Could you provide images illustrating the echocardiographic measurement techniques (LVOT diameter, vena contracta, PISA radius, continuous‑wave Doppler peak velocity, jet‑width ratio, descending aorta pulsed‑wave Doppler) used to assess aortic valve disease?

I cannot provide actual images of echocardiographic measurement techniques

Unfortunately, I do not have the capability to display, generate, or retrieve images. The evidence provided consists entirely of text-based guidelines and research articles without embedded figures or illustrations.

What the Guidelines Describe (Without Images)

The 2017 European/American echocardiography guidelines 1 provide detailed written descriptions of measurement techniques for aortic valve assessment:

LVOT Diameter Measurement

• Measured in parasternal long-axis view during mid-systole
• Taken from inner edge to inner edge (white-black interface) of the septal endocardium to the anterior mitral leaflet
• Parallel to the aortic valve plane
• Most experts measure at the annulus level for reproducibility due to clear anatomic landmarks 1
• The LVOT is often relatively rectangular within 1 cm of the aortic annulus, so measurements at different distances may yield similar results 1

LVOT Velocity (Pulsed-Wave Doppler)

• Recorded from apical approach in either the anteriorly angulated four-chamber view (five-chamber view) or apical long-axis view
• Sample volume positioned just proximal to the aortic valve
• Optimal positioning shows a smooth velocity curve with well-defined peak and narrow band of velocities throughout systole 1
• May need to move sample volume apically by 0.5–1.0 cm to obtain laminar flow without spectral dispersion 1

Aortic Valve Jet Velocity (Continuous-Wave Doppler)

• Must be obtained from multiple acoustic windows to avoid underestimation from beam misalignment 1
• A dedicated small dual-crystal CWD transducer is strongly recommended 1
• Peak velocity ≥4 m/s indicates severe aortic stenosis 1

Vena Contracta (for Aortic Regurgitation)

• Measured in parasternal long-axis or short-axis views
• Vena contracta >0.6 cm indicates severe AR 2
• Recent evidence shows VC is the strongest predictor of need for aortic valve surgery 3

Descending Aorta Flow Assessment

• Evaluated from suprasternal notch view 4, 5
• Holodiastolic flow reversal in proximal abdominal aorta indicates severe AR 2
• End-diastolic flow reversal (EFR) in upper descending aorta is a robust parameter for distinguishing moderate from severe AR 3

How to Access Actual Images

To obtain the actual measurement technique images you need:

1. Access the original guideline document directly: The 2017 EACVI/ASE recommendations 1 published in European Heart Journal contains Figure 5 showing LVOT diameter measurement technique with visual examples
2. Consult the 2025 BSE practical guideline 5 which provides step-by-step visual guidance
3. Review the 2026 JACC Case Reports practical protocol 4 which emphasizes optimal imaging techniques with illustrations

The text descriptions indicate these source documents contain the visual content you're seeking, but I cannot extract or display those images from the evidence provided.