Dousset M, Weissleder R, Hendrick R E, Stark D D, Fretz C J, Elizondo G, Hahn P F, Saini S, Ferrucci J T
Department of Radiology, Massachusetts General Hospital, Boston.
Radiology. 1989 May;171(2):327-33. doi: 10.1148/radiology.171.2.2704797.
Magnitude-reconstructed short inversion-time (TI) inversion-recovery (IR) sequences have the advantage of reducing the signal of fat while providing additive T1 and T2 contrast. A double-echo short TI IR sequence was implemented to offer different degrees of T1- and T2-dependent image contrast. In 50 consecutive patients with proved liver tumors (30 metastases, 13 hemangiomas, seven other primary liver tumors), images obtained with a double-echo IR sequence at a repetition time (TR) of 1,500 msec, echo time (TE) of 30 and 60 msec, and TI of 80 msec (TR/TE/TI = 1,500/30, 60/80) were compared with those obtained with spin-echo (SE) sequences at a TR of 275 msec and a TE of 14 msec (TR/TE = 275/14) and 2,350/60, 120, 180. Metastases-liver contrast-to-noise ratios were highest at SE 275/14, followed by IR 1,500/30/80 and SE 2,350/180. IR 1,500/30/80 and SE 275/14 sequences consistently showed higher sensitivity for the detection of metastases than T2-weighted SE sequences. Differential diagnosis of benign and malignant lesions was more reliable with T2-weighted SE sequences than T2-weighted short TI IR sequences.
幅度重建的短反转时间（TI）反转恢复（IR）序列具有在提供附加的T1和T2对比的同时降低脂肪信号的优点。实施了双回波短TI IR序列以提供不同程度的T1和T2依赖性图像对比。在50例经证实患有肝脏肿瘤的连续患者中（30例转移瘤、13例血管瘤、7例其他原发性肝脏肿瘤），将在重复时间（TR）为1500毫秒、回波时间（TE）为30和60毫秒、TI为80毫秒（TR/TE/TI = 1500/30, 60/80）时用双回波IR序列获得的图像与在TR为275毫秒、TE为14毫秒（TR/TE = 275/14）以及2350/60、120、180时用自旋回波（SE）序列获得的图像进行比较。转移瘤与肝脏的对比噪声比在SE 275/14时最高，其次是IR 1500/30/80和SE 2350/180。IR 1500/30/80和SE 275/14序列对转移瘤的检测始终显示出比T2加权SE序列更高的敏感性。与T2加权短TI IR序列相比，T2加权SE序列对良性和恶性病变的鉴别诊断更可靠。
