Quantification of Myocardial Blood Flow in the Presence of Remaining Contrast Agent - a Simulation Study

INTRODUCTION Quantification of myocardial blood flow (MBF) using first-pass dynamic contrast enhanced (DCE) MRI is based on the relationship between signal intensity (SI) and concentration of administered contrast agent (CA). In general, in measurements of MBF this relationship is assumed to be linear, but in reality it is more complex. Therefore, residual CA from previous injections remaining in the blood also influences the relationship between SI and concentration of CA by increasing the baseline of the current DCE-MRI measurement. The concentration of residual CA depends, among other factors, on the renal clearance time of CA, which is normally much longer [1] than the interval between two perfusion measurements. These two factors, the nonlinearity of relationship and its dependency on the residual CA, lead to errors in evaluated signal time-courses and in consequence to a faulty quantification of MBF. The aim of this simulation study was to investigate the error of quantified MBF caused by the nonlinearity of the relationship between SI and concentration of CA and to analyse the error induced by residual CA.