FIG 2. T1 value of chloral hydrate, propofol, and CSF determined in vitro at room temperature using an inversion recovery pulse sequence at 1.5 T. T1 value of CSF is 2.32 s, of propofol is 1.86 s, and of chloral hydrate is 0.2 s. The null time of CSF is 1.6 s, of propofol is 1.3 s, and of chloral hydrate is 0.14 s