Temporal correlation of blood scattering signals in vivo from radiofrequency intravascular ultrasound
| Autor: | A.F.W. van der Steen, Elma J. Gussenhoven, Wenguang Li, Jan Honkoop, C.T. Lancee, Nicolaas Bom |
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| Rok vydání: | 1996 |
| Předmět: |
Pathology
medicine.medical_specialty Materials science Acoustics and Ultrasonics Radiological and Ultrasound Technology medicine.diagnostic_test Swine Scattering Pulse (signal processing) Echo (computing) Biophysics Hemodynamics Echogenicity Iliac Artery Intensity (physics) Circulatory system Intravascular ultrasound Image Processing Computer-Assisted medicine Animals Radiology Nuclear Medicine and imaging Blood Flow Velocity Ultrasonography Interventional Biomedical engineering |
| Zdroj: | Ultrasound in Medicine & Biology. 22:583-590 |
| ISSN: | 0301-5629 |
| DOI: | 10.1016/0301-5629(96)00023-3 |
| Popis: | One limitation encountered using high frequency intravascular ultrasound (IVUS) is the echogenicity of blood, which increases dramatically at frequencies of 20-40 MHz. Because of the higher velocity of moving blood particles, the echo pattern of flowing blood shows more variations in time than that of the wall. To investigate the time-varying characteristics of the blood scattering measurements were performed on the radiofrequency (RF) data collected in vivo from five pig experiments. After positioning the echo catheter inside the iliac artery, an M-mode sequence of 30 RF traces was acquired at a high pulse repetition rate (5 kHz). The RF correlation time was measured on the regions of blood and the arterial wall. Two processing techniques, temporal averaging and correlation, were tested for suppression of the blood echo intensity. The correlation time Tc measured in the blood region was approximately 1 ms, which was shorter than that measured in the wall region (Tc6 ms). The correlation values calculated in a small window showed a large variation in the blood region while the wall region produced a constant high output. After processing eight consecutive RF traces (delta T = 200 microseconds), the temporal averaging method results in a 50% intensity reduction in the blood region. Using the correlation output as a weighting function, the blood echo intensity can be further reduced to only 10% of its original value. Application of the RF correlation processing to a cross-sectional image data demonstrates the feasibility of this technique to remove most of the blood echoes and enhance the image contrast of the luminal interface. |
| Databáze: | OpenAIRE |
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