal of Magnetic Resonance Imaging 48(3). p.846-852
Abstract

Background: Lung T1 is a potential translational biomarker of lung disease. The precision and repeatability of variable flip angle (VFA) T1 mapping using modern 3D ultrashort echo time (UTE) imaging of the whole lung needs to be established before it can be used to assess response to disease and therapy. Purpose: To evaluate the feasibility of regional lung T1 quantification with VFA 3D-UTE and to investigate long- and short-term T1 repeatability in the lungs of naive mice. Study type: Prospective preclinical animal study. Population: Eight naive mice and phantoms. Field strength/Sequence: 3D free-breathing radial UTE (8 μs) at 4.7T. Assessment: VFA 3D-UTE T1 calculations were... (More)

Background: Lung T1 is a potential translational biomarker of lung disease. The precision and repeatability of variable flip angle (VFA) T1 mapping using modern 3D ultrashort echo time (UTE) imaging of the whole lung needs to be established before it can be used to assess response to disease and therapy. Purpose: To evaluate the feasibility of regional lung T1 quantification with VFA 3D-UTE and to investigate long- and short-term T1 repeatability in the lungs of naive mice. Study type: Prospective preclinical animal study. Population: Eight naive mice and phantoms. Field strength/Sequence: 3D free-breathing radial UTE (8 μs) at 4.7T. Assessment: VFA 3D-UTE T1 calculations were validated against T1 values measured with inversion recovery (IR) in phantoms. Lung T1 and proton density (S0) measurements of whole lung and muscle were repeated five times over 1 month in free-breathing naive mice. Two consecutive T1 measurements were performed during one of the imaging sessions. Statistical Tests: Agreement in T1 between VFA 3D-UTE and IR in phantoms was assessed using Bland-Altman and Pearson 's correlation analysis. The T1 repeatability in mice was evaluated using coefficient of variation (CV), repeated-measures analysis of variance (ANOVA), and paired t-test. Results: Good T1 agreement between the VFA 3D-UTE and IR methods was found in phantoms. T1 in lung and muscle showed a 5% and 3% CV (1255±63 msec and 1432±42 msec, respectively, mean±SD) with no changes in T1 or S0 over a month. Consecutive measurements resulted in an increase of 2% in both lung T1 and S0. Data Conclusion: VFA 3D-UTE shows promise as a reliable T1 mapping method that enables full lung coverage, high signal-to-noise ratio (∼25), and spatial resolution (300 μm) in freely breathing animals. The precision of the VFA 3D-UTE method will enable better design and powering of studies.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
3D radial, Biomarker, Longitudinal relaxation time, Lung imaging, Mouse, T mapping
in
Journal of Magnetic Resonance Imaging
volume
48
issue
3
pages
846 - 852
publisher
John Wiley & Sons
external identifiers
  • scopus:85043347103
ISSN
1053-1807
DOI
10.1002/jmri.25999
language
English
LU publication?
yes
id
9fc6ed97-3a44-443b-8af0-5bd4f53854df
date added to LUP
2018-03-23 10:35:53
date last changed
2019-10-15 06:33:57
@article{9fc6ed97-3a44-443b-8af0-5bd4f53854df,
  abstract     = {<p>Background: Lung T<sub>1</sub> is a potential translational biomarker of lung disease. The precision and repeatability of variable flip angle (VFA) T<sub>1</sub> mapping using modern 3D ultrashort echo time (UTE) imaging of the whole lung needs to be established before it can be used to assess response to disease and therapy. Purpose: To evaluate the feasibility of regional lung T<sub>1</sub> quantification with VFA 3D-UTE and to investigate long- and short-term T<sub>1</sub> repeatability in the lungs of naive mice. Study type: Prospective preclinical animal study. Population: Eight naive mice and phantoms. Field strength/Sequence: 3D free-breathing radial UTE (8 μs) at 4.7T. Assessment: VFA 3D-UTE T<sub>1</sub> calculations were validated against T<sub>1</sub> values measured with inversion recovery (IR) in phantoms. Lung T<sub>1</sub> and proton density (S<sub>0</sub>) measurements of whole lung and muscle were repeated five times over 1 month in free-breathing naive mice. Two consecutive T<sub>1</sub> measurements were performed during one of the imaging sessions. Statistical Tests: Agreement in T<sub>1</sub> between VFA 3D-UTE and IR in phantoms was assessed using Bland-Altman and Pearson 's correlation analysis. The T<sub>1</sub> repeatability in mice was evaluated using coefficient of variation (CV), repeated-measures analysis of variance (ANOVA), and paired t-test. Results: Good T<sub>1</sub> agreement between the VFA 3D-UTE and IR methods was found in phantoms. T<sub>1</sub> in lung and muscle showed a 5% and 3% CV (1255±63 msec and 1432±42 msec, respectively, mean±SD) with no changes in T<sub>1</sub> or S<sub>0</sub> over a month. Consecutive measurements resulted in an increase of 2% in both lung T<sub>1</sub> and S<sub>0</sub>. Data Conclusion: VFA 3D-UTE shows promise as a reliable T<sub>1</sub> mapping method that enables full lung coverage, high signal-to-noise ratio (∼25), and spatial resolution (300 μm) in freely breathing animals. The precision of the VFA 3D-UTE method will enable better design and powering of studies.</p>},
  author       = {Alamidi, Daniel F and Smailagic, Amir and Bidar, Abdel W. and Parker, Nicole S. and Olsson, Marita and Hockings, Paul D. and Lagerstrand, Kerstin M and Olsson, Lars E.},
  issn         = {1053-1807},
  keyword      = {3D radial,Biomarker,Longitudinal relaxation time,Lung imaging,Mouse,T mapping},
  language     = {eng},
  number       = {3},
  pages        = {846--852},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Magnetic Resonance Imaging},
  title        = {Variable flip angle 3D ultrashort echo time (UTE) T<sub>1</sub> mapping of mouse lung : A repeatability assessment},
  url          = {http://dx.doi.org/10.1002/jmri.25999},
  volume       = {48},
  year         = {2018},
}