In physics, the Nyquist limit is a fundamental concept in digital signal processing, particularly crucial in medical ultrasound. It states that to accurately reconstruct a signal, the sampling rate must be at least twice the highest frequency component of the original signal. Exceeding this limit leads to aliasing, where high-frequency information is misrepresented as lower frequencies.
In ultrasound, understanding the Nyquist limit is vital for preventing aliasing in Doppler imaging, which can misrepresent blood flow velocities. Sonographers must adjust the pulse repetition frequency (PRF) to ensure the sampling rate is sufficient for the velocities being measured, thereby optimizing diagnostic accuracy and avoiding misleading flow patterns in medical ultrasound scans.
