ultrasonographie

Ultrasonographie, also known as ultrasonography or sonography, is a medical imaging technique that uses high‑frequency sound waves to visualize internal structures. A transducer placed on the skin emits pulses and collects echoes reflected by tissues and organs. The returned signals are processed to produce real-time images, with brightness corresponding to tissue echogenicity. Modern systems combine B-mode imaging for structural visualization with Doppler modes to assess blood flow and velocity, including color and spectral Doppler.

Ultrasound examinations are used across many medical fields. In obstetrics, it is routinely employed for fetal assessment and monitoring. In emergency medicine and general imaging, it helps evaluate abdominal organs such as the liver, gallbladder, kidneys, and spleen, as well as the pelvis and uterus. Cardiology uses echocardiography to study heart structure and function. Additional applications include gynecology, vascular studies, thyroid and breast imaging, musculoskeletal assessment, and guidance for procedures such as needle placement or biopsies.

Procedure and safety: An external gel is applied to improve acoustic contact, and the transducer is moved to obtain views. Ultrasound is non-ionizing and generally considered safe, though energy exposure should be minimized and certain settings avoided in sensitive situations. Real-time imaging enables dynamic assessment, but results depend on operator skill and patient factors.

Limitations: Image quality can be limited by obesity, excessive bowel gas, or bone interfaces. Some tissues have similar echogenicity, making differentiation difficult. Deep structures may be challenging to visualize, and ultrasound may be complemented by other imaging modalities such as MRI or CT when needed.