The Doppler spectrum indicates how the echo power is distributed according to the Doppler shift frequency. The Doppler shift frequency is directly related to the radial velocity of the scatterer.

See also Modal Velocity, Doppler Effect and Doppler Ultrasound.

From SIUI Inc.;
'Dedicated to ultrasound industry, Shantou Institute of Ultrasonic Instruments, Inc. (SIUI) has launched Apogee 3500, the Digital Color Doppler Ultrasound Imaging System.
With latest imaging technologies, high-definition image quality and excellent practical functions, the Apogee 3500 offers optimal solutions for clinical ultrasonic examination.'

'The Apogee 3500 is available with many high-density, super broadband and multi-frequency probes, such as convex, micro-convex, linear, vaginal, rectal and phased array probes, which are widely applied for different clinical diagnoses, including abdomen (liver, kidney, gall-bladder, pancreas), gynecology (uterus, ovary), obstetrics (early pregnancy, basic OB, complete OB, multi gestation, fetal echo), cardiology (adult and pediatric cardiology), small parts (thyroid, galactophore, testicles, neonate), peripheral vascular and prostate.'

The diastole is the period of relaxation in the cardiac cycle which alternates with systole. During diastole, the ventricles fill and the aortic and pulmonary valves are closed. On a Doppler spectrum analysis, diastole can be identified as beginning at the dicrotic notch (a small abrupt upswing in the deceleration phase of systole) and ending with the systolic upstroke.

See also Echocardiography and Cardiac Ultrasound.

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Hitachi Medical Systems America, Inc. (HMSA) provides a complete range of ultrasound-based systems covering the entire spectrum from compact black and white systems at entry price level up to premium class systems for the most demanding users. As a full-line supplier of medical imaging equipment in Japan, Hitachi Medical Corporation (HMC) founded HMSA to provide a direct link to the U.S. marketplace. Hitachi consolidates his distribution channels in the US by transferring the Hitachi line of Ultrasound products to HMSA in October of 2002. HMSA is responsible for the sales, marketing and service of all Hitachi Ultrasound products in the United States.

Ultrasound Systems:

The modal velocity is the frequency component which contains the most energy. In the display of the Doppler spectrum, the mode corresponds to the brightest parts of the individual spectra.