Determination of the in Vitro Limit of Detection for Pulmonary Surfactant Using Proton Magnetic Resonance Spectroscopy at 1.5T

Michael James Reeves¹, Alice E. Oates¹, David A. Capener¹, Janet E. Morris¹, Jim M. Wild¹, Martyn NJ Paley¹, Elspeth H. Whitby¹

This study examines the technical feasibility of measuring the concentration of fetal pulmonary surfactant (lecithin) by proton magnetic resonance spectroscopy using a 1.5T clinical imaging system. The lower limit of detection of lecithin in vitro was found to be around 0.5mM using typical clinical sequence parameters. This is well above the physiological concentrations found in amniotic fluid samples. Non-invasive measurement of amniotic fluid lecithin concentration by 1.5T proton magnetic resonance spectroscopy using current clinical imaging parameters is therefore not considered to be practicable.