T1-weighted images with ECG gating using partial flip angle spin-echo imaging.

K Sugimura; H Kawamitsu; K Yoshikawa; K Yuasa; T Kasai; H Okizuka

doi:10.1016/s0009-9260(05)82878-8

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T1-weighted images with ECG gating using partial flip angle spin-echo imaging.

K Sugimura·H Kawamitsu·K Yoshikawa·K Yuasa·T Kasai·H Okizuka

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Abstract

ECG-gated spin-echo imaging can reduce vascular artefacts compared with spin-echo scans without gating. However, this method produces poor T1-weighted images because the repetition time (TR) is limited by the heart rate. We investigated the value of low flip angle spin-echo imaging for increasing T1-dependent contrast when using ECG gating. Using computer simulation, the predicted contrast increased with decreasing the flip angle, and the effect was almost saturated at a flip angle of around 40 degrees. With the application of this flip angle, the identical image contrast as a T1-weighted image (TR = 400 ms) can be obtained within the heart rate range of 65 to 75 beats/min. For clinical evaluation, the tissue contrast index values ((signal intensity in the lesion-signal intensity in the muscle)2 x 100/signal intensity in the muscle) obtained by conventional spin-echo and low flip angle spin-echo imaging were compared in 17 patients. The contrast index of low flip angle spin-echo images (74.0 +/- 52.0) was significantly higher than that of conventional spin-echo images (40.9 +/- 35.9). Thus, ECG-gated low flip angle spin-echo imaging provided better T1-dependent contrast than conventional ECG-gated spin-echo imaging. This method may be especially useful for Gd-DTPA-enhanced magnetic resonance imaging.

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K Sugimura, H Kawamitsu, K Yoshikawa, K Yuasa, T Kasai, H Okizuka. 1994. T1-weighted images with ECG gating using partial flip angle spin-echo imaging.. https://doi.org/10.1016/s0009-9260(05)82878-8

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