 |
| Fig. 21 |
The long-axis section is familiar to those who have experience of
M-mode echocardiography. As shown in Fig.
21, it contains the following structures.
At the top is the outflow portion of the right ventricle, below
which the plane cuts across the anterior portion of the interventricular
septum. The aortic root is seen at the right, with the right coronary
(upper) and noncoronary (lower) cusps of the aortic valve. Below
the aortic root is the left atrium. To the left of the section is
the apex of the left ventricle, in which the posteromedial papillary
muscle can be seen. Separating the left atrium from the left ventricle
is the mitral valve. The longer, anterior leaflet arises from the
posterior wall of the aortic root, and the shorter, posterior leaflet
is attached at the atrioventricular groove; the plane cuts across
the coronary sinus at this point.
 |
| Fig. 22-23 |
The ultrasound image (Figs.
22-24) through encompasses the region from the papillary muscles
to the aortic valve. It clearly shows the motion of the aortic
and mitral valves and permits measurement of the left atrial and
aortic root dimensions, as well as those of the left ventricular
cacity, interventricular septum, and posterior ventricular wall.
 |
| Fig. 24 |
This view is used for many purposes, including all types of
left ventricular outflow obstruction, mitral and aortic valve
vegetations, and mitral valve prolapse. It corresponds approximately
to the angiographic right anterior oblique view, but reversed
right-to-left. Superior angulation of the transducer allows the
scan plane to be extended up to the roof of the left atrium and
the proximal part of the ascending aorta, which is useful for
detecting atrial masses and for aortic root dissection and aneurysms.
However, the parasternal long-axis view cannot normally be used
to visualize the apical region of the left ventricle, since attempts
to angle the scan toward the apex are thwarted by the presence
of lung tissue.
 |
| Figs. 25-26 |
With counterclockwise rotation of the transducer and slight medial
angulation, the right atrium, tricuspid valve apparatus, and proximal
portion of the right ventricular inlet are encountered. This is
termed the right ventricular inlet view (Figs.
25 and 26).
2004