Deimel, JudithJudithDeimel2025-10-212025-10-212025-09-12Technische Universität Hamburg (2025)https://hdl.handle.net/11420/58080Perfusion imaging is becoming increasingly important for monitoring how tumors respond to therapy. It provides information about the tumor’s blood flow and vascular state. Small changes in the blood vessels happen before any anatomical changes, e.g. changes in tumor size. One approach to perfusion imaging is three-dimensional dynamic-contrast-enhanced (DCE) ultrasound. Ultrasound is widely available, low-cost and safe to use at the bedside. In 3D DCE ultrasound, a contrast agent is injected and its flow through the tumor is recorded over time. This results in 4D data consisting of the three spatial dimensions and the time evolution. This thesis investigates Fourier Neural Operators as surrogate models for partial differential equation models to solve the inverse problem of estimating tissue-specific parameters, such as blood flow, from these measurements.enhttps://creativecommons.org/licenses/by/4.0/Inverse Problems3D dynamic contrast enhanced ultrasoundneural operatorsperfusion imagingTechnology::610: Medicine, HealthComputer Science, Information and General Works::006: Special computer methods::006.3: Artificial IntelligenceMaster Thesishttps://doi.org/10.15480/882.1602110.15480/882.16021Ruprecht, DanielDanielRuprechtGötschel, SebastianSebastianGötschel10.15480/882.476510.1109/TMI.2022.3197363Other