Summary

Advice

The technology described in this briefing is StoneChecker. It is a medical imaging software tool, based on texture analysis. Its intended use is for evaluating the physical and texture characteristics of kidney stones on non-contrast enhanced CT scan images.
The innovative aspects are an algorithm designed to provide measurements including size and volume of kidney stones, and to identify heterogeneity in the stone structure by enhancing features of the CT image not visible to the naked eye.
The intended place in therapy would be to use it with conventional CT scans in secondary care for people with kidney stones larger than 4 mm.
The main points from the evidence summarised in this briefing are from 3 observational studies in the UK and China. The results of these studies suggest that CT texture analysis using StoneChecker can differentiate uric acid from non-uric stones on unenhanced CT. This may make it possible to predict the number of shocks needed to treat kidney stones.
Key uncertainties around the evidence or technology are that the evidence is limited in quality and quantity. All studies had small sample sizes. One study was experimental, and the analysis was based on passed stones that were provided by patients. A further study was published only as a conference abstract.
The cost of StoneChecker is £5,000 (excluding VAT) as an annual subscription fee. The resource impact is currently unclear because of a lack of evidence in clinical practice.