Registration Strategies for Whole-Body Diffusion-Weighted MRI Stitching

With the development of ultra-fast magnetic resonance imaging sequences, whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) becomes a popular diagnostic tool in patient cancer screening. Modality can improve plenty of clinical investigations such as lymphoma, multiple melanoma or metastatic bone cancer diagnosis. Because of vast body coverage and MR scanner limitations, whole-body image is acquired in blocks, called stations. Precise ‘stitching’ of whole-body stations is essential to ensure correct image formation, yet there are not many commercially available registration algorithms. We developed and investigated several registration methods based on apparent diffusion coefficient (ADC) and diffusion-weighted images (DWI) to improve station-to-station registration and WB-DWI image quality. This paper reports on registration results of 52 whole-body DWI images and compares them with other already existing methods. Proposed registration techniques based on ADC images demonstrated superior performance over other registration methods.