Magnetic resonance spectroscopy to detect lecithin in amniotic fluid and fetal lung

Background: Proton magnetic resonance spectroscopy is a noninvasive technique that detects molecules within a specified region in vivo. Lecithin, the major component of surfactant, has a characteristic magnetic resonance signal, but to our knowledge, it:has never been reported in fetal lung or amniotic fluid (AF). The objective of this study was to characterize the lecithin signal in utero, which could lead to a noninvasive fetal lung; maturity test. Method: Human fetal lung and AF pockets can be identified and studied with magnetic resonance spectroscopy with the use of a 1.5-tesla Vision whole-body magnetic resonance scanner (Siemens Medical Systems; Erlangen, Germany). Spectroscopy data are collected with a single-voxel-point-resolved spectroscopy sequence. After identification of fetal anatomy with the use of scout magnetic resonance images, magnetic resonance spectroscopy of human fetal lung and AF identifies a lecithin peak. Experience: Three healthy gravidas near term were studied and lecithin peaks were identified in all. Conclusion: Lecithin can be identified in vivo with the use of volume-selected proton:magnetic resonance spectroscopy. Patient comfort and extremely short scan times suggest that refined magnetic resonance spectroscopy might be a safe, quick, and comfortable test of fetal lung maturity. (Obstet Gynecol 2000;95:457-60. (C) 2000 by The American College of Obstetricians and Gynecologists.).