Reverse Encoding Distortion Correction for Clinical Head Echo-Planar Diffusion-Weighted MRI: Initial Experience

Area of Science:

• Radiology
• Medical Imaging
• Neuroimaging

Background:

• Echo-planar imaging (EPI) diffusion-weighted imaging (DWI) is crucial for brain imaging.
• Image distortion in EPI-DWI can affect diagnostic accuracy, particularly in specific brain regions and for certain pathologies.
• Reverse encoding distortion correction (RDC) is a recently commercialized technique to address EPI-DWI distortions.

Purpose of the Study:

• To evaluate the feasibility and effectiveness of RDC for EPI-DWI in clinical head MRI.
• To assess the impact of RDC on image distortion and quantitative metrics in normal brain structures and pathologies.

Main Methods:

• Fifty patients underwent head MRI with both single-shot (SS) EPI-DWI and RDC-EPI-DWI.
• Image distortion, Dice similarity coefficient (DSC), distortion ratios, and mean apparent diffusion coefficient (ADC) values were assessed in the pons, temporal lobe, and frontal lobe.
• Image distortion and mean ADC values were also evaluated for intracranial and extracranial pathologies.

Main Results:

• RDC-EPI-DWI significantly reduced image distortion and improved mean ADC values in the pons and temporal lobe compared to SS-EPI-DWI.
• No significant differences in distortion or ADC values were observed in the frontal lobe between the two methods.
• Significant reductions in distortion and increased mean ADC values were noted for extracranial pathologies with RDC-EPI-DWI, but not for intracranial pathologies.

Conclusions:

• RDC-EPI-DWI is a feasible and effective method for reducing image distortion in head MRI.
• The technique demonstrates particular benefit for brain parenchyma in the skull base and for extracranial pathologies.
• RDC-EPI-DWI enhances diagnostic confidence by improving image quality and quantitative accuracy in specific clinical scenarios.