Improved accuracy and precision of fat-suppressed isotropic 3D T2 mapping MRI of the knee with dictionary fitting and patch-based denoising
Purpose To develop an isotropic three-dimensional (3D) T2 mapping technique for the quantitative assessment of the composition of knee cartilage with high accuracy and precision. Methods A T2-prepared water-selective isotropic 3D gradient-echo pulse sequence was used to generate four images at 3 T....
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Published in | European radiology experimental Vol. 7; no. 1; p. 25 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Vienna
Springer Vienna
22.05.2023
Springer Nature B.V SpringerOpen |
Subjects | |
Online Access | Get full text |
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Summary: | Purpose
To develop an isotropic three-dimensional (3D) T2 mapping technique for the quantitative assessment of the composition of knee cartilage with high accuracy and precision.
Methods
A T2-prepared water-selective isotropic 3D gradient-echo pulse sequence was used to generate four images at 3 T. These were used for three T2 map reconstructions: standard images with an analytical T2 fit (AnT2Fit); standard images with a dictionary-based T2 fit (DictT2Fit); and patch-based-denoised images with a dictionary-based T2 fit (DenDictT2Fit). The accuracy of the three techniques was first optimized in a phantom study against spin-echo imaging, after which knee cartilage T2 values and coefficients of variation (CoV) were assessed in ten subjects in order to establish accuracy and precision
in vivo
. Data given as mean ± standard deviation.
Results
After optimization in the phantom, whole-knee cartilage T2 values of the healthy volunteers were 26.6 ± 1.6 ms (AnT2Fit), 42.8 ± 1.8 ms (DictT2Fit,
p
< 0.001
versus
AnT2Fit), and 40.4 ± 1.7 ms (DenDictT2Fit,
p
= 0.009
versus
DictT2Fit). The whole-knee T2 CoV reduced from 51.5% ± 5.6% to 30.5 ± 2.4 and finally to 13.1 ± 1.3%, respectively (
p
< 0.001 between all). The DictT2Fit improved the data reconstruction time: 48.7 ± 11.3 min (AnT2Fit)
versus
7.3 ± 0.7 min (DictT2Fit,
p
< 0.001). Very small focal lesions were observed in maps generated with DenDictT2Fit.
Conclusions
Improved accuracy and precision for isotropic 3D T2 mapping of knee cartilage were demonstrated by using patch-based image denoising and dictionary-based reconstruction.
Key points
• Dictionary T2 fitting improves the accuracy of three-dimensional (3D) knee T2 mapping.
• Patch-based denoising results in high precision in 3D knee T2 mapping.
• Isotropic 3D knee T2 mapping enables the visualization of small anatomical details. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2509-9280 2509-9280 |
DOI: | 10.1186/s41747-023-00339-8 |