Having defeated humans at chess and Go!, computers also outperformed us on another sophisticated task: brain cancer diagnosis. This computer program, which was recently developed at Case Western Reserve University, could diagnose 12 out of 15 brain cancer patients correctly through analyzing their MRI scans. Meanwhile, for two other physicians that studied the same MRI scans, one got 8 and the other one got 7 right. Utilizing radiomic features, this program was nearly twice as accurate as two neuron-radiologists combined!
This progress is really important. Because MRI scans for radiation necrosis and recurrent brain cancer have almost indistinguishable patterns, physicians often have difficulty in differentiating them just by eyeballing the images. Treatments for these two ailments are also vastly different, so the quicker and more accurately we can identify the disease, the better the patients would be.
So how does this program work? Researchers combined machine learning algorithms with
radiomics, an emerging field that “aims to extract large amount of quantitative features from medical images sing data-characterization algorithms” (Wikipedia). Using sample MRI scans from numerous patients, scientists trained computers to recognize radiomic features that differentiate brain cancer from radiation necrosis. Then computer algorithms would help sort out the most discriminating radiomic features, or the subtle details that physicians often missed.
For example, let's look at the two different MRI scans for tumor recurrence and radiation necrosis below. It’s quite difficult to notice the disparity between two scans and decide which one is which. The program’s images output, however, clearly display which one has less heterogeneity (shown in blue) which would indicate radiation necrosis; and which one has more heterogeneity (shown in red), which is representative of tumor recurrence.
Currently, the researchers are still trying to improve the program’s accuracy by using a much larger collection of images for the machine learning algorithms. In the future, this program would be a great tool for neuro-radiologists in inspecting suspicious lesions and diagnosing their patients.
Sources:
https://www.sciencedaily.com/releases/2016/09/160915132448.htm
https://en.wikipedia.org/wiki/Radiomics







