The technology

StoneChecker is medical imaging software used to measure key kidney stone parameters to generate a set of textual metrics. It uses an application (TexRAD, licensed by Feedback Medical Ltd) that analyses the texture in an existing radiological scan. The aim is to help clinicians assess a stone's heterogeneity and any characteristics not visible to the naked eye. It creates a visual 'map' of a kidney stone.

The technology is designed to be used with conventional CT scans to help clinical decision making about diagnosing and treating people with kidney stones. It imports imaging data and calculates metrics based on individual pixel data points within a given region of interest. These metrics assess stone heterogeneity, including texture irregularity, not provided by conventional CT scans. The technology can also use filters to extract and enhance existing CT images to help assess stone composition. This can potentially be used to predict treatment failure on pre-treatment CT, and to identify and select patients who are most likely to benefit from the treatment.

StoneChecker software runs on existing Windows-based machines or workstations, and can be integrated with a hospital picture archiving and communication system to import files containing CT images.


StoneChecker uses an algorithm aimed at measuring the size and volume of kidney stones. It can also assess stone heterogeneity using filtration-histogram-based texture analysis, which enhances the details seen with conventional CT. Currently, there is no standardised method of measuring the physical and texture parameters that enable clinicians to predict treatment outcomes.

Current care pathway

The NICE guideline on renal and ureteric stones: assessment and management recommends that low-dose non-contrast CT should be offered to adults (except if pregnant) with suspected renal colic within 24 hours of symptoms presenting.

StoneChecker would be used with standard CT scans in people with kidney stones to measure stone parameters and to inform clinical decision making about treatment choice.

Population, setting and intended user

StoneChecker is intended to be used with non-contrast CT scans in a secondary care setting in people with kidney stones to measure and evaluate the stones. The device would most likely be used by urological surgeons or radiologists. The company estimates the technology could be used to evaluate at least 100,000 cases of kidney stones each year in the UK.


Technology costs

StoneChecker costs at £5,000 (excluding VAT) as an annual subscription fee. The company stated that this is potentially only an early-adopter price. It explained that a future subscription model may take into consideration such factors as the volume of cases analysed per site or per workstation, or the number of users.

Costs of standard care

No estimate for the complete cost of existing care for CT in people with kidney stones could be identified. In the NHS, the cost of non-contrast CT of 1 area of the body ranges from £71 to £81, depending on the person's age.

Resource consequences

There is no evidence on the resource and cost consequences of StoneChecker. It is imaging software and is intended to be used with conventional CT scans. Use of the technology is not expected to have any significant impact on resource use. However, extra staff time may be needed for training on how to use the technology and for interpreting the metrics. This might be offset by improving workflow for urologists and radiologists.