addition of an ultrasound contrast medium, or imaging agent, to traditional ultrasonography. The ultrasound contrast is made up of tiny microbubbles filled with a gas core and protein shell. This allows the microbubbles to circulate through the cardiovascular system and return the ultrasound waves, creating a highly reflective image. There are multiple applications in which contrast-enhanced ultrasound can be useful. The most commonly used application is in the enhancement of LV endocardial borders for assessment of global and regional systolic function. Contrast may also be used to enhance visualization of wall thickening during stress echocardiography, for the assessment of LV thrombus, or for the assessment of other masses in the heart. Contrast echocardiography has also been used to assess blood perfusion throughout myocardium in the case of coronary artery disease. Accreditation Echocardiography can at many times be subjective, meaning that the person reading the echo may have personal input that affects the interpretation of the findings, leading to so-called "inter-observer variability", where different echocardiographers might produce different reports when examining the same images. It necessitated the development of accreditation programs around the world. The aim of such programs is to standardize the practice of echocardiography and to ensure that practitioners have the proper training prior to practicing echocardiography which will eventually limit inter-observer variability. Europe At the European level individual and laboratory accreditation is provided by the European Association of Echocardiography (EAE). There are three subspecialties for individual accreditation: Adult Transthoracic Echocardiography (TTE), Adult Transesophageal Echocardiography (TEE) and Congenital Heart Disease Echocardiography (CHD). UK In the UK, accreditation is regulated by the British Society of Echocardiography. Accredited radiographers, sonographers, or other professionals are required to pass a mandatory exam. United States The "Intersocietal Accreditation Commission for Echocardiography” (IAC) sets standards for echo labs across the US. Cardiologists and sonographers who wish to have their laboratory accredited by IAC must comply with these standards. The purpose of accreditation is to maintain quality and consistency across echocardiography labs in the United States. Accreditation is offered in adult and pediatric transthoracic and transesophageal echocardiography, as well as adult stress and fetal echo. Accreditation is a two-part process. Each facility will conduct a detailed self-evaluation, paying close attention to the IAC Standards and Guidelines. The facility will then complete the application and submit actual case studies to the board of directors for review. Once all requirements have been met, the lab will receive certification.