ESC Textbook of Cardiovascular Imaging - sample

standardized data acquisition in transthoracic echocardiography 9
Fig. 1.8 Display of a standardized M-mode sweep (a). The correct transducer position is documented by the M-mode sweep by a horizontal line between
the ventral border of the anteroseptal septum and the ventral border of the aortic root (dotted line). Short-axis views are defined by the accurate cross-section
through the left ventricular attachment of the papillary muscles (b), through the papillary muscles (c), through the chord heads as well as the chord strands (d),
through the mitral valve (e), through the inter-atrial septum and the left ventricular outflow tract (f), through the aortic valve (g), the aortic root and the proximal
ascending aorta (h), as well as by a nearly longitudinal plane through the pulmonary trunk and the bifurcation of the pulmonary arteries (i). The red arrows show
the position of the respective short-axis view in a M-mode sweep. Additional comments in the text.
heads, as well as the chord strands ( Fig. 1.8d), through the
mitral valve ( Fig. 1.8e), through the inter-atrial septum and
the left ventricular outflow tract ( Fig. 1.8f), through the
aortic valve ( Fig.1.8g), the aortic root and the proximal ascending
aorta ( Fig. 1.8h), as well as by a nearly longitudinal
plane through the pulmonary trunk and the bifurcation of the
pulmonary arteries ( Fig. 1.8i). The acquisition of a correct
M-mode sweep is performed within 6–12 cardiac cycles using
the cursor in the centre line of all parasternal short-axis views
by scanning through the left ventricle over the long axis of the
left ventricle by tilting the transducer starting from the shortaxis
view between the papillary muscles up to the cranial shortaxis
view of the centrally intersected aortic valve and ascending
aorta ( Fig. 1.8a). By deriving M-modes and M-mode sweeps
in the short axis, it can always be checked whether the left heart
is sliced exactly in its centre line or only a secant view of the
left ventricle is documented. This fact favours the acquisition
of M-modes using short-axis views instead of a long-axis view.
The correct transducer position is documented in the M-mode
sweep by a horizontal line between the border of the ventral septum
and the border of the ventral ascending aorta. The alternative
to document the correct transducer position in the long-axis
view simultaneously to the short-axis views is only possible by
biplane scanning. The problem of isolated short-axis views is the
fact that the transducer position is too much lateral or caudal,
which causes an oval conformation of the ventricular wall at the
level of the left ventricle. The consequence for measurements of
left ventricular dimensions and wall thicknesses is that the left
ventricular cavity is measured too large and the ventricular wall
is measured too thick ( Fig. 1.9).
For training aspects and to document manual skills of targetoriented
scanning, the correct acquisition of the M-mode sweep
should be integrated into the educational process like a driver’s
license for echocardiography. For clinical practice the correct
M-mode sweep represents a characteristic profile of the individual
human heart.
According to European recommendations, however, it is not
mandatory to acquire the M-mode sweep. The standard documentation
includes only parasternal short-axis views at the midpapillary
level, at the mitral valve level and at the aortic level. In
all parasternal short-axis views the centre of the left ventricle
or the aortic valve should be in the middle of the scanning sector.
Near the transducer the parasternal short-axis view at the
mid- papillary level ( Fig. 1.10a–d) shows the free right ventricular
wall, the right ventricular cavity, all mid-segments of
the left ventricular wall (near the transducer: anteroseptal—0°;