Medical ultrasound plays an integral role in providing patient care. This is in part because ultrasound can be used on every part of the body. Organs like the kidneys, liver, gallbladder, and the heart are all commonly assessed with ultrasound. It is even possible to scan the brain, the lungs, the arteries and veins.
HOW DOES IT WORK?
Ultrasound began with sonar. Sonar is what is used to see in the water. The sound waves are sent out and when it hits an object, the waves reflect back to a receiver and give a picture. The picture in sonar is a dot. This is how ultrasound began. Reading dots. Ultrasound now has morphed into the greatest diagnostic tool of our time that can see inside our body in real time. This means that as a heart beats, or as a baby moves in the womb, the ultrasound image updates and provides a representation of what is actually happening inside the body.
This allows doctors to non-invasively diagnose a patient without having to expose them to radiation or contrast dyes. Basically, ultrasound can see inside the body what a surgeon sees, but without a scalpel.
With medical ultrasound, organ structure and function can be accurately assessed, as well as the blood flow to the organ. Doppler technology, similar to the weather Doppler, is used to track the speed and direction of blood flow.
Cardiac ultrasound assesses the structure and function of the heart and the great vessels. This includes assessment of the heart muscle, valves, pericardium, ascending aorta, thoracic aorta, inferior vena cava, pulmonary veins, and pulmonary artery. Measurements are made to calculate pressures within the heart as it squeezes and relaxes, as well as how much blood is being pumped out of the heart.
Vascular ultrasound assesses the veins and arteries throughout the extremities (the arms and legs) as well as major vessels, like the carotid artery in the neck. It also includes assess all the vascular supply to and from organs and structures in the entire body. These tests allow for highly detailed measurement and assessment of blood flow. Although imaging the presence of plaque and blood clots is a major advantage of this test, vascular ultrasound also identifies any abnormal patterns of blood flow, hemodynamics and resistance, that can't be assess by any other diagnostic tool.
Abdominal ultrasound assesses the organs within the abdomen. This includes assessment of several organs and vessels like the abdominal aorta, liver, kidneys, pancreas, gallbladder, bile ducts, and the spleen. Abdominal ultrasound can identify any structural abnormalities, like aneurysms, as well as issues like cysts and mass. Blood flow through these organs is assessed with Doppler the same way blood flow is assessed in a vascular, or cardiac, ultrasound.
Breast ultrasound can be performed on women, or men, and can be used to help diagnose any abnormal lumps. Blood flow, or lack thereof, is assessed in a mass to help determine whether it is malignant or benign.
Transcranial ultrasound, also referred to as cranial ultrasound or head ultrasound, is a test that assesses the blood flow through the brain. This test can provide valuable information regarding structure and function of the infant brain, as well as in an adult who has suffered a stroke.
Pelvic ultrasound identifies any structural, functional, or blood flow abnormalities.
Transabdominal pelvic ultrasound used externally, placed on top of the pelvic bone using the urinary bladder as a window to get a broad picture of the pelvic organs and adjacent structures.
Transvaginal ultrasound is one of the few times when an ultrasound probe is used internally, instead of on the surface of the body, as the ultrasound probe is inserted into the vagina during the test. Transvaginal ultrasound allows for assessment of the entire female reproductive system. This includes the uterus, cervix, endometrium, ovaries, and fallopian tubes. It also allows for assessment of the bladder, although a bladder can be scanned externally as well.
A scrotal ultrasound allows for assessment of the testicles. This includes size, blood flow, and presence of any masses or lumps. During this exam, the kidneys and urinary bladder are also assessed.
Fetal ultrasound is used to monitor the growth and development of a fetus in the uterus. Fetal ultrasound can be done internally through a transvaginal ultrasound, or externally through an abdominal ultrasound. Fetal ultrasound allows for assessment of the development of all organs and structures in the growing fetus, as well as blood flow. Fetal ultrasounds happen at various times throughout the pregnancy and each have a different focus depending on when the exam is performed. For example, first trimester scans identify the presence and number of fetuses, while second and third trimester exams evaluate more specific features that are identifiable as the fetus grows.
Musculoskeletal ultrasound, also referred to as MSK, images the muscles, tendons, and ligaments in the body. It also is used to assess nerves. Bones are also being studies with ultrasound. This type of imaging is helpful in diagnosing muscle sprains and conditions like arthritis, but is advancing everyday to be able to assess more within this system.
Lung ultrasound is a newer type of medical ultrasound that is used to help detect respiratory problems like pneumonia and pulmonary fibrosis. It can also be used to help manage care for patients that are on mechanical ventilators in the hospital.
ADDITIONAL USES OF ULTRASOUND
In addition to being able to visualize a clot in a vein, or a mass in the pancreas, ultrasound is used to help guide several surgical procedures. This includes procedures like a liver or breast biopsy, or removal of abnormal fluid around the lungs, heart, or abdomen.
Ultrasound therapy - In addition to being used as a diagnostic and surgical tool, ultrasound is also used as a healing tool. Physical therapists and occupational therapists alike can use high frequency sound waves to help eliminate pain by reducing inflammation within muscles, tendons, and ligaments.
Point of care - While a formal, comprehensive ultrasound exam is typically performed by a trained sonographer, or ultrasound technologist, physicians have begun to implement ultrasound into their day-to-day routines, especially in hospital settings. Physicians can use ultrasound in emergent situations to make critical decisions quickly about how to care for a patient.
The benefits of ultrasound are undeniable. It is cost effective, non-invasive, and offers a wide array of usage. Most importantly, it can see the body in real time, in motion. Something no other modality can do. Additionally, the use of sonography protects patients from exposure to unnecessary radiation that is seen with other types of medical imaging. Ultrasound is used to diagnose pathology and monitor its progression. It is used in surgical procedures as well as to promote healing within the soft tissues. Although medical ultrasound has been used since the the 1950's, constant improvement in technology allows ultrasound to continue to advance and offer more solutions to patients as the demand for patient care increases.