The spleen is an organ situated in the upper left quadrant of the abdomen, shielded by the lower ribcage. It is part of the lymphatic system, filtering blood by removing old red blood cells and storing white blood cells and platelets for immune response.
A spleen ultrasound is a non-invasive imaging test that uses high-frequency sound waves to create real-time pictures of this internal organ. A handheld transducer emits these waves, and the echoes are processed by a computer to form an image without using radiation.
Specific Reasons for the Examination
The most frequent indication for a spleen ultrasound is the suspicion or confirmation of splenomegaly, an abnormal enlargement of the organ. Systemic conditions like liver disease (e.g., cirrhosis) or blood disorders (e.g., leukemia or hemolytic anemia) can cause this. The scan allows doctors to monitor chronic diseases and assess treatment effectiveness by tracking changes in the spleen’s dimensions.
A spleen ultrasound is also standard following blunt trauma to the abdomen, such as a car accident or a fall. This quickly evaluates the spleen for signs of injury, including rupture, which is a medical emergency. The imaging identifies internal bleeding (hemorrhage) or a hematoma, a collection of blood within or beneath the splenic capsule.
The examination is frequently ordered to investigate unexplained discomfort or pain in the left upper quadrant of the abdomen. The ultrasound helps detect focal lesions, which are localized abnormalities within the splenic tissue. These may include cysts, abscesses, or solid masses that could represent benign or malignant tumors.
The scan also evaluates patients with known hematologic disorders where splenic function might be compromised. A doctor may order the test if a patient has abnormal laboratory results, such as low red or white blood cell counts, linked to splenic dysfunction. Visualizing the organ’s structure provides information that helps distinguish between potential underlying causes for a patient’s symptoms.
Preparation and What to Expect During the Scan
Preparation for a spleen ultrasound is generally straightforward, though fasting is sometimes required. Fasting, typically for six hours, minimizes gas in the bowel, which can interfere with sound waves and obscure the image. Patients should wear loose, comfortable clothing for easy access to the abdominal area.
During the procedure, the patient lies on an examination table, often on their back. To improve visualization, the technologist may ask the patient to lift their left arm above their head. A clear, water-based gel is applied to the skin over the left upper abdomen to ensure the transducer maintains contact and transmits sound waves effectively.
The technologist gently presses the handheld transducer against the skin and moves it across the area of interest. The patient may feel slight pressure as the device is manipulated to obtain images from different angles. To achieve clearer views, the patient may be instructed to take a deep breath and hold it briefly. The scanning process is quick, typically completed within 20 to 30 minutes, after which the gel is wiped off.
Understanding the Images and Diagnoses
The primary information provided by the ultrasound is a measurement of the spleen’s size, specifically its craniocaudal length (the distance from the top to the bottom pole). In adults, a maximum length measurement above 12 to 14 centimeters is commonly used as an indicator of splenomegaly. This longitudinal measurement is correlated with the overall splenic volume, quantifying the degree of enlargement.
Beyond size, the images reveal the internal structure, or echotexture, of the spleen’s tissue. A healthy spleen displays a uniform, fine, and homogeneous gray pattern on the screen. The radiologist looks for variations, such as bright spots that might indicate calcifications from prior infections or dark areas that could represent fluid-filled cysts or collections.
An extension of the standard examination is the use of Doppler ultrasound, a technique that assesses blood flow within the organ. This is useful for visualizing the splenic artery and vein, helping determine if there are signs of blood clots (thrombosis) or altered flow dynamics. Abnormal blood flow patterns can be an indirect sign of conditions like portal hypertension or splenic infarction (tissue death due to a lack of blood supply).
Ultimately, a specialized physician called a radiologist reviews the captured images and associated measurements. They interpret these findings, noting the size, shape, and structural irregularities, and compile a detailed report for the referring doctor. This report translates the visual data into a clinical context, which is then used by the patient’s physician to establish a diagnosis and formulate the treatment plan.