Albrecht T, Urbank A, Mahler M, Bauer A, Doré C J, Blomley M J, Cosgrove D O, Schlief R
Department of Imaging, Hammersmith Hospital, Imperial College, School of Medicine, London, England.
Radiology. 1998 May;207(2):339-47. doi: 10.1148/radiology.207.2.9577478.
To investigate whether continuous infusion of an echo-enhancing contrast agent for up to 15 minutes can provide uniform and prolonged enhancement.
Six volunteers each received one bolus and three infusions of a microbubble contrast agent over 6-15 minutes at (a) a standard rate (mean, 2.08 mL/min), (b) a fast rate at twice the standard rate, and (c) a slow rate at half the standard rate. Spectral Doppler intensitometry of the femoral artery was performed for all infusions. Spectral Doppler ultrasound (US) scans of the femoral artery and color Doppler US scans of the carotid artery were subjectively assessed.
All infusions provided an equilibrium plateau of constant prolonged enhancement starting after 1-2 minutes and lasting until the end of the infusion. Enhancement at the plateau was +13 dB (slow rate), +17.1 dB (standard rate), and +18.3 dB (fast rate) compared with baseline. Saturation artifacts with infusions were markedly fewer than those with bolus injections. Dose effectiveness (duration of enhancement that measured at least 7.5 dB per gram of contrast agent) was markedly improved with the infusions, from 0.8 min/g for the bolus to 2.6 min/g for the slow infusion.
Continuous infusion of the microbubble contrast agent provided prolonged and uniform enhancement of Doppler signals and improved image quality by minimizing saturation artifacts.
研究持续输注增强回声造影剂长达15分钟是否能提供均匀且持久的增强效果。
6名志愿者分别接受一次团注和三次在6 - 15分钟内的微泡造影剂输注，输注速率分别为：(a)标准速率（平均2.08 mL/分钟），(b)两倍标准速率的快速率，以及(c)一半标准速率的缓慢率。对所有输注均进行股动脉频谱多普勒强度测定。对股动脉进行频谱多普勒超声（US）扫描，并对颈动脉进行彩色多普勒US扫描进行主观评估。
所有输注在1 - 2分钟后均达到持续增强的平衡平台期，直至输注结束。与基线相比，平台期的增强分别为+13 dB（缓慢率）、+17.1 dB（标准速率）和+18.3 dB（快速率）。输注时的饱和伪像明显少于团注时。输注时剂量有效性（每克造影剂至少7.5 dB的增强持续时间）明显改善，从团注时的0.8分钟/克提高到缓慢输注时的2.6分钟/克。
持续输注微泡造影剂可使多普勒信号获得持久且均匀的增强，并通过减少饱和伪像提高图像质量。
