Coded excitation for synthetic aperture ultrasound imaging
Coded excitation for synthetic aperture ultrasound imaging
复制标题
DOI：
10.1109/tuffc.2005.1406544
复制
发表时间：
2005-02-01
影响因子：
3.6
通讯作者：
Wang, Y
中科院分区：
文献类型：
--
作者：
O'Donnell, M;Wang, Y
峰值声功率限制了实时超声图像的信噪比 (SNR)。然而，对于大多数传统的扫描格式，平均功率远低于加热极限。这意味着使用编码激励可以显着提高 SNR。编码系统传输具有有限时间带宽乘积的宽带、时间拉长的激励脉冲。必须对接收到的信号进行解码，以产生具有改进的信噪比的成像脉冲，这是由于延长的激励中的平均功率较高而产生的。然而，解码会产生显着的距离旁瓣，从而大大降低图像质量。因此，所有实际的编码设计都代表了 SNR 增益和距离旁瓣之间的权衡。提出了一种适用于合成孔径成像的特定编码方案。在适用于血管内应用的前视成像系统上，证明了 14.5 dB 的信噪比改进和可接受的范围旁瓣。
Peak acoustic power limits the signal-to-noise ratio (SNR) of real-time ultrasound images. For most conventional scan formats, however, the average power is well below heating limits. This means the SNR can be significantly increased using coded excitation. A coded system transmits a broadband, temporally elongated excitation pulse with a finite time-bandwidth product. The received signal must be decoded to produce an imaging pulse with improved SNR resulting from the higher average power in the elongated excitation. Decoding can produce significant range side lobes, however, greatly reducing image quality. All practical coding designs, therefore, represent a trade-off between SNR gain and range side lobes. A specific coding scheme appropriate for synthetic aperture imaging is presented. A 14.5 dB SNR improvement with acceptable range side lobes is demonstrated on a forward-looking imaging system appropriate for intravascular applications.