DCEMRI Modelling in the Presence of Ill-perfused Regions

Motivation: Eliminate physiologically unrealistic results that sometimes arise from extended Tofts (ETM) DCEMRI analyses. Goal(s): Develop and evaluate a model incorporating an avascular acellular compartment. Approach: Synovitis and tenosynovitis DCEMRI from a rheumatoid arthritis (RA) clinical trial, measuring repeatability, and pharmacodynamic response to adalimumab. Results: Despite the additional model parameter in the new model, repeatability, and ability to detect pharmacodynamic responses, were similar to standard ETM. Uptake rate constant repeatability CoV was 35% and pharmacodynamic treatment response ratio was 60% (p=0.027) (cf 39%, 54% and 0.027 for ETM). Extreme unphysiologic extravascular extracellular volumes ve were reported with ETM but not with the new model. Impact: A robust DCEMRI analysis with better face validity increases confidence in the pathophysiologic interpretation of any pharmacodynamic changes.