The expected benefit of USAT has been dependent on the device's ability to increase penetration of lytic into thrombus using high frequency, low power ultrasound, due to its reversible effects on fibrin dissociation. This benefit has been shown to result in faster thrombus clearance in selected vascular beds in some studies, such as the recently published DUET study comparing USAT and CDT in arterial occlusions. More rapid clearance of pulmonary thrombus by USAT compared to standard CDT may prove to be clinically and cost effective (e.g. via reduced length of ICU and hospital stay). Alternatively, if thrombus clearance is similar, the cost of USAT may exceed the cost of CDT (proprietary equipment and disposables), without offering any potential advantage. Evidence from the venous circulation, coming from the recent BERNUTIFUL trial demonstrated no difference in time to thrombus clearance in lower extremity deep venous thrombosis.