Diffusion weighted imaging combining respiratory triggering and navigator echo tracking in the upper abdomen

Area of Science:

• Radiology
• Medical Imaging
• Biomedical Engineering

Background:

• Motion artifacts significantly degrade image quality in upper abdominal Diffusion-Weighted Imaging (DWI).
• Existing motion correction methods, such as respiratory triggering (RT) and navigator echoes (NV), have limitations in addressing these artifacts effectively.

Purpose of the Study:

• To evaluate the efficacy of a novel motion correction technique, RT+NV Track, for upper abdominal DWI.
• To compare the performance of RT+NV Track against conventional RT and NV methods in terms of image quality and efficiency.

Main Methods:

• The RT+NV Track method was developed by integrating RT using a respiration sensor with NV using navigator echoes.
• Image quality was assessed in 10 healthy volunteers and 35 patients using DWI and apparent diffusion coefficient (ADC) maps.
• Quantitative metrics included signal-to-noise efficiency (SNR_efficiency) and coefficient of variation (CV) of ADC values, alongside qualitative assessments by five radiologists.

Main Results:

• RT+NV Track demonstrated significantly higher SNR_efficiency compared to both RT and NV methods (p < 0.001).
• The new method showed superior performance in CV and visual evaluation of ADC values compared to RT (p < 0.001) and was equal or better than NV.
• RT+NV Track effectively acquires expiratory data and corrects for respiratory depth variations, minimizing image degradation even in patients with rapid breathing.

Conclusions:

• The RT+NV Track method represents an efficient approach for upper abdominal DWI.
• It successfully combines the advantages of RT and NV techniques, leading to consistently good image quality.
• This method enables stable and high-quality imaging within a reduced scan time.