Investigation of a pulsation artefact reduction technique in diffusion-weighted magnetic resonance imaging of the liver

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One problem in magnetic resonance diffusion-weighted imaging (DWI) of the liver is the signal loss in the left liver lobe, which is caused by cardiac pulsation. The aim of this proposal is to improve the image quality of liver DWI by reducing this artefact and achieving black-blood images at the same time. For this purpose, a mixed protocol shall be used, whose feasibility for this task was proven in a recent own volunteer study. It contains a conventional bipolar diffusion encoding at a small b-value (50 s/mm²), and a flow-compensated diffusion encoding at a high b-value (800 s/mm²). This protocol shall be used in a prospective patient study including patients with known or suspected liver lesions. The visibility of the lesions in the left liver lobe is one of the key parameters that shall be evaluated. To achieve a further improvement of the image quality, advanced postprocessing schemes shall be developed and evaluated. They comprise conventional approaches featuring e.g. outlier detection. Moreover, convolutional neural networks shall be trained to generate high quality images from the set of the acquired diffusion-weighted images.