A new analysis of 10 studies suggests that a specialized MRI technique called neurite orientation dispersion and density imaging (NODDI) may help doctors tell the difference between gliomas and brain metastases. These two types of brain tumors can look similar on standard scans but require different treatments.
The analysis looked at three NODDI measurements: orientation dispersion index (ODI), intracellular volume fraction (V-IC), and isotropic volume fraction (V-ISO). The results showed that ODI and V-ISO were significantly lower in gliomas compared to brain metastases, especially in the contrast-enhancing region of the tumor. For glioblastomas, V-ISO in the surrounding edema area was also lower.
However, the study has important limitations. Only a small number of studies were included, and the analysis did not report on patient outcomes or safety. The findings suggest NODDI could be a useful tool, but more research is needed before it becomes standard practice.
For now, this imaging technique offers a promising way to non-invasively differentiate brain tumors, potentially reducing the need for biopsies. But patients should discuss all diagnostic options with their doctor.