Evaluation of saline versus gel as contact medium for ultrasonographic image quality.

Objectives: Evaluate the time taken to visualize the internal jugular vein and carotid arteries, and subjective image quality assessed on a 0-100 visual analogic scale, on an ultrasound model using either traditional ultrasound gel or normal saline.

Methods: Twenty-two anesthesiology residents and twenty anesthesiology faculty were blinded and randomized into four separate groups using gel and saline as a conduction medium, in different sequences.

Results: Subjective image quality was 12.2 ± 4.2 better with gel than with saline (P < 0.01). Image acquisition time did not differ significantly between the two mediums. There was no significant difference in subjective image quality or time to image acquisition between faculty and residents.

Conclusions: Internal jugular vein and carotid artery identification time using ultrasonography were similar between gel and saline as conduction mediums. The difference in subjective image quality did not appear clinically relevant. Better image quality resulted in less time taken to identify the structures, as expected. We conclude that saline may be an effective alternative medium to gel for vessel imaging and access guidance. Further study in a clinical setting is warranted.