A spleen ultrasound is a non-invasive imaging technique that uses high-frequency sound waves to create detailed images of the spleen. This procedure allows medical professionals to visualize the spleen’s structure, assess its size, and identify potential abnormalities.
Why Spleen Measurement Matters
Measuring the spleen’s dimensions is important for identifying various health conditions. Changes in spleen size, such as enlargement or atrophy, can indicate underlying medical issues. An enlarged spleen, known as splenomegaly, is a common finding that prompts further investigation.
Medical professionals may request a spleen ultrasound if they suspect conditions like infections, including viral or parasitic infections, or blood disorders. Liver diseases, such as cirrhosis, can also lead to changes in spleen size. The scan helps in assessing trauma, detecting cysts, or identifying abnormal growths within the spleen.
The Spleen Ultrasound Procedure
Undergoing a spleen ultrasound is a straightforward process that involves minimal preparation. Patients are usually asked to lie on an examination table, often on their back or right side with their left arm raised to provide better access to the spleen. While fasting may be requested in some cases for general abdominal ultrasounds, it is not strictly required for a spleen-specific examination.
A clear gel is applied to the skin over the upper left abdomen, which helps the ultrasound transducer glide smoothly and ensures proper transmission of sound waves. A sonographer then moves a small, handheld transducer across the skin, capturing images of the spleen from various angles. The sound waves bounce off the spleen and are converted into real-time images on a monitor.
The procedure is generally painless and takes approximately 20 to 30 minutes to complete. Patients may be asked to change positions during the scan to facilitate better visualization of the organ. After the images are captured, the gel is wiped off, and individuals can resume their regular activities immediately.
How Spleen Measurements Are Taken
Accurate measurement of the spleen on ultrasound involves capturing specific views and dimensions. Sonographers use a low-frequency convex or curvilinear transducer for optimal imaging. Patient positioning is important, with the individual lying supine or in a right lateral decubitus position, sometimes with a deep breath held to bring the spleen into better view by causing it to descend.
The primary measurement taken is the longitudinal length, which is the greatest distance from the superior (top) pole to the inferior (bottom) pole of the spleen. This measurement is obtained in a mid-longitudinal view, ensuring both poles are visible. Calipers are placed at the uppermost and lowermost points of the spleen in this view to determine its length.
Additional measurements include the width and thickness. The width, or medio-lateral dimension, is measured from the medial to the lateral edge of the spleen. The thickness, or anteroposterior (AP) diameter, is measured from the anterior to the posterior margin, usually at the hilum (where blood vessels enter and exit). These measurements are taken on transverse views, or by rotating the transducer 90 degrees from the longitudinal view.
Interpreting Spleen Measurement Results
Once the spleen measurements are obtained, they are compared to established normal ranges to determine if the spleen is within expected size limits. For adults, a normal spleen measures between 11 to 13 centimeters in length, 5 to 7 centimeters in width, and 3 to 4 centimeters in thickness.
An enlarged spleen, or splenomegaly, is indicated when its longitudinal length exceeds 12 to 13 centimeters in adults. Spleen size can vary with age, height, and sex, especially in children, where specific age-related charts are used to define normal ranges.
Abnormal spleen measurements can point to various underlying health concerns. Splenomegaly can result from infections such as mononucleosis or malaria, blood disorders like leukemia or hemolytic anemia, and liver diseases including cirrhosis. A smaller than normal spleen can also indicate certain medical conditions, though this is less frequent.