Kelly C. McPhee1, Jennifer HE Baker1, 2, Katayoun Saatchi3, Urs O. Hfeli3, Stefan A. Reinsberg1
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada; 2Radiation Biology Unit, BC Cancer Research Centre, Vancouver, BC, Canada; 3Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
The bolus arrival time (BAT) is the time at which signal enhancement commences, following the injection of a contrast agent. Two MRI studies were performed one day apart, the first using Bayer Healthcare’s Gadovist, and the second with a high-molecular-weight contrast agent, Hyperbranched polyglycerol (HPG) derivatized with p-NH2-benzyl-DOTA. The BAT maps for the same tumour are compared to corresponding whole tumour histology sections showing necrotic and healthy tissue. Areas where BAT is delayed relative to surrounding tissue match necrotic areas in histology, with longer delays in the BAT of HPG-Gd than Gadovist. Thus, BAT is not only an important input parameter for pharmacokinetic modelling, but also a reproducible, phenomenological parameter in its own right.