Temporal correlation of blood scattering signals in vivo from radiofrequency intravascular ultrasound.

摘要: Abstract One limitation encountered using high frequency intravascular ultrasound (IVUS) is the echogenicity of blood, which increases dramatically at frequencies 20–40 MHz. Because higher velocity moving blood particles, echo pattern flowing shows more variations in time than that wall. To investigate time-varying characteristics scattering, measurements were performed on radiofrequency (RF) data collected vivo from five pig experiments. After positioning catheter inside iliac artery, an M-mode sequence 30 RF traces was acquired a pulse repetition rate (5 kHz). The correlation measured regions and arterial Two processing techniques, temporal averaging correlation, tested for suppression intensity. Tc region approximately 1 ms, shorter wall (Tc ⪢ 6 ms). values calculated small window showed large variation while produced constant output. eight consecutive trace (ΔT = 200 μs), method results 50% intensity reduction region. Using output as weighting function, can be further reduced to only 10% its original value. Application cross-sectional image demonstrates feasibility this technique remove most echoes enhance contrast luminal interface.