The suprasternal view, also known as the suprasternal notch view, is obtained by placing the ultrasound probe in the suprasternal notch, pointing inferiorly and slightly posteriorly toward the mediastinum. The probe is placed with the marker towards the chin.
In this view, we visualize the aortic arch in its long axis (or short axis if the probe is turned 90 degree clockwise), allowing assessment of:
The transverse aortic arch and its curvature.
The brachiocephalic vessels branching off the arch: the innominate artery, left common carotid, and left subclavian artery. The branching usually takes place towards the right shoulder in a left-sided aorta.
The descending aorta, visualized as a continuation of the arch.
The pulmonary artery bifurcation if angled appropriately.
This view is particularly useful for evaluating aortic arch sidedness, identifying aortic coarctation, arch hypoplasia, vascular rings, and for confirming patency and flow direction through the aortic arch and descending aorta using color and spectral Doppler. In neonates and infants, where transthoracic windows are often optimal, the suprasternal view provides critical anatomical and functional information about the systemic outflow tract. It is also a good area to interogate the ductus arteriosus.
Suprasternal view allows for visualization of the aortic arch, measurement of the ascending, descending and transverse arch. It is also the opportunity to evaluate for coarctation, hypoplastic arch or presence of a posterior shelf leading to obstruction. PW Doppler may be obtained in the pre and post-ductal aorta, as well as in the ascending aorta. The angulation is optimal for assessing aortic stenosis CW-Doppler.
B-Mode of the Aortic Arc (Ascending, transverse and descending). The origin of the brachiocephalic trunk, the left carotid and left subclavian artery can be visualized.
Colour box outlines that there is no sign of turbulence of acceleration.
Another example of an arch view with the corresponding colour box
Arch view and colour
Other examples of arch views with B-Mode and Colour
It is important to visualize and "open" the isthmus. It is often hard to tell if there is a narrowing in the presence of a patent ductus. As such, if the isthmus is narrowed, or if there is diffuse decrease in the caliber of the aorta, it is important to monitor clinically, as well as to ascertain ductal closure and arch caliber / diameters once ductus is closed. By quick rule of thumb, the isthmus diameter should be at least (if not bigger) than the weight of the baby in mm (example: 3kg = more than 3 mm). Best practice is to measure and to evaluate Z-scores of diameters based on normative tables. More on normative values here.
It is important to visualize the origin of the neck vessels—the brachiocephalic artery, left carotid artery, and left subclavian artery—as arising from the aortic arch. Occasionally, a normal variant is observed in which the left carotid and left subclavian arteries share a common origin. This is sometimes referred to as a "bovine arch," although the term is a misnomer, as bovines do not actually have this vascular configuration.
B-mode and Colour simultaneously. The ishmus is well defined. We are aligned as well to obtain a CW-Doppler at the isthmus level if there was a concern for a coarctation. In hypoplastic aortic arch, CW-Doppler may be less reliable as there is a multi-stage narrowing and not a discreet narrowing.
Cursor is placed in the ascending aorta. By colour flow, we can observe the ascending filling, transverse colour flow and descending aortic flow.
Doppler in the ascending aorta outlining forward flow without acceleration. This view is optimal to obtain the CW-Doppler as well when there are signs of aortic valve stenosis, in order to estimate the gradient through the LVOT. It is also important to evaluate whether there is a component of retrograde filling of the arch when there is significant aortic stenosis or low LV output.
Here we are in the descending aorta, near the transverse arch. It is expectd that we are before the ductus arterosis, although important to visualize where the ductus connects to the arch as there are variable anatomies. Here we are obtaining a PW-Doppler of the descending aorta (pre-ductal). In this particular case, the ductus has already closed.
PW-Doppler of the descending aorta. Here we are in a zone expected to be after the ductus. An important area to evaluate for retrograde flow in the post-ductal aorta.
Pre-ductal descending aorta indicating forward flow in systole and diastole.
Post-ductal descending aorta PW-Doppler indicating reversal of flow during diastole (left to right ductus arteriosus leading to diastolic steal effect). Here we trace the VTI.
If you turn the probe 90 degree with the marker towards the left shoulder, you will obtain a cross-section of the ascending aorta and often the bifurcation of the pulmonary artery into the right and left pulmonary arteries ("Mustache view" or "pants view").
B-mode of the branching of the pulmonary artery. The RPA and LPA diameters are typically measured at the bifurcation as the largest diameter.
Simultaneous B-Mode and Colour Mode. This is an important view to make sure there is no acceleration in one of the pulmonary arteries (could be secondary to stenosis, flow, or angulation of the pulmonary artery - especially in newborns).
Peripheral pulmonary stenosis (PPS) in newborns refers to narrowing or reduced caliber of the branch pulmonary arteries, typically involving the right and/or left pulmonary artery beyond the bifurcation of the main pulmonary artery. It is a common and usually benign finding in neonates, especially in preterm or low birth weight infants.Physiologic PPS is often seen in healthy newborns due to the angulation of the branching of the pulmonary arteries, which become more linear with growht (reducing the angle of branching). On echocardiography, PPS is characterized by flow acceleration with mild turbulence in the branch pulmonary arteries on color Doppler and elevated velocities (typically 1.5–2.0 m/s) on spectral Doppler.
Cursor in the right pulmonary artery (RPA).
Cursor in the left pulmonary artery (LPA).
PW-Doppler in the LPA. Less than 2 m/sec (200 cm/s)
PW-Doppler in the RPA. Less than 2 m/sec (200 cm/s).
It is important to evaluate the bifurcation of the first vessel (brachiocephalic) to ensure a bifurcation towards the right side - left sided arch. In the presence of a right-sided arch, one may need to further delineate if there is presence of a vascular ring.
Cross-sectional view of the brachiocephalic trunk coming off the aorta, eventually branching into the right carotid and right subclavian artery while we are fanning the ultrasound probe towards the right shoulder of the baby. This corresponds to normal expected branching with a left sided arch.
This view is also useful to assess SVC flow and presence of catheter's position in the upper limb entering the right atrium via the SVC.
Reference: Normative Values of Aortic Arch Structures in Premature Infants. J Am Soc Echocardiogr 2017;30:227-32.)
From: Recommendations for Quantification Methods During the Performance of a Pediatric Echocardiogram: A Report From the Pediatric Measurements Writing Group of the American Society of Echocardiography Pediatric and Congenital Heart Disease Council. Lopez L. et al. J Am Soc Echocardiogr 2010;23:465-95.