Medicines and Health Technologies
The most common indication for an ultrasound exam of the spleen is to evaluate the overall size of the organ for splenomegaly. The spleen has multiple functions that include filtering of blood and fighting infections as part of the immune system.
Sonographic evaluation of the spleen includes assessment of size and the gray scale appearance of the parenchyma. Splenomegaly is a common clinical finding, although nonspecific, for many of the Neglected Tropical Diseases (NTD). Infections and abscess formation within the spleen can alter the gray scale appearance of the parenchyma.
Visceral Leishmaniasis is one of the NTD that is associated with splenomegaly; if left untreated 90% of patients die.
Ultrasound evaluation of the liver utilizes normal sonographic appearance of the parenchyma as the baseline to determine presence of disease.
Liver sonograms assess the overall size, border contour, gray scale appearance of the parenchyma including the bile ducts and blood vessels within the organ. Acute and chronic liver disease can be identified by changes to the sonographic appearance of these assessed areas of the liver.
Identification and monitoring of Hepatocellular diseases such as Hepatitis and Cirrhosis can be accomplished with sonography. It is estimated that in Latin America and the Caribbean 2.1 million people are Infected with Hepatitis B and 4.1 million are infected with Hepatitis C.
Chronic Hepatitis and Cirrhosis lead to a decrease in the overall size of the liver, the borders become lobulated rather than smooth, the hepaticytes becomes fibrotic which changes the gray scale appearance of the parenchyma, and the blood flow to and within the liver can reverse direction.
Additional ResourcesPAHO Web. Hepatitis
Ultrasound exam of the heart, also known as echocardiography, is performed to assess heart size, structural abnormalities or congenital anomalies. Sonography enables the physician to observe heart motion and blood flow in real time. Color and Spectral Doppler sonography are specific techniques that are used in echocardiography to evaluate the direction and velocity of blood flow throughout the heart chambers, valves, inflow and outflow vessels.
The parasitic disease Chagas is endemic in 21 countries in the Americas, with 28,000 new cases each year. Left untreated the disease can lead to irreversible damage to multiple organ systems, including the heart.
The effects of chronic Chagas disease on the heart include cardiomyopathy, abnormal heart rhythms, and aneurysms within the heart apex. Echocardiography could be utilized to identify and monitor progression of chronic Chagas disease.