What is a non-invasive ultrasound lower extremity?
Ultrasound is used primarily two ways:
- To generate heat for therapy of tendinopathies and myositis
- For non-invasive diagnostic imaging
The efficacy for musculoskeletal inflammation varies from patient to patient, but the benefits of ultrasound for diagnosing abnormal conditions of the cardiovascular system is well established.
Using the reflections of sound waves thousands of times faster (frequency) than those within the normal hearing range, an image can be rendered using the differences in these reflections. These differences are a result of the varying tissue densities of the structures that are struck and reflected. Ultrasound diagnostics have proved invaluable in pursuing conditions in the vascular system, from venous blood clots (thrombi) to arterial aneurysms and stenosis. The science of cardiac echocardiography has revolutionized the identification and management of cardiac disease.
Doppler technology takes advantage of differences rendered by motion. Doppler ultrasound, as opposed to regular ultrasound, is used to detect blood flow within arteries and veins and is useful in identifying problems of venous and arterial circulation.
The Lower Extremity
Due to gravity and the amount of blood that can pool within them, the legs present the biggest risk to the blood flow that is part of the circulation returning blood back to the heart. Compared to the arterial system, veins have a lower pressure for movement of the blood but are assisted by the presence of valves to prevent backflow and the compression/decompression of the leg muscles in ambulation and other movement that propagates blood upward. The heart is the primary pump, and the leg musculature serves as a secondary pump of the human body.
Deep Vein Thrombosis (DVT)
When this secondary pump fails, due to immobilization, coagulation abnormalities, or for unknown reasons, thrombi can form which pose a risk for separation from their thrombotic beds and migrating to the heart as emboli. The return of emboli to the right side of the heart propels them to the lungs along with the deoxygenated blood that carries them. This can result in varying degrees of obstruction in the ventilation process, from dyspnea to death.
Peripheral Arterial Disease
Atherosclerotic plaque formation and inflammatory conditions threaten the blood supply to the tissues distal from the narrowing or obstruction. This can cause ischemia, necrosis, ulceration, and possible sepsis.
Ultrasound of the Lower Extremity
Ultrasound is the preferred method of diagnosing thrombi when thrombophlebitis is suspected. It is also the first diagnostic choice for complications or identification of peripheral arterial disease. Other diagnostic modalities include MRI and CT, but ultrasound is the simplest, most cost-effective, and easiest to perform.