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MRI for assessing abdominal organs iron concentration: A comparative study between the relaxometry methods
Chaotian Luo1, Fei Peng2, Xiaojing Ning2
1Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China; NHC Key Laboratory of Thalassemia Medicine, Nanning, China.
Objective:
To compare magnetic resonance imaging (MRI) commercial 3D quantitative Dixon sequence (qDixon) and 2D multi-gradient recalled echo sequence (GRE) for iron quantification in multiple abdominal organs.
Methods:
1.5T MRI GRE and qDixon data were collected on patients with 211 MR exams from 171 patients (86 males, 85 females; median age: 21 years). Compare the R2* values of liver, pancreas, spleen, and kidneys using Bland-Altman, intraclass correlation coefficients (ICC), concordance correlation coefficients (CCC), and linear regression. Iron overload (IO) diagnostic concordance was assessed using overall agreement and the Kappa coefficient.
Results:
Bland-Altman analysis of liver, pancreas, spleen, and kidney R2* values between GRE and qDixon, resulted in a bias (absolute mean difference) of -11.3 1/s (LoA: 77.7 and -100.3), -11.2 1/s (LoA: 123.9 and -146.3), 5.1 1/s (LoA: 117.3 and -107.1), and 1.9 1/s (LoA: 14.7 and -10.9). The CCCs between GRE and qDixon R2* values for liver, pancreas, spleen, and kidneys were 0.98, 0.94, 0.96, and 0.95, the ICCs were 0.99, 0.95, 0.96, and 0.97, respectively. Linear regression analysis correlating abdominal organs R2* values of GRE and qDixon resulted in a coefficient of determination of 0.96, 0.89, 0.93, and 0.92 (all P < 0.001). The overall agreement was 98.5 %, 94.8 %, 92.6 %, and 90.7 %; the Kappa value was 0.95, 0.89, 0.84, and 0.69 (all P < 0.001).
Conclusion:
The qDixon and GRE showed good agreement and significant positive in measuring R2* values for IO assessment in abdominal organs, with qDixon being an excellent adjunctive diagnostic method.
Insights
The quantitative Dixon (qDixon) sequence and gradient recalled echo (GRE) MRI methods show strong agreement for measuring liver iron levels. qDixon is a reliable tool for assessing iron overload in abdominal organs.
Area of Science:
- Radiology
- Medical Imaging
- Biomedical Engineering
Background:
- Iron overload (IO) is a condition requiring accurate quantification.
- Magnetic Resonance Imaging (MRI) offers non-invasive methods for assessing tissue iron concentration.
- Comparing advanced MRI sequences is crucial for optimizing diagnostic accuracy.
Purpose of the Study:
- To compare the accuracy of a 3D quantitative Dixon (qDixon) sequence against a 2D multi-gradient recalled echo (GRE) sequence for quantifying iron in abdominal organs.
- To evaluate the diagnostic concordance of these two MRI techniques for iron overload assessment.
Main Methods:
- Collected 1.5T MRI data from 211 exams across 171 patients using both GRE and qDixon sequences.
- Analyzed R2* values for liver, pancreas, spleen, and kidneys.
- Employed Bland-Altman analysis, intraclass correlation coefficients (ICC), concordance correlation coefficients (CCC), and linear regression for comparison.
- Assessed iron overload diagnostic agreement using overall agreement and Kappa coefficient.
Main Results:
- High concordance was observed between GRE and qDixon for R2* values across all assessed organs (CCCs ranging from 0.94-0.98, ICCs from 0.95-0.99).
- Linear regression showed strong correlations (coefficient of determination 0.89-0.96) between the two methods for all organs.
- Diagnostic agreement for iron overload was high, with Kappa values ranging from 0.69 to 0.95, indicating substantial to almost perfect agreement.
Conclusions:
- Both qDixon and GRE sequences demonstrate good agreement and positive correlation in measuring R2* values for iron overload assessment in abdominal organs.
- The quantitative Dixon sequence serves as an excellent adjunctive diagnostic method for evaluating iron overload.
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Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table...