T1 measurement using a short acquisition period for quantitative cardiac applications.

Myocardial signal intensity curves for myocardial perfusion studies may be made quantitative by the use of T1 measurements made after the first-pass of contrast agent. A short data acquisition method for T1 mapping is presented in which all data for each T1 map are acquired in a short breath hold, and the slice geometry and timing in the cardiac cycle exactly match that of the dynamic first-pass perfusion sequence. This allows accurate image registration of the T1 map with the first-pass series of images. The T1 method is based on varying the preparation-pulse delay time of a saturation recovery sequence, and in this implementation employs an ECG-triggered, single-shot, spoiled gradient echo technique with SENSE reconstruction. The method allows T1 estimates of three slices to be made in fifteen heartbeats. For a range of samples with T1 values equivalent to those found in the myocardium during the first-pass of contrast agent, T1 estimates were accurate to within 6%, and the variation between slices was 2% or less.