Transthoracic Echocardiography: Acquisition Protocol

A complete transthoracic echocardiogram (TTE) is more than a sequence of good-looking images — current guidelines define a specific checklist of 2D clips, M-mode tracings, and Doppler measurements that together constitute a comprehensive study. This page covers that checklist, organized by transducer window, along with the defined limited/focused exam protocols used for specific clinical questions. For the view-by-view technique of how to obtain each image — including transducer marker orientation — see the Views & Tips for Optimal Imaging tutorial.

Comprehensive vs. Limited Examinations

A comprehensive TTE addresses all four chambers, all four valves, the pericardium, and the great vessels, and is the default study type. A limited (or problem-focused) exam addresses a single area of the heart or answers a single clinical question — for example, pericardial effusion follow-up or a rapid assessment of LV function. Three defined limited protocols cover the most common scenarios:

• Limited exam for pericardial effusion — PLAX and subcostal windows, focused on effusion size, location, and hemodynamic signs of tamponade
• Limited exam for LV function — parasternal and apical windows sufficient to estimate LV size and ejection fraction, without the full valve and hemodynamic workup
• Limited exam for RV/pulmonary hypertension screening — RV-focused apical and parasternal views, TR jet velocity, and IVC assessment, targeted at the specific hemodynamic questions RV and PH evaluation requires

A limited study report should still comment on every structure actually visualized — not only the ones directly relevant to the indication — and should reference when the most recent comprehensive study was performed, so the reader understands the context the focused exam sits within. Redundant restatement of the prior comprehensive study’s findings should be avoided, but any new incidental finding should still be reported.

The Acquisition Checklist, by Window

Parasternal Long-Axis (PLAX)

• 2D clips at both increased and optimized depth
• Linear measurements: RV internal dimension, interventricular septal thickness, LV internal dimension (diastole and systole), LV posterior wall thickness, LA anteroposterior dimension
• M-mode through the aortic valve, mitral valve, and LV
• Zoomed grayscale and color clips of the LVOT/aortic valve and of the mitral valve, with LVOT and aortic annular diameter measurements
• Zoomed views of the sinotubular junction, sinus of Valsalva, and ascending aorta, each with a diameter measurement
• RVOT grayscale and color, with PW Doppler peak velocity and VTI
• RV inflow grayscale and color; CW Doppler peak velocity if tricuspid regurgitation is present

Parasternal Short-Axis (PSAX)

• Great vessel level: grayscale of the pulmonary valve, PA, and branches; RVOT and main PA diameter measurements
• Aortic valve level: large-sector grayscale of the right atrium, tricuspid valve, RV inflow, RVOT, and aortic valve; zoomed aortic valve leaflets in grayscale and color; RVOT/PA Doppler (PW peak velocity and VTI; CW if pulmonic regurgitation is present); CW Doppler peak velocity of any tricuspid regurgitant jet
• Mitral valve level: grayscale and color of the leaflets
• Papillary muscle and apical levels: grayscale clips for regional wall motion assessment, plus a color sweep from the mitral valve through the papillary muscles to the apex

Apical

• A4C, A2C, and apical long-axis (three-chamber) views: full-sector and ventricular-focused grayscale clips
• Color Doppler across the aortic, mitral, and tricuspid valves in the appropriate views; CW Doppler through any regurgitant jet present (aortic, mitral, or tricuspid), measuring peak velocity and VTI
• PW Doppler of mitral inflow (E velocity, A velocity, deceleration time) and pulmonary venous inflow (S, D, and A waveforms)
• Tissue Doppler at the mitral annulus (lateral and medial e′, a′, s′) and tricuspid annulus (e′, a′, s′)
• LA and RA volumes, traced at end-systole with a long-axis length measurement
• Biplane (A4C and A2C) summation-of-disks LV volumes at end-diastole and end-systole
• Apical five-chamber view: PW Doppler of the LVOT and CW Doppler of the aortic valve, each with peak velocity and VTI
• RV-focused view: TAPSE by M-mode, RV basal and mid-cavity linear dimensions and length, RV area at end-diastole and end-systole
• Optional, where available: LV longitudinal strain and 3D LV volumetric acquisition

Subcostal

• Four-chamber grayscale and color
• Short-axis sweep, including the IVC in long axis: a clip demonstrating respiratory variation, plus a diameter measurement
• Hepatic vein grayscale, color, and PW Doppler showing the S, D, and A velocity waveforms

Suprasternal

• Aortic arch grayscale
• Narrow-sector color Doppler of the ascending aorta with PW peak velocity
• Narrow-sector color of the transverse arch and descending aorta, with PW (or CW, if the signal requires it) peak velocity

Doppler Acquisition Logic

Doppler mode selection follows directly from the flow being interrogated, not personal preference:

• Color Doppler is the first-pass screening tool — it shows where an abnormal flow is, which is what tells you where to aim spectral Doppler next, rather than being a stand-alone diagnostic measurement on its own.
• Pulsed-wave (PW) Doppler measures velocity and timing at a specific, known depth, and is used for low-velocity, laminar flows — mitral and tricuspid inflow, LVOT flow, pulmonary and hepatic venous flow. Its Nyquist limit means it aliases on high-velocity flows.
• Continuous-wave (CW) Doppler has no depth discrimination but measures velocity without an upper limit, making it the correct choice for high-velocity jets that would alias on PW — aortic stenosis, and any significant regurgitant jet (aortic, mitral, or tricuspid).

Instrumentation and Optimization

Gain, depth, and sector width should be optimized at every window rather than relying on transducer position alone — endocardial border definition depends on these settings as much as on where the transducer sits. Harmonic imaging is the default setting in most labs for its improved signal-to-noise ratio, particularly useful in technically difficult body habitus. Where image quality remains inadequate for LV endocardial definition across two or more contiguous segments, an ultrasound enhancing agent (UEA, sometimes still referred to by the older term “contrast”) should be used — see the discussion of agitated saline versus UEAs in the Echocardiography Basics tutorial for how these two very different agents are sometimes conflated.

Reporting Precision

Two conventions worth carrying from acquisition straight through into the report:

• Reporting precision has a ceiling — velocity, area, and most linear measurements should not be reported with more than one decimal place (for example, an aortic valve peak velocity of 4.2 m/s, not 4.21 m/s). Implying more precision than the measurement actually supports doesn’t add accuracy, just false confidence.
• Hemodynamic and volume measurements (calculated pressures, stroke volumes, regurgitant volumes, LVEF, LA volume) are reported as whole numbers, and where a value is more naturally expressed as a range (e.g., an estimated RA pressure of 0–5 mmHg), the average of that range is what gets reported as the single figure.

Common Pitfalls

• Foreshortening the apical views by not centering the true LV apex, which leads to underestimated LV volumes and an overestimated ejection fraction.
• Skipping the suprasternal window in patients where aortic arch pathology is a relevant consideration.
• Recording too few cardiac cycles, which limits the ability to average measurements or review the loop later.
• Under-optimizing gain, producing either dropout (too little gain) or blooming that obscures thin structures like valve leaflets (too much gain).
• Silently omitting a technically limited window rather than documenting it as such — the interpreting physician needs to know which findings carry full confidence and which don’t.

Documentation

A complete study should include representative loops from every window above, with Doppler interrogation of each valve, and clear labeling of any technically limited views so the interpreting physician understands the confidence level of any measurement made from them. See the Transthoracic Echocardiography: Reporting technique page for how these acquisitions translate into a structured report.