Deformation-based morphometry: a sensitive imaging approach to detect radiation-induced brain injury?

Area of Science:

• Neuroimaging
• Radiotherapy Research
• Medical Physics

Background:

• Radiotherapy for brain tumors can cause cognitive impairments.
• Deformation-based morphometry (DBM) shows promise for managing radiation-induced brain sequelae.
• DBM analysis using Jacobian determinants (JD) can detect local vulnerability in healthy brain tissue post-irradiation.

Purpose of the Study:

• To analyze the significance of DBM using JD to detect local vulnerability of healthy cerebral tissue in an animal model of brain irradiation.
• To investigate macrostructural and microstructural changes in the brain following irradiation.

Main Methods:

• Rats underwent fractionated whole-brain irradiation (WBI, 30 Gy).
• Multiparametric MRI (anatomical, diffusion, vascular) was performed longitudinally.
• DBM analyzed macroscopic changes; diffusion metrics (MD) and cerebral blood volume (CBV) quantified microstructural changes.

Main Results:

• DBM revealed time-course macrostructural changes, some transient, some long-lasting.
• The corpus callosum and cortex were identified as vulnerable brain areas.
• DBM changes correlated with microstructural alterations (diffusion, CBV) and immunohistology findings.

Conclusions:

• DBM detects local macrostructural changes post-brain irradiation, identifying susceptible brain structures.
• These findings may enhance imaging studies on brain radiotoxicity in patients.