Performance of Single-Shot Echo-Planar Imaging in Diffusion Tensor Imaging in Rat Sciatic Nerve Compared With...

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Radiology

Background:

• Diffusion Tensor Imaging (DTI) is crucial for assessing nerve integrity.
• Single-shot echo-planar imaging (SS-EPI) and readout-segmented EPI (RS-EPI) are common DTI sequences.
• Comparing SS-EPI and RS-EPI performance in peripheral nerve DTI is essential for optimizing imaging protocols.

Purpose of the Study:

• To compare the diagnostic performance of SS-EPI and RS-EPI for DTI of the rat sciatic nerve.
• To evaluate image quality metrics including nerve morphology, distortions, and homogeneity.
• To correlate DTI parameters with histopathological findings.

Main Methods:

• Eight Sprague-Dawley rats underwent 3T MRI using both SS-EPI and RS-EPI DTI sequences.
• Image quality was scored for nerve sharpness, artifacts, homogeneity, and contrast-to-noise ratio (CNR).
• Pearson correlation coefficients were calculated between DTI parameters (FA, AD, RD, ADC) and histopathology.

Main Results:

• SS-EPI demonstrated significantly higher image quality scores than RS-EPI for nerve margin sharpness, artifacts, and homogeneity (P < 0.008).
• Contrast-to-noise ratio (CNR) was significantly higher for SS-EPI DW images (P < 0.001).
• Higher correlation coefficients were observed for FA and RD from SS-EPI compared to RS-EPI, with significant correlations between FA/RD and myelin thickness/fiber diameter.

Conclusions:

• SS-EPI provides significantly better image quality for rat sciatic nerve DTI than RS-EPI.
• FA and RD derived from SS-EPI DTI are sensitive biomarkers for detecting sciatic nerve histopathological changes.
• SS-EPI is a promising sequence for DTI of the peripheral nervous system.