Steady-pulsed ASL (spASL) provides high labeling efficiency and is appropriate for organs with highly pulsatile blood supply (e.g. myocardium), but quantification remains a major challenge. Here, we describe a method for quantifying tissue blood flow in spASL based on a numerical solution of the Bloch equations with flow effects. The exact acquisition timing, including irregularities generated by heart rate variability, is incorporated in this formalism. Dictionary-based quantification of blood flow is demonstrated using myocardial spASL data from healthy swine at rest.