The present approach will allow investigators to correct for the relaxation-induced Lac signal loss in Sel-MQC experiments for the quantitative mapping of in vivo tumor Lac distribution. The performance of these sequences was evaluated with the use of phantoms and sub-cutaneous murine tumor models in vivo. The T2-Sel-MQC sequence incorporates a CH 3-selective 180° pulse during the MQ preparation period to overcome the J-modulation effects and allow the insertion of variable echo delays. The T1-Sel-MQC sequence combines an inversion pre-pulse with the Sel-MQC filter. As single-shot techniques they are relatively insensitive to motion artifacts. The present report investigates the feasibility of using the SelMQC method to generate maps of lactate in vivo. They allow for a very high lipid suppression efficiency. The utilization of two frequency-selective pulses tuned to the lactate methyl and methyne resonances makes the protocol highly specific for lactate, requiring no water suppression beyond the MQ filter. 7, 8, 9, 10) use magnetic field gradients to select multiple quantum coherences. Here the SelMQC technique has been combined with longitudinal Hadamard slice selection and chemical shift imaging (CSI) to yield slice-selective images of lactate. The multiple-quantum lactate editing techniques (e.g. This work reports modifications to the Sel-MQC pulse sequence, T 1-and T2-Sel-MQC, that facilitate relaxation measurements of Lac. In this study, we designed two pulse sequences that eliminate such phase differences of lactate and alanine while suppressing lipid signals by modifications of the Selective Multiple. PMID: 15389963 DOI: 10.1002/mrm.20206 Abstract The frequency-selective multiple-quantum-coherence (Sel-MQC) lactate (Lac) filter offers complete lipid and water suppression in a single scan for robust in vivo detection of tumor Lac, even in the presence of abundant lipids. The double selective multiple quantum filter technique (SelMQC) has been shown to be effective for nonlocalized detection of lactate with little or no interference from other signals. Conversion of the detected signal into accurate tissue concentrations of Lac requires knowledge of in vivo Lac T1 and T2 relaxation times. double quantum coherence transfer selection gradients were each 3 msec half sinusoidal with. The frequency-selective multiple-quantum-coherence (Sel-MQC) lactate (Lac) filter offers complete lipid and water suppression in a single scan for robust in vivo detection of tumor Lac, even in the presence of abundant lipids. (selective coherence transfer/lactic acid/spectral editing). This study presents the use of a selective homonuclear multiple quantum coherence transfer sequence (SelMQC-CSI), at 1.5 T, to better quantify lactate in the presence of lipids. In vivo tumor lactate relaxation measurements by selective multiple-quantum-coherence (Sel-MQC) transfer
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