Diffusion tensor magnetic resonance imaging of the pancreas

Area of Science:

• Radiology
• Biomedical Imaging
• Oncology

Background:

• Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), is a leading cause of cancer-related mortality.
• Accurate and early detection of PDAC is crucial for improving patient outcomes.
• Diffusion tensor imaging (DTI) offers insights into tissue microstructure by measuring water diffusion properties.

Purpose of the Study:

• To develop and validate a DTI protocol sensitive to the diffusion and perfusion characteristics of healthy and malignant pancreatic tissues.
• To assess the ability of DTI parameters to distinguish between normal pancreatic tissue and PDAC.
• To investigate the influence of intra-voxel incoherent motion (IVIM) on DTI measurements in the pancreas.

Main Methods:

• A 3T DTI protocol was applied to 28 healthy volunteers and 9 patients with PDAC.
• Multi-b diffusion-weighted imaging (DWI) was used in healthy volunteers to assess IVIM.
• Parametric maps of diffusion coefficients (λ1, λ2, λ3, ADC) and fractional anisotropy (FA) were generated and analyzed.

Main Results:

• Healthy pancreatic tissue exhibited specific DTI values at b-values of 0 and 500 s/mm², with significant changes observed when using b-values of 100 s/mm².
• A fast IVIM component was identified in healthy pancreas tissue at lower b-values.
• PDAC tissues showed significantly lower diffusion coefficients and reduced changes between b-value sets compared to normal pancreas, indicating higher cellularity and diminished IVIM.

Conclusions:

• DTI with optimized b-values (0 and 100 s/mm²) can characterize pancreatic water diffusion and anisotropy, accounting for IVIM.
• The observed differences in diffusion coefficients and their changes in PDAC compared to normal tissue aid in malignancy detection.
• This DTI protocol shows promise for non-invasively identifying pancreatic cancer.