Diffusion-weighted imaging in pediatric body MR imaging: principles, technique, and emerging applications

Area of Science:

• Medical Imaging
• Radiology
• Biophysics

Background:

• Diffusion-weighted (DW) imaging is an advanced technique providing indirect information on tissue microenvironments and lesions.
• Challenges in body imaging include reduced signal-to-noise ratio and motion-related degradation, particularly from respiration.

Purpose of the Study:

• To review the principles, challenges, and applications of DW imaging in pediatric body imaging.
• To highlight how technical advancements address limitations in DW imaging for body applications.

Main Methods:

• Utilizing smaller b values and motion compensation techniques to improve image quality.
• Performing DW imaging with breath-hold or free-breathing sequences, with or without respiratory triggering.

Main Results:

• Different normal tissues exhibit distinct signals on DW imaging based on water molecule mobility.
• Specific tissues like lymph nodes and spleen show restricted diffusion, while others exhibit T2 shine-through.
• Fatty marrow and bone cortex appear dark on DW images and apparent diffusion coefficient maps.

Conclusions:

• DW imaging is increasingly valuable for detecting, characterizing, and monitoring abnormalities in pediatric body imaging.
• Emerging applications include tumor assessment, liver fibrosis grading, abscess detection, and inflammatory bowel disease evaluation.