Breakthrough MRI Imaging Technique Reveals Cerebral Glucose Metabolism Without Radiation Exposure

Summary: A new MRI imaging technique has been developed by a research team at MedUni Vienna that can map cerebral glucose metabolism without using radioactive substances. The non-invasive procedure uses a harmless glucose solution and can be used with common MRI scanners, providing reliable results for diagnosing metabolic disorders.

Source: Medical University of Vienna

Metabolic disorders play a central role in many common conditions, including Alzheimer’s disease, depression, diabetes, and cancer, which require reliable, non-invasive diagnostic procedures. Until now, radioactive substances were administered as part of the process of mapping glucose metabolism in the brain.

Today, a research team from MedUni Vienna has developed a whole new approach to Magnetic Resonance Imaging (MRI). Using a harmless glucose solution, the procedure generates reliable results and, in principle, can be used with all common MRI scanners.

The results of the study have just been published in the journal Nature Biomedical Engineering.

The study reviewed and significantly improved current diagnostic procedures for mapping glucose metabolism in the brain. Results were generated by measuring blood glucose levels and metabolic products in healthy subjects repeatedly over a period of approximately 90 minutes.

Unlike existing procedures, subjects did not receive radiolabeled glucose but an amount of a harmless glucose solution equivalent to one can of pop. As this substance does not produce a direct signal for the MR imaging method used, glucose concentrations and metabolism were measured indirectly based on the drop in signal intensity for the product of interest.

“The main advantage of this indirect method is that it can be used on other MR devices without any difficulty, since no additional hardware components are required, as is the case with other comparable approaches,” said explained lead researcher Wolfgang Bogner from the Department of Biomedical Imaging and Image-Guided Therapy at MedUni Vienna, emphasizing the clinical significance of the research findings.

Wide range of potential applications

Led by researchers from MedUni Vienna’s Department of Psychiatry and Psychotherapy and Department of Medicine III, the study used the university’s high-performance 7 Tesla MRI scanner. The device was commissioned in 2008 and remains the only ultra-high field MRI scanner available in Austria. Wolfgang Bogner and his team have already demonstrated that the new approach also works on 3-Tesla MR scanners.

“This was an important milestone, as 3T MR systems are extremely prevalent in clinical applications,” said Fabian Niess, lead author of a follow-up study published in Investigative radiology.

Further studies needed to confirm results

Abnormalities in glucose metabolism are a feature of many common diseases. We already know that cancer and tumor cells consume much more glucose than normal cells, an effect that doctors can capitalize on when diagnosing and locating tumors.

Currently, this is done using positron emission tomography in combination with computed tomography (PET-CT), where patients must be injected with a small amount of radioactive glucose. However, the results will need to be verified in further studies before the new, less invasive method developed at MedUni Vienna can be rolled out to benefit patients.

About this neuroimaging research news

Author: Press office
Source: Medical University of Vienna
Contact: Press office – Medical University of Vienna
Picture: Image is credited to Medical University of Vienna

Original research: Access closed.
“1H Magnetic Resonance Spectroscopic Imaging of Deuterated Glucose and 7T Neurotransmitter Metabolism in the Human Brain” by Petr Bednarik et al. Nature Biomedical Engineering

Abstract

1H Magnetic Resonance Spectroscopic Imaging of Deuterated Glucose and 7T Neurotransmitter Metabolism in the Human Brain

Impaired glucose metabolism in the brain has been linked to several neurological disorders. Positron emission tomography and magnetic carbon-13 resonance spectroscopic imaging (MRSI) can be used to quantify glucose metabolism, but these methods involve exposure to radiation, cannot quantify downstream metabolism, or have low spatial resolution.

Deuterium MRI (²H-MRSI) is a non-invasive and safe alternative for the quantification of the metabolism of ²H-labeled substrates such as glucose and their downstream metabolic products, but it can only measure a limited number of deuterated compounds and requires specialized equipment.

Here we show that the proton MRSI (¹H-MRSI) at 7 T has higher sensitivity, chemical specificity and spatio-temporal resolution than ²H-MRSI.

We used ¹H-MRSI in five volunteers to differentiate glutamate, glutamine, vs– deuterated aminobutyric acid and glucose at specific molecular positions, and simultaneously map deuterated and non-deuterated metabolites. ¹H-MRSI, which lends itself to clinically available magnetic resonance equipment, may facilitate the study of glucose metabolism in the brain and its potential roles in neurological disorders.