Caleb Roberts1,2, Sarah Hughes3, Josephine H. Naish1,2, Katherine Holliday1,2, Yvonne Watson1,2, Sue Cheung1,2, Giovanni A. Buonaccorsi1,2, Helen Young4, Noel Clarke3,5, Geoff J. M. Parker1,2
1Imaging Science & Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 2Biomedical Imaging Institute, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 3Paterson Institute for Cancer Research, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 4AstraZeneca, Macclesfield, Cheshire, United Kingdom; 5Department of Urology, Salford Royal Hospital NHS Foundation Trust, Salford, Greater Manchester, United Kingdom
An important influence on DCE-MRI tracer kinetic parameters that is commonly overlooked is the hematocrit (Hct), which relates the measured whole blood contrast agent concentration to the blood plasma contrast agent concentration, thereby influencing the arterial input function, Ktrans and vp. We investigate the errors in these parameters when using an assumed Hct rather than an individually measured Hct, which in this study was obtained at each DCE-MRI visit. Our findings have important implications for clinical trials where a treatment effect may be masked due to unaccounted for fluctuations in patients Hct throughout a course of therapy.