Multisite, multivendor validation of the accuracy and reproducibility of proton-density fat-fraction quantification at 1.5T and 3T using a fat-water phantom

Abstract

Purpose To evaluate the accuracy and reproducibility of quantitative chemical shift-encoded MRI (CSE-MRI) to quantify proton-density fat-fraction (PDFF) in a fat-water phantom across sites, vendors, field strengths and protocols. Methods Six sites (three vendors: GE/Philips/Siemens) participated in this study. A phantom containing multiple vials with various oil-water suspensions (PDFF:0–100%) was built, shipped to each site and scanned at 1.5T and 3T using two CSE protocols per field strength. Confounder-corrected PDFF maps were reconstructed using a common algorithm. To assess accuracy, PDFF bias and linear regression with the known PDFF were calculated. To assess reproducibility, measurements were compared across sites, vendors, field strengths and protocols using analysis of covariance (ANCOVA), Bland-Altman analysis and the intra-class correlation coefficient (ICC). Results PDFF measurements showed overall absolute bias (across sites, field strengths and protocols)=0.22% with 95% CI:(0.07%,0.38%), and R2>0.995 relative to the known PDFF at each site, field strength and protocol (slopes: 0.96–1.02, intercepts: −0.56%–1.13%). ANCOVA did not show effects of field strength (p=0.36), or protocol (p=0.19). There was a significant effect of vendor (F=25.13,p=1.07×10−10), with bias= −0.37% (Philips) and −1.22% (Siemens) relative to GE. The overall ICC was 0.999. Conclusion CSE-based fat quantification is accurate and reproducible across sites, vendors, field strengths and protocols.

Quantification of renal steatosis in type II diabetes mellitus using dixon‐based MRI

“…The lack of significant difference in the splenic FF supports the notion that slice thickness likely did not contribute to the effect seen for renal FF. Though not directly confirmed in this study, the difference in scanner models also is not expected to impact proton-density FF estimates based on previous multi-vendor, multi-platform reproducibility studies of hepatic steatosis (38,39). Lastly, the observed effect size (i.e.…”

Accurate simultaneous quantification of liver steatosis and iron overload in diffuse liver diseases with MRI

“…Higher susceptibility artifacts on 3 T magnets [39] result in lower thresholds for the maximum iron burden quantification at this filed strength, due to T2*-shortening effect [2,40]. Although the repeatability of our MECSE-MR sequence was not evaluated, similar approaches have been found to have extremely high intra-and inter-examination PDFF estimation repeatability [41,42]. Finally, we did not compare our results of PDFF and R2* quantification against other MRI methods or tools.…”

“…Finally, we did not compare our results of PDFF and R2* quantification against other MRI methods or tools. However, it has been demonstrated that estimation of hepatic PDFF is reproducible across imaging methods, magnetic field strengths, and different vendors [41,42]. Iron-related R2* quantification is also dependent on the magnetic field strength and the quantitative MR protocol [6].…”

Quantification of intrapancreatic fat in type 2 diabetes by MRI

“…A recent phantom study evaluated the reproducibility of MRI fat quantification technique between research centres, MR scanner vendors, field strengths, and acquisition protocols [49] emphasizing the importance of standardized image analysis technique for precise comparison. However, use of a phantom does not reflect the complexities introduced by variable inclusion of visceral fat and fluid filled intra-organ ducts.…”