Repeatability of Apparent Diffusion Coefficient at 3.0 Tesla in Normal Pancreas.

Area of Science:

• Radiology
• Medical Imaging
• Diffusion-Weighted Imaging

Background:

• Diffusion-weighted imaging (DWI) is a valuable MRI technique.
• Apparent diffusion coefficient (ADC) quantification provides insights into tissue microstructure.
• Understanding the repeatability of ADC measurements in normal organs is crucial for clinical applications.

Purpose of the Study:

• To assess the test-retest repeatability of apparent diffusion coefficient (ADC) measurements in the normal pancreas using diffusion-weighted imaging (DWI).

Main Methods:

• Twenty-six healthy volunteers underwent two DWI scans at 3.0-T with repositioning.
• Two independent readers measured ADC values in the pancreatic head, body, and tail.
• Global pancreatic ADC was calculated, and repeatability was analyzed using Bland-Altman analysis, ICC, and CV.

Main Results:

• The global pancreatic ADC demonstrated the best test-retest repeatability (CV, 6%; ICC, 0.79).
• Regional ADC measurements (head, body, tail) showed lower repeatability (CVs, 9%, 8%, 8%; ICCs, 0.81, 0.52, 0.68).
• Intra-observer and inter-observer reproducibility for global pancreatic ADC were acceptable.

Conclusions:

• The whole pancreas exhibits the best test-retest repeatability for ADC measurements (CV 6%).
• Interpreting longitudinal changes in regional pancreatic ADC values requires caution due to inherent location-based variability.
• These findings are important for the clinical application of DWI in pancreatic imaging.