Cardiology MCQ: Echo Basics

Adult transthoracic echocardiography uses frequencies in the range of:

A. 1-2 MHz

B. 2.5-5 MHz

C. 5.5-6.5 MHz

D. 7-10 MHz

Correct answer: B. 2.5-5 MHz

Higher frequency like 7-10 MHz can be used in pediatric imaging and in transesophageal echocardiography. Higher frequencies give better resolution, but penetration is poor. In an adult where the cardiac structures are at a higher distance for transthoracic echocardiography, lower frequency is preferred. In infants cardiac structures are nearer and smaller, making 7-10 MHz better for resolution and imaging is possible because of the shorter distance involved. Same applies to transesophageal echocardiography where heart is just in front of the esophagus. Modern broadband transducers allow us to change frequency with the same probe.

Reference: Braunwald’s Heart Disease, 12^th Edition, Page 197