2.5: Ultrasonography
Ultrasonography is an imaging technique that uses high-frequency sound waves to visualize the body's internal structures. It is a non-invasive and safe procedure that does not involve the use of ionizing radiation, making it widely used in various medical fields. Ultrasonography is used to study heart function, blood flow in the neck or extremities, certain conditions such as gallbladder disease, and fetal growth and development.
During an ultrasonography procedure, a handheld device called a transducer is placed on the skin surface. The transducer emits high-frequency sound waves into the body, which then bounce back (echo) when they encounter different tissues and structures. The echoes are captured by the transducer and converted into real-time images on a computer monitor. These images provide valuable diagnostic information about the organs, tissues, and structures being examined.
Ultrasonography can be performed on various parts of the body, including the abdomen, pelvis, heart, blood vessels, thyroid gland, reproductive organs, and musculoskeletal system. It is commonly used for:
Diagnostic Purposes: Ultrasonography is used to assess and diagnose various medical conditions. It can help identify abnormalities, such as tumors, cysts, gallstones, kidney stones, and fluid collections. It is also used for evaluating the size, shape, and function of organs like the liver, kidneys, bladder, uterus, and prostate.
Obstetrics and Gynecology: Ultrasonography plays a crucial role in monitoring pregnancy and assessing fetal development. It is used to determine the gestational age and position of the fetus, detect multiple pregnancies and evaluate the health of the uterus and placenta. It is also used in gynecology to evaluate the ovaries and fallopian tubes and assess reproductive health.
Vascular Studies: Ultrasonography is employed for examining blood vessels and assessing blood flow. It can detect blockages, narrowing (stenosis), or abnormalities in the blood vessels, such as deep vein thrombosis or carotid artery disease. Doppler ultrasound, a specialized form of ultrasonography, is used to evaluate the direction and velocity of blood flow.
Musculoskeletal Imaging: Ultrasonography is utilized to evaluate the musculoskeletal system, including tendons, ligaments, muscles, joints, and soft tissues. It can help identify injuries, inflammation, and fluid accumulation (effusion) and guide needle placements for interventions, such as joint injections or aspirations.
The main disadvantage of ultrasonography is that the image quality is heavily operator-dependent and cannot penetrate bone and gas. Also, excess subcutaneous fat, seen in obese people, affects the image quality as it attenuates the echo, limiting clear visualization.
This content is derived from Openstax, Anatomy and Physiology, Section 1.7: Medical Imaging
