TABLE 1.
Intra‐class coefficients of FW, PSMD, and WMH measures between sites (inter‐rater reliability study), sessions (test–retest repeatability study) and scanners (inter‐scanner reproducibility study)
| FW | PSMD | WMH | ||
|---|---|---|---|---|
| Inter‐rater | UCD‐UNM | 1 ([1; 1], P < .001) | 0.906 ([0.732; 0.965], P < .001) | 0.988 ([0.963; 0.996], P < .001) |
| UCD‐UTHSCSA | 0.993 ([0.933; 0.998], P < .001) | 0.991 ([0.977; 0.997], P < .001) | 0.944 ([0.863; 0.977], P < .001) | |
| UCD‐RUSH | 0.998 ([0.981; 1], P < .001) | 0.999 ([0.998; 1], P < .001) | 0.987 ([0.958; 0.995], P < .001) | |
| UCD‐USC | 0.999 ([0.996; 1], P < .001) | 0.907 ([0.709; 0.967], P < .001) | 0.989 ([0.97; 0.996], P < .001) | |
| UCD‐UKY | 1 ([1; 1], P < .001) | 0.908 ([0.746; 0.965], P < .001) | 0.989 ([0.968; 0.996], P < .001) | |
| UNM‐UTHSCSA | 0.992 ([0.932; 0.998], P < .001) | 0.914 ([0.735; 0.969], P < .001) | 0.979 ([0.949; 0.992], P < .001) | |
| UNM‐RUSH | 0.999 ([0.984; 1], P < .001) | 0.905 ([0.729; 0.965], P < .001) | 0.967 ([0.919; 0.987], P < .001) | |
| UNM‐USC | 0.999 ([0.994; 1], P < .001) | 0.992 ([0.981; 0.997], P < .001) | 1 ([0.999; 1], P < .001) | |
| UNM‐UKY | 1 ([1; 1], P < .001) | 0.998 ([0.995; 0.999], P < .001) | 0.999 ([0.997; 1], P < .001) | |
| UTHSCSA‐RUSH | 0.986 ([0.804; 0.997], P < .001) | 0.993 ([0.982; 0.997], P < .001) | 1 ([0.999; 1], P < .001) | |
| UTHSCSA‐USC | 0.994 ([0.977; 0.998], P < .001) | 0.914 ([0.705; 0.97], P < .001) | 0.966 ([0.918; 0.986], P < .001) | |
| UTHSCSA‐UKY | 0.992 ([0.941; 0.998], P < .001) | 0.914 ([0.75; 0.968], P < .001) | 0.968 ([0.922; 0.987], P < .001) | |
| RUSH‐USC | 0.996 ([0.934; 0.999], P < .001) | 0.904 ([0.703; 0.966], P < .001) | 0.973 ([0.935; 0.989], p < 0.001) | |
| RUSH‐UKY | 0.998 ([0.985; 0.999], P < .001) | 0.908 ([0.744; 0.965], P < .001) | 0.969 ([0.926; 0.988], P < .001) | |
| USC‐UKY | 0.999 ([0.996; 1], P < .001) | 0.988 ([0.97; 0.995], P < .001) | 0.907 ([0.781; 0.962], P < .001) | |
| UCD‐JHU | 1 ([1; 1], P < .001) | 0.999 ([0.998; 1], P < .001) | 0.999 ([0.997; 1], P < .001) | |
| UNM‐JHU | 1 ([1; 1], P < .001) | 0.909 ([0.742; 0.966], P < .001) | 1 ([0.999; 1], P < .001) | |
| UTHSCSA‐JHU | 0.992 ([0.929; 0.998], P < .001) | 0.994 ([0.985; 0.998], P < .001) | 0.966 ([0.917; 0.986], P < .001) | |
| RUSH‐JHU | 0.999 ([0.984; 1], P < .001) | 0.999 ([0.998; 1], P < .001) | 0.999 ([0.999; 1], P < .001) | |
| USC‐JHU | 0.999 ([0.993; 1], P < .001) | 0.911 ([0.72; 0.968], P < .001) | 0.966 ([0.918; 0.986], P < .001) | |
| UKY‐JHU | 1 ([0.999; 1], P < .001) | 0.91 ([0.754; 0.966], P < .001) | 0.967 ([0.919; 0.987], P < .001) | |
| Test–retest | 0.995 ([0.99; 0.997], P < .001) | 0.986 ([0.975; 0.993], P < .001) | 0.985 ([0.972; 0.992], P < .001) | |
| Inter‐scanner | Philips‐Siemens_Prisma | 0.977 ([0.936; 0.992], P < .001) | 0.968 ([0.912; 0.989], P < .001) | 0.966 ([0.914; 0.987], P < .001) |
| Philips‐Siemens_Trio | 0.945 ([0.85; 0.98], P < .001) | 0.956 ([0.878; 0.984], P < .001) | 0.973 ([0.931; 0.989], P < .001) | |
| Siemens_Prisma‐Siemens_Trio | 0.958 ([0.883; 0.985], P < .001) | 0.942 ([0.843; 0.979], P < .001) | 0.981 ([0.952; 0.993], P < .001) | |
| Philips‐GE | 0.966 ([0.905; 0.988], P < .001) | 0.956 ([0.879; 0.984], P < .001) | 0.713 ([0.394; 0.879], P < .001) | |
| Siemens_Prisma‐GE | 0.992 ([0.978; 0.997], P < .001) | 0.956 ([0.879; 0.984], P < .001) | 0.634 ([0.265; 0.841], P = .0013) | |
| Siemens_Trio‐GE | 0.949 ([0.861; 0.982], P < .001) | 0.919 ([0.784; 0.971], P < .001) | 0.716 ([0.4; 0.88], P < .001) | |
Abbreviations: FW, free water; GE, General Electric; JHU, Johns Hopkins University School of Medicine; PMSD, peak width skeletonized mean diffusivity; RUSH, Rush University Medical Center/Illinois Institute of Technology; UCD, University of California Davis; UKY, University of Kentucky; UNM, University of New Mexico Health Sciences Center; USC, University of Southern California; UTHSCSA, University of Texas Health Science Center at San Antonio; WMH, white matter hyperintensity.