Quantitative transcatheter intraarterial perfusion magnetic resonance imaging monitoring of liver tumor embolization and chemoembolization

Transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization (TACE) are well established palliative therapies for unresectable primary and metastatic liver tumors. However, the optimum embolic endpoints for TAE and TACE remain poorly defined, because the relationship between intra-procedural perfusion changes and tumor responses is unknown. Therefore, there are critical unmet medical needs for intra-procedural monitoring of tumor perfusion alternation in order to optimize patient-specific embolic endpoint selection during TAE and TACE.;TRanscatheter Intraarterial Perfusion (TRIP) MRI techniques using catheter-directed intraarterial contrast injection were developed for intra-procedural monitoring of tumor perfusion changes during liver-directed embolotherapies. Semi-quantitative TRIP-MRI was first developed and evaluated in a rabbit VX2 liver tumor model during serial TAE. A 4D TRIP-MRI technique including radiofrequency (RF) field (B1) calibration and dynamic longitudinal relaxation rate R1 mapping was developed to improve quantification accuracy of perfusion measurement and volumetric spatial coverage using the same animal tumor model during TAE.;Prolonged volumetric B1 mapping provided by existing RF field mapping approaches hinder the clinical application of quantitative TRIP-MRI during interventional procedures. A rapid, accurate and reliable volumetric B1 mapping technique based on the double-angle method (DAM) with innovative catalyzation of longitudinal magnetization was developed. A rapid targeted B1 mapping technique using 3D reduced filed-of-view (inner volume) turbo spin echo (TSE) catalyzed DAM was developed for time-efficient acquisition of local B1 information in targeted treatment regions during interventions.;A fully quantitative TRIP-MRI perfusion analysis approach based on a widely accepted pharmacokinetic model was investigated. Its efficacy was evaluated in a gel perfusion phantom and tested for monitoring intra-procedural tumor perfusion during TAE in a rabbit VX2 liver tumor model. A fully quantitative 4D TRIP-MRI technique was developed specifically for clinical application and was successfully translated to monitor intra-procedural liver tumor perfusion reductions during TACE in patients with Hepatocellular carcinoma (HCC). For the first time, intra-procedural 4D perfusion in HCC during TACE was measured.;At last, the application of quantitative TRIP-MRI to monitor uterine arterial embolization was demonstrated in a rabbit VX2 uterine tumor model. Quantitative TRIP-MRI offers an objective and quantitative method for monitoring intra-procedural perfusion changes during embolotherapies.