Diego Hernando1,2, Rachel J Cook3,4, Naila Qazi5,6, Colin A Longhurst7, Carol A Diamond8, Scott B Reeder5,9,3,10,11. 1. Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Rm 2474, 1111 Highland Ave, Madison, WI, 53705, USA. dhernando@wisc.edu. 2. Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA. dhernando@wisc.edu. 3. Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA. 4. Department of Medicine, Oregon Health Sciences University, Portland, OR, USA. 5. Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Rm 2474, 1111 Highland Ave, Madison, WI, 53705, USA. 6. Department of Radiology, Avera Medical Group, Yankton, SD, USA. 7. Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA. 8. Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA. 9. Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA. 10. Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA. 11. Emergency Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Abstract
OBJECTIVES: MRI-based R2* mapping may enable reliable and rapid quantification of liver iron concentration (LIC). However, the performance and reproducibility of R2* across acquisition protocols remain unknown. Therefore, the objective of this work was to evaluate the performance and reproducibility of complex confounder-corrected R2* across acquisition protocols, at both 1.5 T and 3.0 T. METHODS: In this prospective study, 40 patients with suspected iron overload and 10 healthy controls were recruited with IRB approval and informed written consent and imaged at both 1.5 T and 3.0 T. For each subject, acquisitions included four different R2* mapping protocols at each field strength, and an FDA-approved R2-based method performed at 1.5 T as a reference for LIC. R2* maps were reconstructed from the complex data acquisitions including correction for noise effects and fat signal. For each subject, field strength, and R2* acquisition, R2* measurements were performed in each of the nine liver Couinaud segments and the spleen. R2* measurements were compared across protocols and field strength (1.5 T and 3.0 T), and R2* was calibrated to LIC for each acquisition and field strength. RESULTS: R2* demonstrated high reproducibility across acquisition protocols (p > 0.05 for 96/108 pairwise comparisons across 2 field strengths and 9 liver segments, ICC > 0.91 for each field strength/segment combination) and high predictive ability (AUC > 0.95 for four clinically relevant LIC thresholds). Calibration of R2* to LIC was LIC = - 0.04 + 2.62 × 10-2 R2* at 1.5 T and LIC = 0.00 + 1.41 × 10-2 R2* at 3.0 T. CONCLUSIONS: Complex confounder-corrected R2* mapping enables LIC quantification with high reproducibility across acquisition protocols, at both 1.5 T and 3.0 T. KEY POINTS: • Confounder-corrected R2* of the liver provides reproducible R2* across acquisition protocols, including different spatial resolutions, echo times, and slice orientations, at both 1.5 T and 3.0 T. • For all acquisition protocols, high correlation with R2-based liver iron concentration (LIC) quantification was observed. • The calibration between confounder-corrected R2* and LIC, at both 1.5 T and 3.0 T, is determined in this study.
OBJECTIVES: MRI-based R2* mapping may enable reliable and rapid quantification of liver iron concentration (LIC). However, the performance and reproducibility of R2* across acquisition protocols remain unknown. Therefore, the objective of this work was to evaluate the performance and reproducibility of complex confounder-corrected R2* across acquisition protocols, at both 1.5 T and 3.0 T. METHODS: In this prospective study, 40 patients with suspected iron overload and 10 healthy controls were recruited with IRB approval and informed written consent and imaged at both 1.5 T and 3.0 T. For each subject, acquisitions included four different R2* mapping protocols at each field strength, and an FDA-approved R2-based method performed at 1.5 T as a reference for LIC. R2* maps were reconstructed from the complex data acquisitions including correction for noise effects and fat signal. For each subject, field strength, and R2* acquisition, R2* measurements were performed in each of the nine liver Couinaud segments and the spleen. R2* measurements were compared across protocols and field strength (1.5 T and 3.0 T), and R2* was calibrated to LIC for each acquisition and field strength. RESULTS: R2* demonstrated high reproducibility across acquisition protocols (p > 0.05 for 96/108 pairwise comparisons across 2 field strengths and 9 liver segments, ICC > 0.91 for each field strength/segment combination) and high predictive ability (AUC > 0.95 for four clinically relevant LIC thresholds). Calibration of R2* to LIC was LIC = - 0.04 + 2.62 × 10-2 R2* at 1.5 T and LIC = 0.00 + 1.41 × 10-2 R2* at 3.0 T. CONCLUSIONS: Complex confounder-corrected R2* mapping enables LIC quantification with high reproducibility across acquisition protocols, at both 1.5 T and 3.0 T. KEY POINTS: • Confounder-corrected R2* of the liver provides reproducible R2* across acquisition protocols, including different spatial resolutions, echo times, and slice orientations, at both 1.5 T and 3.0 T. • For all acquisition protocols, high correlation with R2-based liver iron concentration (LIC) quantification was observed. • The calibration between confounder-corrected R2* and LIC, at both 1.5 T and 3.0 T, is determined in this study.
Entities:
Keywords:
Biomarkers; Iron overload; Liver; Magnetic resonance imaging
Authors: Jose M Alústiza; Agustin Castiella; Maria D De Juan; Jose I Emparanza; Jose Artetxe; Maite Uranga Journal: Eur J Radiol Date: 2006-12-12 Impact factor: 3.528
Authors: G M Brittenham; A R Cohen; C E McLaren; M B Martin; P M Griffith; A W Nienhuis; N S Young; C J Allen; D E Farrell; J W Harris Journal: Am J Hematol Date: 1993-01 Impact factor: 10.047
Authors: Youngwook Kee; Christopher M Sandino; Ali B Syed; Joseph Y Cheng; Ann Shimakawa; Timothy J Colgan; Diego Hernando; Shreyas S Vasanawala Journal: Magn Reson Med Date: 2021-01-11 Impact factor: 4.668