The study by Cambridge University researchers published in the latest issue of 'Nature' magazine said that cancer tissues, which become more acidic compared to the balanced ones around them, can be identified in the body at early stage by using Magnetic Resonance Imaging (MRI).
By boosting MRI sensitivity over 20,000 times - using a special scanning technique developed - it is now possible to image the molecules used by cancer cells to make energy and growth, the university said.
Traditionally used to detect water and fat in the human body, this level of precision of MRI could be used to spot tumours and to find out if cancer treatments are working effectively at an earlier stage.
Almost all cancers have a lower pH (a measure of acidity) than the surrounding tissue.
Normally, the human body has a system of balancing chemicals with a low pH, acids, and chemicals with a high pH, alkalis, to maintain a constant, healthy pH level, the university said.
In cancer, this balancing system is disturbed, and the tissue becomes more acidic.
Currently, there is no way to safely measure differences in pH in patients, but spotting these areas of acidity could be used to find cancers when they are very small, the study said.
Working with mice, the team found a new way to measure pH levels using this very sensitive MRI technique with a tagged form of bicarbonate.
