Parahydrogen‐induced polarization in imaging: Subsecond 13C angiography

Abstract

High nuclear spin polarization of ¹³C was reached in organic molecules. Enhancements of up to 10⁴, compared to thermal polarization at 1.5 T, were achieved using the parahydrogen‐induced polarization technique in combination with a field cycling method. While parahydrogen has no net polarization, it has a high spin order, which is retained when hydrogen is incorporated into another molecule by a chemical reaction. By subjecting this molecule to a sudden change of the external magnetic field, the spin order is transferred into net polarization. A ¹³C angiogram of an animal was generated in less than a second. Magn Reson Med 46:1–5, 2001.