Practical implementation and optimization of one-shot T1 imaging.

Longitudinal relaxation times (T1) can be measured rapidly in an imaging context using a "one-shot" method based on the pulse sequence originally proposed by D. C. Look and D. R. Locker (Rev. Sci. Instrum. 41, 250 1970). This sequence is significantly faster than either repeated inversion recovery or repeated saturation recovery methods. The method uses a 180 degrees inversion pulse followed by multiple small-angle alpha pulses that sample the longitudinal magnetization during its recovery. Choices of inversion pulse, tip angle, and time intervals are discussed for optimal clinical use. We can produce 29 images sampling the full T1 recovery curve with a 256 x 256 resolution in about 10 min. From this data, T1 images can be calculated with a precision of 10%.