The Quantitative Imaging Biomarkers Alliance, now continued under the Quantitative Medical Imaging Coalition, has set out technical standards for liver MR elastography covering acquisition, reconstruction, quality assurance and analysis across vendors.

Its central quantitative claim is that, when the standard is followed, a change in liver stiffness of at least 19% between two scans represents a true biological change with 95% confidence. This rests on a within-subject coefficient of variation of about 7%.

This matters for follow-up. Clinicians increasingly use stiffness to track fibrosis in MASLD and viral hepatitis, and a small rise or fall between scans is easily over-interpreted.

For departments, adopting the standard protocol makes serial results comparable. For referrers, a change smaller than about a fifth should be read as within measurement noise unless other evidence supports it.

Treat a liver stiffness change under about 19% between MR elastography scans as possibly measurement noise
Use the same scanner and protocol for serial elastography where possible
Report image quality and region-of-interest size with each stiffness value
Align local protocols with the published technical standard before using stiffness to track treatment response

Why it matters

It gives clinicians a concrete threshold for deciding whether fibrosis has really changed.

The statistics, in plain English

A within-subject coefficient of variation of 7% means repeated scans of the same unchanged liver typically differ by about that much; to be 95% sure a change is real, it needs to be close to three times larger, about 19%.