Restricted diffusion in benign intracranial neoplasms: a narrative review

Area of Science:

• Neuroradiology
• Oncology
• Medical Imaging

Background:

• Diffusion-weighted imaging (DWI) is crucial for assessing brain tumor cellularity and grade.
• Restricted diffusion on MRI typically indicates high-grade malignancy due to increased cellularity.

Purpose of the Study:

• To review the diagnostic challenges posed by benign central nervous system (CNS) neoplasms that exhibit restricted diffusion on MRI.
• To highlight exceptions to the general rule that restricted diffusion signifies malignancy.

Main Methods:

• Integrated review of clinical data.
• Radiological-pathological correlation.
• Analysis of MRI findings in CNS tumors.

Main Results:

• High-grade tumors commonly show restricted diffusion.
• Benign CNS tumors rarely exhibit restricted diffusion, but exceptions exist.
• Restricted diffusion in benign neoplasms can mimic malignant features.

Conclusions:

• Awareness of benign CNS tumor exceptions presenting with restricted diffusion is vital for accurate diagnosis.
• DWI findings must be interpreted in clinical and pathological context to avoid misdiagnosis.
• Knowledge of these imaging nuances aids in preventing diagnostic errors.