Optison , Sonovue  and Luminity  have all been assessed for improvement of endocardial border delineation (EBD) during echocardiography in patients with sub-optimal image quality during unenhanced studies. These studies involved hundreds of patients and demonstrated that all three agents increased length of EBD (during end-systole and end-diastole), caused effective left ventricular opacification (LVO) and were able to ‘salvage’ an otherwise non-diagnostic study. When compared against a first-generation contrast agent, a markedly lengthier duration of action was noted for all second-generation agents.
As a consequence of this improved EBD and LVO, contrast imaging allows accurate calculation of ventricular volumes and ejection fraction and is superior to non-contrast enhanced harmonic imaging. Numerous studies have demonstrated this [4-7] and, in a multi-centre and multi-modality imaging study, LV volumes and LV EF as assessed by contrast echocardiography were as accurate as cardiac MRI and had the least inter-observer variability of all tests evaluated . No trial has ever shown contrast echocardiography to be inferior to another modality for the assessment of LV EF and LV volumes.
A recent study  also demonstrated the beneficial cost impact of contrast use during resting transthoracic echocardiography studies. 632 patients with sub-optimal image quality received contrast (Definity) and, amongst other factors, management decisions were compared before and after contrast administration. The percentage of uninterpretable studies was dramatically reduced (11.7% to 0.3%), further diagnostic tests were avoided in 32% of patients, drug management was altered in 10% and a cost/benefit analysis yielded a cost saving of $122 per patient .
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