Ultrasound Modes

B-mode (Bright)

This is the standard mode that produces a 2D grayscale image.

M-mode (Motion)

This mode displays motion over time along a selected line from the B-mode image. It is commonly used during lung assessments to evaluate heart valves, lung sliding, IVC, and assess for pneumothorax.

Colour Doppler

This mode visualizes blood flow in arteries and veins using colour patterns. It detects motion by measuring frequency shifts in returning sound waves as they bounce off moving blood. For best results, the probe should be angled less than 90° to the direction of flow (ideally lined up with it).
Red colour: Flow towards the ultrasound probe.
Blue colour: Flow away from the ultrasound probe.

Pulse Wave Doppler

This mode measures the velocity of blood flow at a specific point. The angle between the probe and the direction of blood flow (called the angle of insonation) should be as parallel as possible to get accurate readings. On the Doppler image, flow towards the probe appears above the baseline, and flow away appears below the baseline. Tip: use angle correction to align the Doppler cursor with the direction of flow.

Tissue Wave Doppler (TDI)

This is a type of pulse wave Doppler that measures the movement of tissue instead of blood flow. It's commonly used to assess heart muscle motion (e.g. in diastolic function assessment).

Continuous Wave Doppler

This mode measures high-velocity blood flow along the entire path of the ultrasound beam. It captures movement throughout the whole Doppler line, which means it’s less precise at pinpointing the exact location but it’s great for measuring very fast flow (i.e. aortic stenosis flow).