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Knee dGEMRIC at 7 T : Comparison against 1.5 T and evaluation of T1-mapping methods

Peterson, Pernilla LU ; Tiderius, Carl Johan LU ; Olsson, Emma LU ; Lundin, Björn LU ; Olsson, Lars E. LU and Svensson, Jonas LU (2018) In BMC Musculoskeletal Disorders 19(1).
Abstract

Background: dGEMRIC (delayed Gadolinium Enhanced Magnetic Resonance Image of Cartilage) is a well-established technique for cartilage quality assessment in osteoarthritis at clinical field strengths. The method is robust, but requires injection of contrast agent and a cumbersome examination procedure. New non-contrast-agent-based techniques for cartilage quality assessment are currently being developed at 7 T. However, dGEMRIC remains an important reference technique during this development. The aim of this work was to compare T1 mapping for dGEMRIC at 7 T and 1.5 T, and to evaluate three T1-mapping methods at 7 T. Methods: The knee of 10 healthy volunteers and 9 patients with early signs of cartilage degradation... (More)

Background: dGEMRIC (delayed Gadolinium Enhanced Magnetic Resonance Image of Cartilage) is a well-established technique for cartilage quality assessment in osteoarthritis at clinical field strengths. The method is robust, but requires injection of contrast agent and a cumbersome examination procedure. New non-contrast-agent-based techniques for cartilage quality assessment are currently being developed at 7 T. However, dGEMRIC remains an important reference technique during this development. The aim of this work was to compare T1 mapping for dGEMRIC at 7 T and 1.5 T, and to evaluate three T1-mapping methods at 7 T. Methods: The knee of 10 healthy volunteers and 9 patients with early signs of cartilage degradation were examined at 1.5 T and 7 T after a single (one) contrast agent injection (Gd-(DTPA)2-). Inversion recovery (IR) sequences were acquired at both field strengths, and at 7 T variable flip angle (VFA) and Look-Locker (LL) sequences were additionally acquired. T1 maps were calculated and average T1 values were estimated within superficial and deep regions-of-interest (ROIs) in the lateral and medial condyles, respectively. Results: T1 values were 1.8 (1.4-2.3) times longer at 7 T. A strong correlation was detected between 1.5 T and 7 T T1 values (r = 0.80). For IR, an additional inversion time was required to avoid underestimation (bias±limits of agreement - 127 ± 234 ms) due to the longer T1 values at 7 T. Out of the two 3D sequences tested, LL resulted in more accurate and precise T1 estimation compared to VFA (average bias±limits of agreement LL: 12 ± 202 ms compared to VFA: 25 ± 622 ms). For both, B1 correction improved agreement to IR. Conclusion: With an adapted sampling scheme, dGEMRIC T1 mapping is feasible at 7 T and correlates well to 1.5 T. If 3D is to be used for T1 mapping of the knee at 7 T, LL is preferred and VFA is not recommended. For VFA and LL, B1 correction is necessary for accurate T1 estimation.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
7 T, Cartilage, dGEMRIC, Inversion recovery, Look-locker, Variable flip angle
in
BMC Musculoskeletal Disorders
volume
19
issue
1
article number
149
publisher
BioMed Central
external identifiers
  • pmid:29769051
  • scopus:85047206637
ISSN
1471-2474
DOI
10.1186/s12891-018-2071-1
language
English
LU publication?
yes
id
0e93449b-a92b-406b-9265-19d08a3432fb
date added to LUP
2018-06-01 13:41:53
date last changed
2020-02-12 09:29:42
@article{0e93449b-a92b-406b-9265-19d08a3432fb,
  abstract     = {<p>Background: dGEMRIC (delayed Gadolinium Enhanced Magnetic Resonance Image of Cartilage) is a well-established technique for cartilage quality assessment in osteoarthritis at clinical field strengths. The method is robust, but requires injection of contrast agent and a cumbersome examination procedure. New non-contrast-agent-based techniques for cartilage quality assessment are currently being developed at 7 T. However, dGEMRIC remains an important reference technique during this development. The aim of this work was to compare T<sub>1</sub> mapping for dGEMRIC at 7 T and 1.5 T, and to evaluate three T<sub>1</sub>-mapping methods at 7 T. Methods: The knee of 10 healthy volunteers and 9 patients with early signs of cartilage degradation were examined at 1.5 T and 7 T after a single (one) contrast agent injection (Gd-(DTPA)<sup>2-</sup>). Inversion recovery (IR) sequences were acquired at both field strengths, and at 7 T variable flip angle (VFA) and Look-Locker (LL) sequences were additionally acquired. T<sub>1</sub> maps were calculated and average T<sub>1</sub> values were estimated within superficial and deep regions-of-interest (ROIs) in the lateral and medial condyles, respectively. Results: T<sub>1</sub> values were 1.8 (1.4-2.3) times longer at 7 T. A strong correlation was detected between 1.5 T and 7 T T<sub>1</sub> values (r = 0.80). For IR, an additional inversion time was required to avoid underestimation (bias±limits of agreement - 127 ± 234 ms) due to the longer T<sub>1</sub> values at 7 T. Out of the two 3D sequences tested, LL resulted in more accurate and precise T<sub>1</sub> estimation compared to VFA (average bias±limits of agreement LL: 12 ± 202 ms compared to VFA: 25 ± 622 ms). For both, B<sub>1</sub> correction improved agreement to IR. Conclusion: With an adapted sampling scheme, dGEMRIC T<sub>1</sub> mapping is feasible at 7 T and correlates well to 1.5 T. If 3D is to be used for T<sub>1</sub> mapping of the knee at 7 T, LL is preferred and VFA is not recommended. For VFA and LL, B<sub>1</sub> correction is necessary for accurate T<sub>1</sub> estimation.</p>},
  author       = {Peterson, Pernilla and Tiderius, Carl Johan and Olsson, Emma and Lundin, Björn and Olsson, Lars E. and Svensson, Jonas},
  issn         = {1471-2474},
  language     = {eng},
  month        = {05},
  number       = {1},
  publisher    = {BioMed Central},
  series       = {BMC Musculoskeletal Disorders},
  title        = {Knee dGEMRIC at 7 T : Comparison against 1.5 T and evaluation of T<sub>1</sub>-mapping methods},
  url          = {http://dx.doi.org/10.1186/s12891-018-2071-1},
  doi          = {10.1186/s12891-018-2071-1},
  volume       = {19},
  year         = {2018},
}