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TOFD has a dead zone where it is not sensitive to defects, hence TOFD ought always to be supplemented by a conventional pulse-echo examination or phased array. The pulse echo probes are commonly mounted on the same buggy as the TOFD probes. Requires ultrasound technicians with advanced training.
Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, [9] is a congenital heart defect characterized by four specific cardiac defects. [4] Classically, the four defects are: [ 4 ] pulmonary stenosis , which is narrowing of the exit from the right ventricle;
Focused assessment with sonography in trauma (commonly abbreviated as FAST) is a rapid bedside ultrasound examination performed by surgeons, emergency physicians, and paramedics as a screening test for blood around the heart (pericardial effusion) or abdominal organs (hemoperitoneum) after trauma.
The echo pulses that are reflected are received by the same or by a different transducer and are converted into electrical signals which indicate the presence of the defect.” To characterize microstructural features in the early stages of fatigue or creep damage, more advanced nonlinear ultrasonic tests should be employed.
Time of flight (ToF) is the measurement of the time taken by an object, particle or wave (be it acoustic, electromagnetic, etc.) to travel a distance through a medium. This information can then be used to measure velocity or path length, or as a way to learn about the particle or medium's properties (such as composition or flow rate).
A diagnosis of TOF is usually made with echocardiography, which can even be done prenatally. Most patients with tetralogy of Fallot will have cardiac repair surgery in the first year of life, where the ventricular septal defect is closed with a patch, and the right ventricular outflow tract is enlarged.
A transthoracic echocardiogram (TTE) is the most common type of echocardiogram, which is a still or moving image of the internal parts of the heart using ultrasound. In this case, the probe (or ultrasonic transducer ) is placed on the chest or abdomen of the subject to get various views of the heart.
The reflected ultrasound is received by the probe, transformed into an electric impulse as voltage, and sent to the engine for signal processing and conversion to an image on the screen. The depth reached by the ultrasound beam is dependent on the frequency of the probe used. The higher the frequency, the lesser the depth reached. [9]