When Is a Spleen Ultrasound Needed?

A spleen ultrasound is ordered when a doctor needs to check whether the spleen is enlarged or damaged, or to look at a spot found another way. It usually follows a clue pointing to the spleen, such as pain under the left ribs, blood counts that don’t add up, or a spleen the doctor thinks feels large. The scan uses sound waves rather than radiation, so it is safe, painless, and can be repeated as often as needed.

The Most Common Reasons Doctors Order One

Blood tests lead to a spleen scan because the spleen filters old blood cells out of circulation and stores some of them. When it gets large, it can trap too many cells and pull your counts down. The scan shows whether the spleen is a likely reason for the low numbers. If it isn’t, the doctor knows to look at the liver or bone marrow next.

Infections are a common cause of a swollen spleen. Mononucleosis is the classic one in teens and young adults, and a spleen enlarged by mono can make contact sports risky. Doctors may scan to see whether the spleen has shrunk back before letting someone return to sports. Other infections, including some in the blood, can also enlarge it. Many orders simply say “abdominal ultrasound,” which usually covers the liver, kidneys, and spleen together.

People with long-term liver disease or blood disorders such as sickle cell disease may have the spleen checked regularly. In sickle cell disease, routine scans of spleen size and texture help guide care.6PubMed Central. Sonographic evaluation of the spleen among sickle cell disease patients in a teaching hospital in Nigeria

Why a Physical Exam Is Often Not Enough

An enlarged spleen is often missed by a hands-on exam. In hospital patients, a physical exam alone found only about 4 in 10 of them.7PubMed Central. Point-of-care ultrasonography improves the diagnosis of splenomegaly in hospitalized patients Adding a quick bedside ultrasound found all of them in that group.8PubMed Central. Point-of-care ultrasonography improves the diagnosis of splenomegaly in hospitalized patients In another bedside comparison, the best hands-on method caught only about half of enlarged spleens, while ultrasound caught about 7 in 10.9PubMed. Performance of Point-of-Care Ultrasound Versus Traditional Physical Examination for the Bedside Evaluation of Splenomegaly

Part of the problem is location. The spleen sits high under the left ribs, behind the stomach, and a normal one usually can’t be felt at all. Belly fat or tight muscles make it harder still.

The usual hands-on method is to press under the left rib edge while you breathe in deeply, hoping the tip of the spleen bumps the fingers as it moves down. The other is percussion: tapping over the left lower chest and side to listen for a dull note instead of the hollow one made by air-filled lung and bowel. Both depend on the examiner’s skill and your build.

That’s why a doctor who can’t feel your spleen may still order a scan if your symptoms or blood tests suggest a problem. The reverse is more reliable: a spleen a doctor can clearly feel is very likely truly enlarged, and the scan then measures how much.10PubMed. Comparing Physical Examination With Sonographic Versions of the Same Examination Techniques for Splenomegaly Some doctors use a small handheld ultrasound for a quick look; if it seems off, a formal scan follows.

What Counts as a Normal or Enlarged Spleen

The average healthy adult spleen measures about 10.7 cm long, 7 cm wide, and 4 cm thick.11PubMed Central. Sonographic measurement of splenic size and its correlation with body parameters About 87% of healthy adults have a spleen 12 cm long or less.12PubMed Central. Sonographic measurement of splenic size and its correlation with body parameters Some imaging centers, though, describe 11 to 13 cm as a normal adult length.13United Diagnostic Services LLC. Spleen Ultrasound: Diagnostic Imaging of Spleen – UDS Because labs differ, a length around 12 to 13 cm may be read as borderline rather than clearly enlarged.

Body size and sex shift the picture. About 16% of healthy men have a spleen over 12 cm, compared with about 4% of women.14PubMed Central. Sonographic measurement of splenic size and its correlation with body parameters Taller people naturally have larger spleens, and some radiologists adjust the normal limit for height and sex.15PubMed. Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals In children, normal size depends on age, height, and weight, so charts by age are used.16PubMed. Normal Values of Spleen Length and Volume: An Ultrasonographic Study in Children

Your report usually lists spleen length in centimeters. Phrases like “mildly enlarged” or “upper limit of normal” signal a borderline result. It’s fair to ask whether the size was judged against your height and sex.

A normal scan shows a spleen with a smooth shape and even texture, sitting under the left ribs next to the left kidney. No spots, fluid, or uneven areas are seen.

A number slightly over the limit isn’t automatically a problem. Doctors read size alongside symptoms, blood tests, and the spleen’s texture, not as a stand-alone verdict. A borderline result often leads to nothing more than a note in the chart, or a repeat scan later to see whether the size has changed.

Liver Disease and Blood Disorders

Cirrhosis raises pressure in the vein that carries blood from the gut and spleen to the liver, which can swell the spleen. When scarring blocks the liver, blood backs up into the spleen, which is why a large spleen can be an early clue to serious liver scarring. Doctors may scan the spleen in someone with liver disease even when there is no belly pain at all.

A Doppler ultrasound, which shows blood flow, can tell an enlarged spleen from liver pressure apart from one caused by a blood disorder about 9 times in 10.17PubMed. Influence of the spleen on portal haemodynamics: a non-invasive study with Doppler ultrasound in chronic liver disease and haematological disorders It uses the same probe and adds only a few minutes. In cirrhosis, a bigger spleen tends to go with larger swollen veins in the gullet.18PubMed. Influence of the spleen on portal haemodynamics: a non-invasive study with Doppler ultrasound in chronic liver disease and haematological disorders

In sickle cell disease, the spleen can scar and shrink until it barely works, which happened in about a third of children and young adults in one large group.19PubMed. Expected Sonographic Appearance of the Spleen in Children and Young Adults With Sickle Cell Disease: An Update Ultrasound is a simple, safe way to track spleen size in this condition.20PubMed. Sonographic assessment of spleen size in Saudi patients with sickle cell disease Most young people with sickle cell and an enlarged spleen did not need it removed over about 6 years.21PubMed. Expected Sonographic Appearance of the Spleen in Children and Young Adults With Sickle Cell Disease: An Update Some infections become more dangerous without a working spleen, so people without spleen function usually need extra vaccines, and doctors may advise prompt care for any fever.

When a Spot Is Found on the Spleen

A lesion, meaning a spot or area that looks different, is often found on the spleen during scans done for other reasons.22PubMed. Algorithmic Approach to the Splenic Lesion Based on Radiologic-Pathologic Correlation Doctors judge these mainly by how they look, such as how many there are and whether they are fluid-filled or solid.23PubMed. Algorithmic Approach to the Splenic Lesion Based on Radiologic-Pathologic Correlation Radiologists sort chance spots of 1 cm or more into groups from clearly harmless to likely cancer, with follow-up based on that risk.24Roentgen Ray Review. Incidental Splenic Lesions: A Proposed Algorithm for Assessment and Management

Reports often use cautious phrases such as “likely benign” or “indeterminate,” and indeterminate simply means the picture alone could not settle the question. An indeterminate spot usually leads to a further look, such as contrast ultrasound or another scan, rather than straight to surgery.

A single fluid-filled spot, or one with tiny bright specks of calcium, is usually harmless.25PubMed Central. Ultrasonographic findings and differentiation of benign and malignant focal splenic lesions Many solid spots, a bullseye look, or masses elsewhere in the belly point more toward cancer, though appearance alone doesn’t settle it.26PubMed Central. Ultrasonographic findings and differentiation of benign and malignant focal splenic lesions

Contrast ultrasound, which uses an injected bubble liquid, raised correct calls of harmless versus cancer from about half to about 85%.27PubMed Central. Value of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Focal Splenic Lesions Contrast ultrasound can confidently identify cysts, blood-vessel growths, abscesses, and areas of dead tissue.28PubMed Central. Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review Extra bits of normal spleen tissue can look like tumors, and contrast ultrasound can prevent needless procedures.29PubMed Central. Splenoses and Other Ectopic and Heterotopic Splenic Tissue: The Use of Long-Lasting Enhancement in Contrast-Enhanced Ultrasound to Avoid Unnecessary Intervention

For the test, a small IV puts tiny gas bubbles into a vein. Over a minute or two, they show how blood moves through the spot. It uses no radiation and the bubbles are breathed out, but it is not available at every center.

After a spot is found, you can ask whether it looks clearly harmless or needs follow-up, when a repeat scan is planned and what kind, and whether your other health history changes the risk.

After an Injury to the Belly

After a car crash, fall, or sports hit, a fast emergency ultrasound checks for blood in the belly. It is mostly a search for free fluid, which in an injured person is assumed to be blood, around the spleen, liver, and in the pelvis. It answers a quick question about whether there is significant bleeding now, not a detailed question about the exact injury. An unstable person with fluid seen may go straight to surgery, while a stable person usually gets more imaging.

It detected about 7 in 10 spleen injuries overall, and about 86% of more serious ones.30PubMed. Ultrasound detection of blunt splenic injury It missed about 3 in 10 spleen injuries.31PubMed. Ultrasound detection of blunt splenic injury Small injuries without much bleeding are hard to see, and results depend on the operator and timing.32PubMed Central. Splenic Heterogeneity in Focused Assessment With Sonography for Trauma (FAST) Scan Led to the Diagnosis of Grade 2 Splenic Injury in a Pediatric Blunt Abdominal Trauma That is why a CT often follows.

After a hit to the left side, watch for pain under the left ribs that worsens, pain spreading to the left shoulder, or dizziness, fainting, or a fast heartbeat. These need emergency care even if a first scan was normal.

What the Scan Is Like and How to Prepare

Many centers ask you to skip food for several hours before a belly ultrasound to reduce gas. Gas in the bowel or a larger body size can block parts of the spleen from view.33Point-of-Care Ultrasound Certification Academy. Spleen Ultrasound – How to Measure Length of the Spleen and Assess for Splenomegaly with Ultrasound Fasting matters more for scans that include the liver and gallbladder, so you may be told to fast even though the spleen alone may not need it. Rules on food and water vary, and drinking water is often allowed, so confirm your center’s instructions.

On the day, you may change into a gown and lie on a padded table. Warm gel goes on your left side and belly. The scan is usually done lying on your back or right side, and the sonographer presses the probe between your ribs and asks you to breathe in and hold, which brings the spleen below the ribs. Lying on your right side also tilts the spleen toward the probe and moves bowel gas out of the way, which is why you may be asked to turn.

The sonographer takes measurements and saves pictures as the probe moves, so long quiet stretches are normal. They usually can’t give results during the scan, because a radiologist reviews the images afterward and writes the report, which typically reaches your doctor within a day or two. If Doppler is used, you may hear a whooshing sound, which is blood flow.

There is no radiation, so the scan is considered safe in pregnancy and for children. Pressure can feel uncomfortable if the area is tender, and you can ask for a pause if holding your breath is hard.

Other Tests That May Follow

In one comparison, ultrasound spotted spleen problems in almost all patients, more than CT did, especially lymphoma.34PubMed. Ultrasound or CT in splenic diseases For judging spleen cancers, PET, contrast ultrasound, and contrast CT perform similarly well, with MRI a little behind.35PubMed Central. Diagnostic performance of different imaging modalities for splenic malignancies: A comparative meta-analysis

CT may still come next because it shows the whole belly at once, including lymph nodes, and it is standard for staging cancers. It uses radiation and often an iodine dye. MRI uses magnets and radio waves instead, and it can show tissue detail that helps characterize a spot ultrasound could not settle. It takes longer and requires lying still inside a tube, which some people find hard. The team asks about implants such as pacemakers beforehand, since it is not safe for everyone.

When a spot needs a sample, a needle can be guided by ultrasound.36PubMed. Ultrasound-guided fine needle biopsy of the spleen: high clinical efficacy and low risk in a multicenter Italian study Serious complications happen in under 1% of these biopsies, with about 5% having any complication.37PubMed. Ultrasound-guided fine needle biopsy of the spleen: high clinical efficacy and low risk in a multicenter Italian study Bleeding is the main risk, occurring in about 4% with a larger needle in one study, with one person needing the spleen removed.38PubMed. Safety and diagnostic accuracy of percutaneous ultrasound-guided biopsy of the spleen: a multicenter study

To prepare, you may need to stop blood thinners as advised, and blood clotting tests are often checked first. You are watched for a few hours afterward for bleeding. Report new left-side or shoulder pain promptly.