Variation of contrast between different brain tissues with an MR snapshot technique.

The lack of tissue contrast in gradient-echo sequences with very short repetition times can be overcome by using a single inversion pulse prior to the entire imaging sequence. The contrast can be changed by variation of the time delay between the inversion pulse and the first excitation. This snapshot technique was introduced for very fast acquisition of images, but it also provides images with a strong contrast of gray to white matter and of brain tissue to cerebrospinal fluid. The authors designed a sequence that allows sufficient spatial resolution and good image quality. The measurement time is 1.2 seconds, and the in-plane resolution is 0.8 mm. A large variation in contrast with different inversion times was demonstrated on brain images of volunteers and patients.