Postert T, Federlein J, Rose J, Przuntek H, Weber S, Büttner T
Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, Germany.
J Neuroimaging. 2001 Jan;11(1):18-24. doi: 10.1111/j.1552-6569.2001.tb00004.x.
The present study was designed to provide normal data of transient response second harmonic imaging (TRSHI) examinations of cerebral echo contrast enhancement using different modes of electrocardiogram (ECG) gating and echo-contrast agent doses.
Fifty-five patients were examined in an axial diencephalic plane of section using the transtemporal acoustic bone window. TRSHI examinations (ECG gating: systolic, frame-rate once every 2 cardiac cycles = "basical instrument setting") could be performed in 50 individuals with adequate insonation conditions after application of 4 g of a galactose-based microbubbles suspension in a concentration of 400 mg/ml. For comparison, diastolic ECG gating (20 patients), cardiac-cycle triggering frequency of once every 2 seconds (15 patients), or an echo contrast agent dose of 2 g Levovist (15 patients) were used. Analysis of peak intensities (PIs) and areas under the curve (AUCs) was done in posterior (region of interest [ROI]a) and anterior (ROIb) parts of the thalamus, in the lentiform nucleus (ROIc), and the white matter (ROId).
In 41 patients with basical instrument setting, characteristic time intensity curve (TIC) could be detected in all ROIs. In ROIa (90%) and ROIb (82%), focal contrast enhancement was most difficult to visualize, and in ROIc and ROId, characteristic TICs were observable in more than 90% of the examinations. Background subtracted PIs and AUCs were significantly higher in ROIc (mean PI: 12.2 +/- 8 acoustic units [AUs]; mean AUC: 598.8 +/- 451.1 AU x Cardiac cycles), and ROId (11.8 +/- 6.9; 559.2 +/- 404) as compared to ROIa (8.3 +/- 5.2; 368.9 +/- 242.7) and ROIb (7.1 +/- 4.7; 298.2 +/- 199.1) (P < .0001). Values for corresponding examinations with a diastolic ECG gating and a cardiac cycle triggering frequency of once every 2 seconds were not different as compared to the basical instrument setting. A 4 g Levovist dose increased the portion of typical TIC in all ROIs. PI of 4 g examinations were significantly higher in ROId and ROIb as compared to the 2 g examination.
Our findings indicate that TRSHI allows noninvasive assessment of focal cerebral contrast enhancement in the majority of patients with adequate insonation conditions. This study provides data about normal quantitative and qualitative TRSHI values in patients without cerebrovascular diseases. A dose of 4 g Levovist is recommended in those individuals with inaccurate echo contrast enhancement using the 2 g dose.
本研究旨在提供使用不同模式的心电图（ECG）门控和超声造影剂剂量进行脑回声对比增强的瞬态响应二次谐波成像（TRSHI）检查的正常数据。
55例患者在经颞骨声窗的轴位间脑平面进行检查。在50例声窗条件良好的个体中，静脉注射4g浓度为400mg/ml的基于半乳糖的微泡混悬液后，采用TRSHI检查（ECG门控：收缩期，每2个心动周期采集1帧图像 = “基本仪器设置”）。作为对照，采用舒张期ECG门控（20例患者）、每2秒触发1次心动周期（15例患者）或2g声诺维超声造影剂剂量（15例患者）。对丘脑后部（感兴趣区[ROI]a）、前部（ROIb）、豆状核（ROIc）和白质（ROId）的峰值强度（PI）和曲线下面积（AUC）进行分析。
在41例采用基本仪器设置的患者中，所有感兴趣区均可检测到特征性时间强度曲线（TIC）。在ROIa（90%）和ROIb（82%）中，局灶性对比增强最难观察到，而在ROIc和ROId中，超过90%的检查可观察到特征性TIC。与ROIa（8.3±5.2；368.9±242.7）和ROIb（7.1±4.7；298.2±199.1）相比，背景扣除后的PI和AUC在ROIc（平均PI：12.2±8声学单位[AUs]；平均AUC：598.8±451.1 AU×心动周期）和ROId（11.8±6.9；559.2±404）中显著更高（P <.0001）。与基本仪器设置相比，舒张期ECG门控和每2秒触发1次心动周期的相应检查值无差异。4g声诺维剂量增加了所有感兴趣区典型TIC的比例。与2g检查相比，4g检查的ROId和ROIb的PI显著更高。
我们的研究结果表明，在大多数声窗条件良好的患者中，TRSHI可用于无创评估局灶性脑对比增强。本研究提供了无脑血管疾病患者正常的TRSHI定量和定性数据。对于使用2g剂量超声造影剂时回声对比增强不准确的个体，建议使用4g声诺维剂量。
