Magnetic resonance imaging of cortical bone with ultrashort TE pulse sequences
Magnetic resonance imaging of cortical bone with ultrashort TE pulse sequences
复制标题
DOI：
10.1016/j.mri.2005.02.017
复制
发表时间：
2005-06-01
影响因子：
2.5
通讯作者：
Bydder, GM
中科院分区：
文献类型：
--
作者：
Reichert, ILH;Robson, MD;Bydder, GM
目的：正常成人皮质骨具有非常短的T-2，并且特征性地不产生临床实践中常规使用的脉冲序列回波时间（TE）信号。我们希望确定是否有可能使用超短TE（UTE）脉冲序列来检测信号从皮质骨在人类subjects.Subjects和方法，使用这个信号，以summarize这个tissue. Methods：7名志愿者和10例患者进行了检查，使用超短TE脉冲序列（TE = 0.07或0.08毫秒）。短和长反转以及脂肪抑制脉冲被用作准备脉冲。还获得随后的回波图像以及通过从第一回波图像减去随后的回波图像而产生的差分图像。饱和脉冲用于T-1测量，TE逐渐增加的序列用于T-2* 测量。结果：UTE序列在儿童、正常成人和病人的皮质骨中均检测到信号。如果信噪比足够高，通常通过从第一个回波图像中减去后面的回波图像来使该信号更加明显。正常成人的平均T1为140 ~ 260 ms，平均T2 *s为0.42 ~ 0.50 ms，T1随年龄增长而显著增加（P <0.01）。短T-2信号在急性骨折中减少，在骨折畸形愈合后新骨形成时信号增加。1例骨质疏松症患者骨截面积和信号水平均降低。结论：UTE脉冲序列可在正常和异常皮质骨中检测到信号，可用于测量其T1和T2* 值以及观察对比增强情况。差分图像在增加皮质骨的显著性和观察疾病中的异常方面具有价值。(c)2005年爱思唯尔公司All rights reserved.
Purpose: Normal adult cortical bone has a very short T-2 and characteristically produces no signal with pulse sequence echo times (TEs) routinely used in clinical practice. We wished to determine whether it was possible to use ultrashort TE (UTE) pulse sequences to detect signal from cortical bone in human subjects and use this signal to characterise this tissue.Subjects and Methods: Seven volunteers and 10 patients were examined using ultrashort TE pulse sequences (TE = 0.07 or 0.08 ms). Short and long inversion as well as fat suppression pulses were used as preparation pulses. Later echo images were also obtained as well as difference images produced by subtracting a later echo image from a first echo image. Saturation pulses were used for T-1 measurement and sequences with progressively increasing TEs for T-2* measurement. Intravenous gadodiamide was administered to four subjects.Results: Signal in cortical bone was detected with UTE sequences in children, normal adults and patients. This signal was usually made more obvious by subtracting a later echo image from the first provided that the signal-to-noise ratio was sufficiently high. Normal mean adult T(1)s ranged from 140 to 260 ms, and mean T-2*s ranged from 0.42 to 0.50 ms. T-1 increased significantly with age (P < .01).Increased signal was observed after contrast enhancement in the normal volunteer and the three patients to whom it was administered. Reduction in signal from short T-2 components was seen in acute fractures, and increase in signal in these components was seen with new bone formation after fracture malunion. In a case of osteoporosis, bone cross-sectional area and signal level appeared reduced.Conclusion: Signal can be detected from normal and abnormal cortical bone with UTE pulse sequences, and this can be used to measure its T-1 and T2* as well as observe contrast enhancement. Difference images are of value in increasing the conspicuity of cortical bone and observing abnormalities in disease. (c) 2005 Elsevier Inc. All rights reserved.