Fellner F, Held P, Fellner C, Schmitt R, Obletter N
Department of Diagnostic Radiology, Friedrich-Alexander-University of Erlangen-Nurnberg, Erlangen, Germany.
Magn Reson Imaging. 1997;15(5):517-24. doi: 10.1016/s0730-725x(97)00003-9.
In this prospective study two different T2-weighted fast spin-echo (FSE) sequences and a gradient- and spin-echo (GRASE) sequence were compared in 20 consecutive patients undergoing clinical pelvic MR examinations. A GRASE and two FSE sequences were applied, whereby the FSE sequences differed from each other by altered echo spacings (15.0 and 22.5 ms) and T2 contrast. Quantitative image analysis included ROI evaluation of different S/N and C/N values. Visual image analysis was performed by two independent readers using a standardized score sheet for anatomic and pathologic findings. Overall image quality was significantly better in both FSE sequences. GRASE and FSE22.5 were superior in delineation of most of anatomic and pathologic structures due to intermediate to hypointense contrast behavior of pelvic fat compared to FSE15.0 in which fat was bright. Therefore, FSE15.0 was optimal for low intensity lesions. Short acquisition times of FSE and GRASE sequences allow application of two different techniques-fat hypointense respectively bright-for excellent lesion visualisation. This study demonstrates the usefulness of contrast manipulation in fast T2-weighted MRI techniques without special techniques, such as fat saturation.
在这项前瞻性研究中，对20例连续接受临床盆腔磁共振检查的患者，比较了两种不同的T2加权快速自旋回波（FSE）序列和一种梯度与自旋回波（GRASE）序列。应用了一种GRASE序列和两种FSE序列，其中FSE序列在回波间隔（15.0和22.5毫秒）和T2对比度方面彼此不同。定量图像分析包括对不同信噪比（S/N）和对比噪声比（C/N）值的感兴趣区（ROI）评估。由两名独立阅片者使用标准化评分表对解剖和病理表现进行视觉图像分析。两种FSE序列的总体图像质量均显著更好。由于盆腔脂肪在GRASE序列和FSE22.5序列中呈中等至低信号对比表现，与脂肪呈高信号的FSE15.0序列相比，GRASE序列和FSE22.5序列在显示大多数解剖和病理结构方面更具优势。因此，FSE15.0序列对低强度病变最为理想。FSE序列和GRASE序列的采集时间短，可分别应用两种不同技术——脂肪低信号和脂肪高信号——以实现出色的病变可视化。本研究证明了在快速T2加权磁共振成像技术中，无需脂肪饱和等特殊技术进行对比度操控的有用性。
