Pigeons can diagnose malignant breast cancerous tissue

Visual abilities of pigeons usable for medicine?
Pigeons can distinguish benign and malignant breast tissue on images and correctly identify cancer-related microcalcifications on mammograms, according to researchers from the University of California (UC). The latter is "a task that is extremely difficult even for qualified human observers," said the UC.

According to the US researchers, pigeons have special visual abilities that could possibly be used for medical purposes. "With some training and targeted food fortification, pigeons were as good as humans categorizing digitized slides and mammograms of benign and malignant human breast tissue," says study author Professor Richard Levenson of UC. The scientists have published their findings in the journal "PLoS One".

The visual abilities of pigeons could also be helpful in medicine. (Image: missisya / fotolia.com)

Training on the monitor
Based on earlier studies on the special visual abilities of pigeons, scientists at the University of California have investigated whether the birds may also be able to contribute to the evaluation of images for cancer diagnosis. For the study, 16 pigeons on a monitor learned to distinguish images of benign breast tissue from images of malignant breast tissue. They had to pick the right answer on the monitor and then received a reward. If the decision was wrong, there was no reward and the birds got to see the picture again to correct their mistake. In a first series of experiments, the pigeons worked through numerous pictures with different magnifications, colors and contrast levels, before they were to apply the acquired knowledge in a second attempt.

Combined results with 99 percent accuracy
In the second experiment, the pigeons once again got pictures of benign and malign breast tissue, but these were completely new pictures. Also, they received a reward in this attempt, regardless of whether their decision was right or wrong. The test showed that "the pigeons were able to generalize what they had learned and largely correctly identify the digitized slides," said Prof. Levenson. The birds are remarkably adept at differentiating between benign and malignant breast cancer, the physician reports. This ability usually requires a long training period in humans. The diagnostic accuracy of the pigeons has increased from initially 50 percent to almost 85 percent after about two weeks of training. When combining the results of four birds, the accuracy even increased to 99 percent.

Doves in medicine?
In another experiment, the scientists trained the pigeons to differentiate mammography images with and without microcalcifications, achieving an average accuracy of 84 percent. An achievement that, according to the researchers, is also on par with human radiologists. However, the pigeons had difficulties in distinguishing the density of the breast tissue, which is also crucial in the determination of breast cancer. Overall, however, according to the researchers, the pigeons showed a promising potential that could also be used for medical purposes. For example, the birds could be used to validate newly developed imaging technologies, which is a "difficult, time-consuming and costly activity" that would normally require medical professionals to be recruited for this "comparatively profane task," Levenson and colleagues write. (Fp)