Proton Detection of Choline and Lactate in EMT6 Tumors by Spin-Echo-Enhanced Selective Multiple-Quantum-Coherence Transfer

An extension of the Sel-MQC pulse sequence—SEE-SelMQC (spin-echo-enhanced selective multiple-quantum coherence transfer)—that completely suppresses lipid and water in tissues containing mobile lipid in a single scan and detects¹H resonances of multiple metabolites is described. As in the Sel-MQC lactate-editing experiments [Q. Heet al., J. Magn. Reson. B106, 203 (1995)], SEE-SelMQC acquires lactate from its ZQ → DQ coherence-transfer pathway; in addition, the method recovers signal from other metabolites by selective generation of additional spin echoes using extra frequency-selective pulses and gradients. This method introduces no loss of lactate signal intensity beyond the 50% that is lost through the multiple-quantum coherence-transfer process. The spatial distributions of choline and lactate with a phantom andin vivo,in subcutaneously implanted murine EMT6 tumors, have been simultaneously mapped.