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Published on: September 7, 2018
Quantification of the Proton Density Fat Fraction and Iron Content: A Comparative Study Between 3.0 T and 5.0 T MRI
Yali Li1, Dan Jin1, Suwei Liu1
1Department of Radiology, Peking University Third Hospital, Beijing, China.
Background:
Proton density fat fraction (PDFF) and R2* are noninvasive MRI biomarkers for quantifying fat and iron in abdominal organs. While 3.0 T MRI is widely used clinically, 5.0 T may offer improved accuracy and reliability. With the increasing availability of 5.0 T, assessing its feasibility and utility for quantifying PDFF and R2* in abdominal organs is needed.
Purpose:
To determine the agreement of the PDFF and R2* in the liver, pancreas, kidney, and paraspinal muscle at 2 different field strengths.
Study Type:
Prospective.
Population:
A total of 127 participants, including 60 healthy volunteers and 67 with metabolic dysfunction-associated steatotic liver disease (100 women and 27 men, 52 ± 9 years old).
Field Strength/Sequence:
3.0 T and 5.0 T; Chemical shift-encoded multi-echo gradient echo sequence.
Assessment:
PDFF and R2* values in the liver, pancreas, kidney, and paraspinal muscle were measured by three observers to evaluate the interobserver and interfield agreement using two 3.0 T scanners (scanner 1 and scanner 2) and one 5.0 T scanner.
Statistical Tests:
Linear regression, Bland-Altman analyses, and intraclass correlation coefficients (ICCs). The p-value < 0.05 indicated statistically significant.
Results:
PDFF and R2* at 5.0 T were strongly correlated with those at two 3.0 T scanners for all organs (R 2 = 0.905-0.998 for PDFF; 0.831-0.991 for R2*), indicating high interfield ICCs (0.892-0.993 for PDFF; 0.910-0.981 for R2*). Comparisons between 5.0 T and two 3.0 T scanners showed good interfield agreement for PDFF (mean bias, -0.57% to 0.03%) while a higher bias for R2* (mean bias, -16.53 to -2.64 s-1, 95% LoA, -34.28 to 1.21 s-1) at 5.0 T compared to the comparison between 3T scanners.
Data Conclusion:
5.0 T revealed high interfield agreement between the PDFF and R2* with 3.0 T, which could provide reliable quantification of fat and iron contents in abdominal organs.
Evidence Level:
2.
Technical Efficacy:
Stage 2.
Insights
Higher magnetic field strength MRI (5.0 T) shows excellent agreement with standard 3.0 T for quantifying liver fat (PDFF) and iron (R2*), offering reliable abdominal organ analysis.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Biomarker Quantification
- Medical Imaging Physics
Background:
- Proton density fat fraction (PDFF) and R2* are established noninvasive MRI biomarkers for assessing fat and iron in abdominal organs.
- Clinical standard 3.0 Tesla (T) MRI is widely used, but higher field strengths like 5.0 T may enhance accuracy and reliability.
- The increasing availability of 5.0 T MRI necessitates an evaluation of its utility for quantifying PDFF and R2* in abdominal organs.
Purpose of the Study:
- To assess the agreement of proton density fat fraction (PDFF) and R2* measurements in the liver, pancreas, kidney, and paraspinal muscle between 3.0 T and 5.0 T MRI scanners.
- To determine the feasibility and reliability of 5.0 T MRI for abdominal organ biomarker quantification.
Main Methods:
- Prospective study involving 127 participants (60 healthy, 67 with metabolic dysfunction-associated steatotic liver disease).
- MRI scans were performed using a chemical shift-encoded multi-echo gradient echo sequence at both 3.0 T (two scanners) and 5.0 T.
- Quantitative analysis included linear regression, Bland-Altman analyses, and intraclass correlation coefficients (ICCs) to evaluate interobserver and interfield agreement.
Main Results:
- Strong correlations (R² = 0.905–0.998 for PDFF, 0.831–0.991 for R2*) were observed between 5.0 T and 3.0 T measurements across all assessed organs.
- High interfield intraclass correlation coefficients (ICCs) demonstrated excellent agreement (0.892–0.993 for PDFF, 0.910–0.981 for R2*).
- While PDFF showed good interfield agreement with minimal bias, R2* exhibited higher bias at 5.0 T compared to 3.0 T comparisons.
Conclusions:
- 5.0 T MRI demonstrates high interfield agreement with 3.0 T MRI for both PDFF and R2* quantification in abdominal organs.
- These findings suggest that 5.0 T MRI can reliably quantify fat and iron content in abdominal organs, potentially offering improved accuracy.
- The study supports the clinical utility of 5.0 T MRI for noninvasive assessment of metabolic and iron-related conditions.

