Kelly Catherine McPhee1, Jennifer E. H. Baker1,2, Katayoun Saatchi3, Urs O. Hfeli3, Stefan a Reinsberg1
1Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada; 2Radiation Biology Unit, BC Cancer Research Centre, Vancouver, British Columbia, Canada; 3Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
In this pilot study, we investigate a novel, high-molecular weight (HMW) contrast agent, hyperbranched polyglycerol (HPG), doubly labeled with Gd and a fluorescent marker. Longitudinal measures of T1 were made in vivo. We observed accumulation of HPG over several days, followed by a drop after about a week both in MRI (via changes in T1 baseline), and in histology (via the fluorescent tag). Histology shows HPG remains within or proximal to vasculature at early time points, but extravasates and accumulates at greater distances from vessels over time.