Which frequency is commonly utilized when evaluating larger vessels in patients with obesity?

Using a frequency of 2 MHz for evaluating larger vessels in patients with obesity is appropriate due to the characteristics of ultrasound waves and the tissue composition of individuals with higher body mass.

Lower frequencies, such as 1 MHz, penetrate deeper tissues, which is useful in certain contexts but may not provide the resolution needed for clear imaging of larger vessels where detail is also important. In the context of obesity, where subcutaneous fat can impede high-frequency imaging, 2 MHz strikes a balance between adequate penetration and sufficient image resolution for assessing the structure and function of larger veins and arteries.

Frequencies higher than 2 MHz, such as 3 MHz and 4 MHz, have better resolution but are limited in penetration capability. This limitation can result in inadequate visualization of structures due to the increased attenuation caused by the layers of adipose tissue. Therefore, 2 MHz is commonly selected as the optimal frequency to ensure effective imaging in this patient population.