Which transducer frequency should be used to evaluate the iliac vein in an individual with a Body Mass Index (BMI) of 32?

Using a transducer frequency of 2 MHz is appropriate for evaluating the iliac vein in a patient with a Body Mass Index (BMI) of 32. Generally, lower-frequency transducers, such as 2 MHz, penetrate deeper into the body tissues, making them ideal for imaging deeper structures like the iliac veins. Since higher BMI can increase the amount of subcutaneous fat, which in turn can attenuate ultrasonic signals, a frequency of 2 MHz allows for sufficient penetration while still providing adequate resolution to visualize the venous structures.

Higher frequencies (such as 3 MHz or 4 MHz) may provide better resolution in superficial structures but struggle with adequate depth penetration, consequently compromising the quality of the image for deeper vessels in patients with a higher BMI. A frequency of 1 MHz, while suitable for deeper imaging, may not offer the resolution required for a clear evaluation of venous anatomy in this specific context. Thus, the choice of 2 MHz strikes the appropriate balance between depth of penetration and image resolution needed for effective iliac vein assessment in this patient population.