![]() ![]() With QSel gradients only, lipid 1.3 ppm signalĭecreased by 300-fold compared to QSel gradients = 0 in the new sequence. Fig 3 shows dependence of lactate 1.3 ppm, lipid 0.9 ppm, 1.3 ppm and 2.0 ppm on We were able to boost lipid suppression by employing Qt1crusher. Lactate signals were similar between the two sequences (performed in a separate experiment). However, suppression of lipids at 1.3 ppm was three times less in the new sequence than the old sequence. Signals at 0.9 ppm and 2.0 ppm were similar between the two sequences. Selection gradient ratio 0:-1:2 which selects the ZQ->DQ pathway. ResultsFig 2 shows comparison of lipid signals from the previous sequence (Fig 1a) and the modified sequence (Fig 1b) with the coherence Sequence/parameters and the new sequence/parameters with a lactate phantom and an oil phantom as well as a lactate phantom placed near the typical 4 We performed comparison of the previous Sel-MQC-CSI to suppress lipid signals that might be insufficiently suppressed by Sel-MQC owing Volume saturation (VSS-OVS) bands around the region of interest in 3 4) We placed the very selective suppression outer Inversion profiles of the RF pulses were analyzed to find optimal pulse lengths by solving the BlochĮquation. As the 2.0 ppm lipid signal introduced significant baseline distortion to analyze lactate signals at 1.3 ppm, weĬarefully adjusted the RF pulse lengths to avoid excitation of one of these two The J-coupling between these lipid peaks produced MQC during the pulse train and left these peaks not adequately suppressed. (1.3 ppm) and CH peak (4.1 ppm), they excited the lipid resonances at 2.0 ppmĪnd 5.3 ppm as well. Though these pulses wereĪdequate for selective excitation/refocusing of lactate CH 3 peak 3) In the previous sequence, RF pulses of Gauss shape and 7.8 ms duration were used for both 90 oĪnd 180 o pulses. States while lipid spins experience addtional dephasing. ![]() During these nonzero gradients (indicated as Qt1crusher in Fig 1b), lactate spins remain at their zero quantum coherence Ratio of a:-1:2 or 1:b:2 where a≠0, a≠1 and b≠0, b≠-1, further suppression of lipid We found that by employing the coherence selection gradient Quantum to zero quantum transition (DQ ->ZQ) of lactate whileĭephasing lipid signals. ![]() Quantum to double quantum transition (ZQ -> DQ) or double Selection gradients with the ratio of 0:-1:2 or 1:0:2 to select either zero This removes addition and subtraction processes on Hadamard Replaced with direct slice selection on the first pulse of the Sel-MQC pulse Modifications were made from the previous sequence: 2 1) Hadamard inversion slice encoding scheme was ![]()
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