New York, May 15 (IANS): US researchers have developed a new imaging method that can detect liver cancer and other liver diseases at an earlier stage than what current leading methods can, reports a new study.

"Liver cancers associated with high mortality rates and poor treatment responses are often diagnosed in the late stages because there is not a reliable way to detect primary liver cancer and metastasis at a size smaller than one centimetre," said lead study author Jenny Yang, professor at Georgia State University, in the US.

The new method can scan liver tumours that measure less than 0.25 millimetres, the study reported.

Magnetic resonance imaging (MRI) is the leading imaging technique to detect disease without using radiation. MRI contrast or imaging agents aid MRI techniques to obtain tissue-specific images.

However, according to the researchers the applications of MRI contrast agents are not effective for early detection of cancerous tumours because they are hampered by uncontrolled blood circulation time, low relaxation rate or sensitivity, and low specificity.

Most contrast agents, Yang said, are rapidly excreted from the liver, not allowing sufficient time to obtain quality imaging.

To more effectively detect cancerous tumors at an early stage, the researchers developed a new class of protein-based contrast agents (PRCAs) and an imaging methodology that provides robust results for the early detection of liver cancer and other liver diseases.

"Our new agents can obtain both positive and negative contrast images within one application, providing double the accuracy and confidence of locating cancerous tumors," Yang said.

The researchers have shown proof-of-concept that the new method can be used to detect cancerous liver tumours at an early stage with high sensitivity.

They have also demonstrated that these new agents better aid the imaging of multiple organs, including the kidney and blood vessels, in addition to the liver and tumours.

The findings were published in the journal Proceedings of the National Academy of Sciences.