An enhanced type of MRI can detect much smaller tumors than ever before — some tinier than a pea —in an advance that could open a new age in diagnosing cancer without surgery researchers say. The experimental technique examines the lymph nodes for signs of spreading cancer. The finding will be published by New England Journal of Medicine on June 19 2003.

Doctors already routinely use magnetic resonance imaging or MRI to check the lymph nodes to see whether cancer that originated somewhere else in the body — say in the breast or the prostate gland — is spreading. But the enhanced technique proved superior to conventional MRIs when tested with cancer that had spread from the prostate.

The leader of the research Dr. Mukesh Harisinghani (Mass. General Hospital) said his team has also had preliminary success using the approach to detect the spread of breast testicular bladder and kidney cancer.