Spin echo imaging is the most widely used method for T2-weighted Magnetic Resonance Imaging. However, long scan times with spin echo imaging have prompted the development of alternative methods such as Fast Spin Echo (FSE), which acquires a similar image in a fraction of the time. One drawback to FSE is that the signal from lipids is especially bright, an artifact which can hinder the detection of pathology. Another more important drawback is its insensitivity to small areas of iron, making the diagnosis of hemorrhage more difficult. We have been investigating a variation of FSE that addresses these issues. Methods and Results The new dual echo FSE sequence allows the lipid signal to decay via J-coupling midway through the echo train. As a result, the late echo images display lower fat signal as compared to conventional FSE. Images of a normal volunteer showed decreased lipid signal around the scalp and eyes. The new FSE sequence is also more sensitive to iron, as shown in a patient study. In this study, signal loss is seen in areas of hemorrhage in both the conventional T2-weighted sequence and in the modified FSE sequence. Discussion Our modification to the FSE sequence removes the two greatest drawbacks to the widespread use of PSE sequences in clinical imaging. Lipid signal is effectively reduced and areas of hemorrhage arc detectable. The new FSE sequence is also more sensitive to iron, as shown in a patient study. In this study, signal loss is seen in areas of hemorrhage in both the conventional T2-weighted sequence and in the modified FSE sequence.
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