AI measures kidney size six times faster than humans
A 2-dimensional MRI image of the abdomen, with the outline of the two kidneys traced in red and yellow. This is an example of a single ‘slice’ of the MRI scan. Image Courtesy of Sheffield Teaching Hospitals NHS Foundation Trust.
Artificial intelligence once felt like it had a home only in science fiction stories, but there’s no doubt it’s now becoming an integral part of our world.
The potential threats and opportunities of AI to our future made multiple headlines in 2023.
Yet this powerful technology can provide us with many benefits, from improved healthcare, to safer cars and workplaces, to better products and services.
The PKD Charity recently interviewed two researchers from Sheffield Teaching Hospitals NHS Foundation Trust: Dr Jonathan Taylor, Senior Medical Physicist, and Professor Albert Ong, Consultant Nephrologist and Clinical Lead for Genetics. Albert is also Professor of Renal Medicine at the University of Sheffield.
They worked with others across Europe to develop an AI program to accurately measure kidney size.
These measurements are important in PKD because they help to predict when a person’s kidneys might fail.
Professor Ong said: “Our AI tool performed as well as the human expert analysts and did the job approximately six to seven times faster.”
Dr Taylor, who was involved in designing and testing the AI tool, explained why the ‘old’ process for measuring kidneys was so Labour intensive: “MRI scans give a 3-dimensional view of the kidney. Scans are made up of lots of 2-dimensional ‘slices’ stacked on top of each other, about 50 to 60 in total.
“To measure total kidney volume an operator would previously have to go through, slice-by-slice, and carefully trace round the edge of each kidney on a computer screen.”
Dr Taylor said AI tools are very good at recognising objects in images and he was fairly confident that they could train a tool to recognise and trace round kidneys in abdominal images.
To design the AI system they used a large collection of kidney MRI images from a previous European PKD clinical study called CYSTic. Their radiographer colleague Richard Thomas manually traced round the kidneys in all images. They then fed this collection of images and kidney tracings to an AI algorithm until it had learned to do the tracing process itself to a high standard.
The AI software is embedded within their standard hospital computer systems and makes predictions about where the kidney is located in MRI images.
Dr Taylor said: “The AI tool is very good at identifying the boundaries of kidneys in MRI images and therefore measuring total kidney volume. It has a high degree of accuracy and is comparable to decision-making performed by trained workers. In the vast majority of cases, the AI tool results need either no corrections or very minor corrections by a human operator.
“The AI result is typically available in less than one minute. It happens automatically as soon as the MRI scan is sent from the scanner. A human operator will then check the results. The total time is now less than 10 minutes on average. Each case would previously take about one hour to process manually.
Professor Ong explained how the AI tool is being used in kidney care. He said: “The tool has been used since 2022 in the 3D lab at Sheffield Teaching Hospitals which performs all the clinical kidney volume measurements. It has already resulted in significant time savings and the analysts like using it!
“This tool – and others like it – will enable kidney clinics worldwide to measure kidney volume quickly and accurately. It will make the measurement of kidney volume possible at clinics where there is a lack of specialist expertise. We plan to share our tool openly to allow it to be used around the world.
“The time savings made by the laboratory allow them to do more measurements and also reduce the cost of analysis.”