Which MRI sequences are most sensitive for detecting diffuse axonal injury?

Which MRI sequences are most sensitive for detecting diffuse axonal injury?

• A. T1-weighted and T2-weighted sequences only.
• B. FDG-PET imaging.
• C. Ultrasound.
• D. SWI and DTI.

Answer: (D)

The main idea is that diffuse axonal injury is best revealed by imaging that highlights tiny bleeding in white matter and shows the integrity of white-matter tracts. Susceptibility Weighted Imaging is exceptionally sensitive to microhemorrhages, so it often detects numerous microbleeds along white matter pathways in DAI that standard MRI sequences miss. Diffusion Tensor Imaging evaluates how water diffuses along white matter fibers; when axons are damaged, the diffusion becomes less directionally organized, so measures like fractional anisotropy drop and reveal tract disruption even when routine MRI looks normal. Using these two sequences together gives the most sensitive approach for identifying diffuse axonal injury. Other modalities either don’t pick up microhemorrhages as well (conventional T1/T2), assess metabolism rather than structure (FDG-PET), or aren’t used for intracranial parenchyma evaluation (ultrasound).

The main idea is that diffuse axonal injury is best revealed by imaging that highlights tiny bleeding in white matter and shows the integrity of white-matter tracts. Susceptibility Weighted Imaging is exceptionally sensitive to microhemorrhages, so it often detects numerous microbleeds along white matter pathways in DAI that standard MRI sequences miss. Diffusion Tensor Imaging evaluates how water diffuses along white matter fibers; when axons are damaged, the diffusion becomes less directionally organized, so measures like fractional anisotropy drop and reveal tract disruption even when routine MRI looks normal. Using these two sequences together gives the most sensitive approach for identifying diffuse axonal injury. Other modalities either don’t pick up microhemorrhages as well (conventional T1/T2), assess metabolism rather than structure (FDG-PET), or aren’t used for intracranial parenchyma evaluation (ultrasound).