Apparent diffusion coefficient of normal adrenal glands

Area of Science:

• Radiology
• Medical Imaging
• Diffusion-Weighted MRI

Background:

• Normal adrenal gland assessment is crucial for diagnosing various conditions.
• Diffusion-weighted magnetic resonance imaging (DW-MRI) offers a non-invasive method to evaluate tissue microstructure.
• Apparent diffusion coefficient (ADC) measurements provide quantitative insights into tissue water diffusion.

Purpose of the Study:

• To determine the feasibility and reliability of apparent diffusion coefficient (ADC) measurements in healthy adrenal glands.
• To compare ADC values between prepubertal and postpubertal individuals.
• To establish the reproducibility of ADC measurements by multiple radiologists.

Main Methods:

• Retrospective analysis of DW-MRI scans from 32 healthy subjects (12 prepubertal, 20 postpubertal).
• Acquisition of images using a 1.5 T scanner with b-values of 0, 20, 500, and 1000 s/mm².
• Pixel-by-pixel ADC value measurement with automatic co-registration to ADC maps.

Main Results:

• Mean ADC values for right adrenal glands were 1.44 × 10⁻³ mm²/s (prepubertal) and 1.23 × 10⁻³ mm²/s (postpubertal).
• Mean ADC values for left adrenal glands were 1.58 × 10⁻³ mm²/s (prepubertal) and 1.32 × 10⁻³ mm²/s (postpubertal).
• ADC values were significantly higher in the prepubertal group (p < 0.05), with excellent inter-reader agreement (ICC 0.84-0.94).

Conclusions:

• DW-MRI measurements of normal adrenal glands are feasible and reliable.
• The study supports the utility of ADC measurements for evaluating small anatomical structures.
• These findings provide a baseline for future research on adrenal gland pathologies using DW-MRI.