Common Doppler artefacts and pitfalls

Artefacts are spurious signals that do not represent true signals or physical structures. It is important to differentiate artefacts from genuine signals in ultrasound studies as this may help avoid misinterpretations and measurement errors. The nature of many Doppler ultrasound artefacts is similar to 2D echocardiography artefacts, including inappropriate gain settings, mirror artefacts, and reverberation artefacts. However, as Doppler ultrasound is used to detect blood flow and myocardial velocity, it is susceptible to insonation (Doppler) angle error, aliasing, and other velocity-related artefacts. These will be presented in this chapter as two main types of artefacts: one that is related to spectral Doppler, and the other related to colour-flow Doppler ultrasound.

Ошибочная диагностика вегетаций на неизмененном аортальном клапане

В статье представлены два клинических случая ошибочной диагностики вегетаций на аортальном клапане у пациентов без клинической картины инфекционного эндокардита с неизмененным аортальным клапаном. Причиной ошибочной диагностики вегетаций явились артефакты ультразвукового изображения толщины луча. В статье приводится механизм формирования артефактов толщины луча на аортальном клапане. Обсуждаются способы дифференциации артефактов ультра звукового изображения толщины луча от истинных дополнительных эхогенных образований. Ключевые слова: эхокардиография, ультразвуковые артефакты, инфекционный эндокардит, аортальный клапан, echocardiography, ultrasound artefacts, infective endocarditis, aortic valve

Cardiac masses and potential sources of emboli

Cardiac masses are abnormal structures within or immediately adjacent to the heart. They have to be distinguished from variants of normal cardiac structures, postoperative changes, and ultrasound artefacts. These abnormal masses may be localized in the left or right heart cavities, with different clinical manifestations according to their localization. Among the abnormal cardiac masses (thrombus, vegetations, tumours), tumours are not discussed in this chapter. Echocardiography is the main but not the only imaging technique for the evaluation of cardiac masses, and is largely available. Hence, it is indicated in patients with a systemic embolic event, searching for a cardiac source embolism. When transthoracic echocardiography is negative, transoesophageal echocardiography is indicated, in cryptogenic ischaemic events (no cause found). Right heart masses are mainly responsible for pulmonary embolisms, but may be the cause of a systemic embolus, via the atrial septum. Right heart thrombi rarely form in situ, and are hence more often venous thrombi entrapped in the right heart on their way to the pulmonary arteries. Echocardiography is mandatory in the setting of pulmonary embolism.