The Choice of Arterial Input Function in Perfusion-Weighted MR Imaging - Size Matters in Terms of Saturation-Like Effects

Peter Brunecker¹, Ann-Christin Ostwaldt¹, Ivana Galinovic¹, Jochen B. Fiebach¹, Martin Ebinger¹, ²

DSC-MRI is the most widely used method for perfusion imaging (PI) in brain, especially for stroke patients. However, the relationship between tracer concentration and signal change is only strictly valid for a network of capillaries and not in case of estimating the arterial input function (AIF). To investigate that impact, an analysis of 211 PI measurements regarding peak signal drop and relative concentration was performed. We found a descending linearity between the micro- and macrovascular signal with an increasing size of the AIF-defining artery. We conclude that in case of standard imaging techniques more distal arteries are preferable.