Seidel G, Greis C, Sonne J, Kaps M
Department of Neurology, Medical University at Lübeck, Germany.
J Neuroimaging. 1999 Jul;9(3):171-4. doi: 10.1111/jon199993171.
Harmonic imaging increases the signal-to-noise ratio in grey-scale imaging. With the use of ultrasound contrast agents (UCA), imaging of brain perfusion seems possible. The authors used an ultrasound system in connection with a 1.8/3.6-MHz harmonic sector transducer and an acoustic densitometry unit for quantification of ultrasound intensity in the thalamus (THAL), the temporoparietal white matter (TPWM), and the lateral fissure (LF). Ten milliliters of BY963, a spherosome-air-based UCA, was injected intravenously in 12 healthy volunteers. Time-intensity curves were calculated. Mean increase of intensity (standard deviation [SD]), mean area under the time-intensity curve (AUC) from baseline (SD), and mean transit time (MTT) (SD) in the region of LF, THAL, and TPWM were 2.2 +/- 1.7, 1.1 +/- 0.6, 0.9 +/- 0.9 dB and 16.7 +/- 22.7, 4.7 +/- 4.7, 3.7 +/- 6.3 as well as 11.1 +/- 3.5, 9.7 +/- 3.1, and 11.9 +/- 8.0, respectively. There was a statistically significant difference for mean AUC (p = 0.02) but none comparing mean intensity increase (p = 0.07) and MTT (p = 0.9). The authors' study indicates that different regions of the human brain show different time-intensity curves. These results suggest that it is possible to measure parameters closely related to perfusion in various regions of the adult human brain.
谐波成像可提高灰阶成像中的信噪比。使用超声造影剂（UCA）后，脑灌注成像似乎成为可能。作者使用了一台超声系统，该系统与一个1.8/3.6兆赫的谐波扇形换能器以及一个声学密度计单元相连，用于定量丘脑（THAL）、颞顶叶白质（TPWM）和外侧裂（LF）中的超声强度。在12名健康志愿者中静脉注射了10毫升基于脂质体-空气的UCA——BY963。计算了时间-强度曲线。LF、THAL和TPWM区域的强度平均增加值（标准差[SD]）、从基线开始的时间-强度曲线下平均面积（AUC）（SD）以及平均通过时间（MTT）（SD）分别为2.2±1.7、1.1±0.6、0.9±0.9分贝以及16.7±22.7、4.7±4.7、3.7±6.3以及11.1±3.5、9.7±3.1和11.9±8.0。平均AUC存在统计学显著差异（p = 0.02），但比较平均强度增加值（p = 0.07）和MTT（p = 0.9）时无显著差异。作者的研究表明，人类大脑的不同区域显示出不同的时间-强度曲线。这些结果表明，测量与成人大脑各区域灌注密切相关的参数是可能的。
