Magnetic Resonance Guided High-Intensity Focused Ultrasound (MRgHIFU) is an interventional ablative modality, used to treat conditions such as tumors and essential tremor. In recent years, the modality has received regulatory approval for the treatment of many types of cancer, but has yet to begin early-phase clinical trials for liver cancer. Primary liver cancers such as hepatocellular carcinoma (HCC), in the absence of transplantation, have low survival rates. Secondary liver tumors have even lower survivability and are compounded by high surgical ineligibility and poorer prognosis.

MRgHIFU has been proven feasible for liver tumor ablation, and the technology is CE-marked under ultrasound guidance. The translation of MRgHIFU encountered complications, due to the scattering from the rib cage and the respiratory motion of the patient. However, MRgHIFU systems offer many advantages to the procedure, including real-time temperature mapping and the ability to be integrated with in-place MRI scanners.

Many technologies are in development to treat complications with MRgHIFU for hepatobiliary tumor sites. The main subject of this thesis was to develop, test, and characterize a sonosensitive perfluorocarbon emulsion formula for droplet-enhanced heating during MRgHIFU. This has the potential benefit of increasing temperature gain during ablative HIFU procedures to reduce time, power, and risk. This formula can be used both under ultrasound guidance and under MRI guidance. Additionally, the emulsion formula has also shown theragnostic capabilities, providing imaging with ¹⁹F-MRI, in addition to localized delivery of chemotherapy. The formula is comprised of a high boiling point perfluorocarbon emulsified with a synthetic fluorinated surfactant. The oil-like droplets were designed to be 1-2 µm in diameter for prolonged systemic endovascular circulation and delivered to perfused tissues. Studies have shown significant thermal enhancement in ex vivo pig livers and kidneys and tissue-mimicking flow phantoms. As thermal ablation in perfused tissues is complicated by the heat sink effect, the application of this formula could potentially render the perfusion effects advantageous.