Olaf Dietrich1, Michael Ingrisch1, Ulrike Attenberger, Michael Peller1, Konstantin Nikolaou, Maximilian F. Reiser
1Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, LMU Ludwig Maximilian University of Munich, Munich, Germany
In oxygen-enhanced MRI, a block paradigm is frequently used consisting of a series of T1-weighted scans acquired during alternating inhalation of room air and oxygen. This design results in a signal-time course for each pixel with information about lung function, respiration, and circulation. In this study, the properties of this signal-time course are studied in detail by comparing several model functions with different parameters. The optimal model function is a piecewise exponential function with different time constants for wash-in and wash-out. As a new parameter, it contains the delay between switching the gas supply and onset of the signal change.