Application of diffusion tensor imaging in distinguishing high-grade gliomas from brain metastases

High-grade gliomas and brain metastases are denoted as the most common brain tumors [۱]. High-grade gliomas have an infiltrative growth pattern, whereas brain metastases grow in an expansive pattern with displacement of surrounding brain tissues. The accurate distinguishing between these two types of brain tumors is necessary because alters patient management and affects outcome [۲]. Conventional MRI has limitations in the detection of high-grade gliomas from metastases due to similar enhancement patterns [۳]. The use of advanced MRI techniques, such as diffusion tensor imaging (DTI), is widespread in intracranial neoplasms. Mean diffusivity (MD) and fractional anisotropy (FA) are the two commonly used DTI metrics that describe the magnitude and directionality of water diffusion and can provide valuable information about orientation and tissue structure [۴]. This study aims to review the application of diffusion tensor imaging in distinguishing high-grade gliomas from brain metastasis.Literature searches of Google Scholar, PubMed, and AltaVista search engines were conducted with the keywords “diffusion tensor imaging”, “high-grade gliomas”, “brain metastasis”. Then, different articles related to the topic extracted and reviewed.Based on the results, it was determined that DTI metrics are different in high-grade gliomas and brain metastases [۵]. Peritumoral MD is mainly higher in brain metastases than high-grade gliomas because of more vasogenic edema with excessive extracellular fluid surrounding brain metastases. On the other hand, this excessive extracellular fluid around metastases leads to less specific diffusion directionality and reduce FA. Combining these metrics provides useful information for the differentiation of high-grade gliomas from brain metastases.In conclusion, DTI can be a promising technique for distinguishing high-grade gliomas from brain metastases.

Keywords:

Diffusion tensor imaging” , “High-grade gliomas” , “Brain metastases