Keyhole Chemical Exchange Saturation Transfer

Gopal Varma¹, Robert E. Lenkinski¹, Elena Vinogradov¹

Contrast from chemical exchange saturation transfer (CEST) often requires multiple acquisitions. The keyhole technique is implemented that combines low-resolution data acquired at different saturation frequencies with a high-resolution reference image. CEST images reconstructed using the keyhole technique are compared with those obtained using standard acquisition at the same resolution and are shown to produce a comparable contrast for gagCEST. In particular, a keyhole image shows distinction of a cartilage sample from its surroundings that is not visible from the low-resolution data alone. Thus keyhole CEST provides a detectable contrast with significant reduction in acquisition time of the complete dataset.