Diffusion tensor MRI of the human kidney.

Area of Science:

• Medical Imaging
• Diffusion MRI
• Renal Physiology

Background:

• Kidney diffusion imaging is crucial for clinical diagnosis.
• Existing methods face challenges like abdominal susceptibility variations and motion sensitivity.
• Acquisition time is limited to a single breath-hold.

Purpose of the Study:

• To characterize human kidney diffusion anisotropy using diffusion-weighted imaging.
• To implement a novel segmented EPI protocol for high-resolution diffusion imaging within one breath-hold.
• To overcome limitations of conventional diffusion imaging in the abdomen.

Main Methods:

• Utilized a diffusion-weighted, single-shot echo planar imaging (EPI) sequence.
• Implemented an isotropic, diffusion-weighted, segmented EPI protocol.
• Acquired apparent diffusion tensor (ADT) data within a single breath-hold.

Main Results:

• Fractional anisotropy (FA) values were 0.22 ± 0.12 (cortex) and 0.39 ± 0.11 (medulla).
• Apparent diffusion coefficient (ADC) values were 2.89 ± 0.28 x 10⁻⁹ m²/s (cortex) and 2.18 ± 0.36 x 10⁻⁹ m²/s (medulla).
• The novel protocol enabled high-resolution diffusion-weighted images within one breath-hold.

Conclusions:

• Diffusion anisotropy varies between human kidney cortex and medulla.
• Rotationally invariant diffusion measurements are essential for clinical kidney applications.
• The developed segmented EPI protocol shows promise for overcoming current diffusion imaging limitations in the abdomen.