provide a cleaner image and may make measurements more obvious The filter is used to reduce the noise that occurs from reflectors produced from walls and other structures that are within the range of the ultrasonic beam The volume button should be at the appropriate level to hear the frequencies Optimizing the Settings for Pulsed Doppler The frequency of the probe will affect the Nyquist limit of pulsed Doppler, with probes of higher frequency having a lower Nyquist limit The gain control, compress, and filter settings are similar to those described previously for continuous wave Doppler Shift of the baseline allows the entire display to be used to show either forward or reverse flow, a feature that is useful if the flow is only in one direction The scale should always be optimized and be set no higher than necessary to display the measured velocities The size of the gate should be optimized, with an increase in the sample volume increasing the strength of the signal at the expense of a lower spatial resolution In general, the smallest sample volume providing an adequate ratio of signal-to-noise should be used The update function allows for simultaneous duplex imaging to optimize the location of sampling relative to the cross-sectional image However, simultaneous cross-sectional imaging reduces the temporal resolution All pulsed Doppler traces, therefore, should be obtained with the cross-sectional image frozen Optimizing the Settings for Color Doppler This involves optimizing the gain settings, the scale, and the size of the sector The gain should be adjusted until background noise is detected in the color image and then reducing it so that the noise just disappears The scale should be adapted depending on the velocities of the flows measured When examining high velocity flow, the scale should be adapted so the maximal Nyquist limit is chosen When low velocity flow is studied, such as venous flow or flow in the coronary arteries, the scale needs to be lowered The size of the color sector needs then to be adjusted to optimize frame rates The smallest necessary size should be used Storage and Reporting of the Images Created All current echocardiographic machines allow the recording and storing of images in a digital format, which can be retrieved, viewed, and further analyzed on a digital viewing system and workstation This allows easy storage and retrieval of echocardiographic images and studies More and more centers use digital systems for reporting, which can be integrated within the reviewing stations The full digital workflow contributes to the quality and efficiency of pediatric echocardiographic laboratories.2,3 Normal Cardiac Anatomy When performing cross-sectional echocardiography, a thorough knowledge of normal and abnormal cardiac morphology is essential.4 In the normal subject, the long axis of the heart is oblique, extending more or less from the left subcostal region to the right shoulder (Fig 19.1) In addition to the long axis being oblique, the cardiac chambers, particularly the ventricles, are arranged so that the morphologically right structures are anterior to their morphologically left counterparts (see Chapter 2) The left atrium is the most posterior of the cardiac chambers Only its appendage projects to the border of the cardiac silhouette The right ventricle lies anterior to the left ventricle It swings across the front of the ventricular mass, reaching from the inferior and right-sided tricuspid valve to the anterosuperiorly and leftward positioned pulmonary valve The aortic valve is centrally located within the heart and is related to all four chambers (Fig 19.2) This central position of the aortic valve, located between the tricuspid and mitral valves, is the key to the understanding of cardiac anatomy Because of the wedged position of the aortic valve, the subaortic outflow tract interposes between the leaflets of the mitral valve and the ventricular septum Hence there are no direct attachments of the tension apparatus to the muscular septum in the left ventricle In contrast, the septal leaflet of the tricuspid valve hugs the septum (Fig 19.3) and is attached to it by tension apparatus along its length The shortaxis sections emphasize other significant differences between the right and left sides of the normal heart The arterial and atrioventricular valves in the right ventricle are separated by the supraventricular crest No such muscular crest exists in the roof of the left ventricle, where the leaflets of the aortic and mitral valves are in fibrous continuity (Fig 19.4) The subaortic outflow tract also has important relationships to the areas of atrioventricular contiguity, these being made up of two components The first, the atrioventricular membranous septum, is made of fibrous tissue, and is an integral part of the central fibrous body It interposes between the medial wall of the subaortic outflow tract and the right atrium The other area is the region of overlapping of the atrial and ventricular musculatures It exists because the septal leaflet of the tricuspid valve is attached to the septum more toward the ventricular apex than are the leaflets of the mitral valve, producing the characteristic off-setting of the valvar leaflets In the area between these valvar attachments, the walls of the right atrium overlap the base of the ventricular mass, thus forming a muscular atrioventricular sandwich (Fig ... digital systems for reporting, which can be integrated within the reviewing stations The full digital workflow contributes to the quality and efficiency of pediatric echocardiographic laboratories.2,3 Normal Cardiac Anatomy When performing cross-sectional echocardiography, a thorough knowledge of