Pyruvic Acid Offers High Spatial and Temporal Resolution of MRI

In spite of its wide acceptance in the medical community, magnetic resonance imaging (MRI) suffers from low sensitivity, which can be optimized by injecting patients with potentially toxic contrast agents. However, Swiss scientists have found a way to achieve high spatial and temporal resolution MRI using a safe compound that is naturally generated in the body.

The new study’s findings were published October 2013 in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).


A well-known drawback of MRI is low sensitivity. This problem can be handled with the use of hyperpolarization techniques, which involve injecting patients with substrates that contain a stable carbon isotope that is almost perfectly aligned with the system’s magnetic field. However, the preparation of these contrast agents requires the use of highly reactive compounds called persistent radicals, which can be potentially toxic. Therefore, they have to also be filtered out before injecting the substrates and require additional pharmacologic testing, all of which considerably reduce the MRI contrast, while posing a risk to the patient.

A team of École Polytechnique Fédérale de Lausanne (EPFL; Switzerland) researchers led by Dr. Arnaud Comment developed a cutting-edge solution to this problem. They discovered that high resolution in contrast-enhanced MRI can still be achieved with pyruvic acid, an organic chemical that occurs naturally in the body as a result of glucose breakdown, without the need of persistent radicals.

The scientists exposed frozen, pure pyruvic acid to ultraviolet light for an hour, which resulted in the generation of nonpersistent radicals at a high concentration. The radicals automatically recombine to produce a solution only containing compounds that are naturally present in the body but in much lower concentrations. It was used to perform high-resolution MRI on a mouse brain. The resulting images showed detailed spatial and temporal resolution to the point of tracking the metabolism of pyruvic acid in the animal’s brain.

The new hyperpolarization technology creates a way to perform MRI with compounds that are not toxic, thereby reducing, or altogether eliminating associated health risks. Furthermore, because it does not need additional tests or filtering, the technique will cut down on the time and cost of contrast-enhanced MRI protocols, thus improving the quality of the scans and diagnosis. The authors believe that the technique will be quickly integrated into the clinical setting and call it “a substantial step forward toward clinical radiology free of side effects.”

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École Polytechnique Fédérale de Lausanne