The writing group for the “Guidelines for the Cardiac Sonographer in the Performance of Contrast Echocardiography” recently published a focused update document in which we included the following statement: “the writing group does not consider patients with small degrees of right-to-left shunting through PFOs (those that result in a transient appearance of saline contrast in the left atrium or ventricle and do not fill the left atrial or LV cavity) at increased risk for UCA use.” Accordingly, we read with keen interest the retrospective cohort study performed by Kalra et al ., who found no adverse events after perflutren contrast administration in 418 patients with previously documented right-to-left shunts. Specifically, no neurologic events occurred in any of the patients. These findings provide direct evidence to support the safety of perflutren contrast in patients with small right-to-left shunts that would be secondary to a patent foramen ovale. We agree with Kalra et al . that the benefits of perflutren contrast in this setting far outweigh any risk and that there is no need to “screen” for small right-to-left shunts with saline contrast before perflutren use.