PhD defence Y. (Yulun) Wu

Brief summary:

In this thesis, I investigated the development and clinical translation of CEST MRI at 3T. We first developed an acquisition pipeline of amide proton transfer (APT) -weighted CEST with clinically acceptable acquisition time at 3T (Chapter 2). This pipeline allows introduction of advanced analysis metrics in terms of the Lorentzian difference (LD), allowing for the semi-quantitative estimation of APT-weighted signal, separated from the nuclear Overhauser effect (NOE) and other effects within the spectrum. The evaluated APT-weighted signal from our pipeline was tested on its within scan session, between scan session and between scanner reproducibility, and was compared with conventional metrics in the reproducibility study of APT-weighted CEST measurements (Chapter 3). High reproducibility of APT-weighted signal in the scans of healthy volunteers and patients can be provided with our developed pipeline. We investigated the origin of this reproducible signal in Chapter 4. We investigated to which extent the APT-weighted CEST signal is reflected by total protein content via proteomics analysis of targeted biopsies in human brain tumors. Our results suggest adaptation of the common assumption that APT-weighted CEST signal is (in part) reflective of total protein content in brain tumors (Chapter 4). In addition, we also developed an optimized pipeline for dynamic glucose enhanced (DGE) CEST imaging including optimized acquisition and advanced post-processing of the human brain imaging data at 3T (Chapter 5).