Echo Doppler imaging

Echo has been used to assess aU levels of mechanical dyssynchrony dys-synchrony between the atrium and the ventricle, interventricular dyssynchrony, and intraventricular dyssynchrony. Echo Doppler imaging at the level of the mitral valve inflow shows the effects of a long AV interval (fused E and A waves with diastolic mitral regurgitation), short AV interval (truncation of A wave with loss of atrial kick), and optimal AV interval (aortic systolic flow starts at the end of A wave) (5,31). This is illustrated in Fig. 11.4. Pulsed-wave Doppler echocardiography has been used to evaluate interventricular dyssynchrony that is defined as the time difference between right and left ventricular pre-ejection intervals. This is usually measured from the onset of the QRS complex on the EKG (that correlates with the end of diastole) to the onset of the aortic and pulmonary ejection. Delayed aortic ejection time (>40-50ms) has been used as a marker of interventricular dyssynchrony that improves with CRT (32-34). 

Tissue Doppler imaging (TDI) which is a feature in some of the newer echo machines is a promising approach to assess dyssynchrony. It measures the time to peak systolic velocity (from the onset of QRS complex) in different segments of the LV and the delay between them is used as a marker of LV dyssynchrony (Fig. 11.6). These measurements can be obtained by pulsed-wave TDI or color-coded TDI that requires postprocessing. Initial studies used... 

The first asteroid radar data set suitable for reconstruction of the target s shape was a 2.5-hr sequence of 64 delay-Doppler images of 4769 Castalia (1989PB) (Fig. 21a), obtained two weeks after its August 1989 discovery. The images, which were taken at a subradar latitude of about 35°, show a bimodal distribution of echo power over the full range of sampled rotation phases, and least-squares estimation of Castalia s three-dimensional shape (Fig. 21b) reveals it to consist of two kilometer-sized lobes in contact. Castalia apparently is a contact-binary asteroid formed from a gentle collision of the two lobes. 

Fig. 9.7. Endometrioma with absent flow. A 34-year-old patient with chronic perimenstrual left pelvic pain. Sagittal transvaginal color Doppler sonographic image of the left ovary at day 10 of the menstrual cycle demonstrates a heterogeneous mass (between calipers) with two layers of internal low level echos, a wall calcification (arrow) and absent intracystic color Doppler flow. Pathology of the ovarian cyst diagnosed endometrioma...

An aq. soln. at 31° contains 30% a-pyr, 64% P-pyr, 2.5% a-fur, 3.5% P-fur and 0.02% aldehyde. Active ingredient of Levovist , used in echo-enhancement in sonographic Doppler-B-mode imaging. Ultrasound contrast medium. 

Itoh Y, Akamatsu K (1998) Relationships between echo level and histologic characteristics in small hepatocellular carcinomas. J Clin Ultrasound 26 295-301 Kim KW, Kim TK, Han JK, et al (2000) Hepatic hemangiomas spectrum of US appearances on gray-scale, power Doppler, and contrast-enhanced US. Korean J Radiol 1 191-197 Kim TK, Kim AY, Choi BI (2002) Hepatocellular carcinoma harmonic ultrasound and contrast agent. Abdom Imaging 27 129-138... 

---