Splenic artery ultrasound is a Doppler-based imaging technique that measures blood flow through the artery supplying the spleen, providing information about vascular health in the spleen itself and, indirectly, about conditions elsewhere in the abdomen. Clinicians use it to screen for aneurysms, evaluate portal hypertension, monitor graft perfusion after liver transplantation, and track recovery following trauma. The exam is noninvasive and repeatable, which makes it especially useful for conditions that require serial follow-up over weeks or months.
What the Exam Actually Measures
During a splenic artery ultrasound, a sonographer places a transducer on the upper left abdomen and uses Doppler to record several flow parameters. The most commonly reported are peak systolic velocity (the fastest flow during a heartbeat), end-diastolic velocity (flow at the resting phase of the heartbeat), and calculated indices that reflect how much resistance the downstream vascular bed is offering. The two main indices are the resistive index and the pulsatility index. Higher values in either one signal that the vessels downstream from the measurement point are narrower or stiffer than normal, forcing the blood to encounter more resistance.
Early validation work compared Doppler-derived flow measurements against electromagnetic flowmeters implanted in animals and found a strong correlation, which gave clinicians confidence that abdominal Doppler could reliably estimate volume blood flow in the splenic artery and neighboring vessels from outside the body. That same work noted that the splenic artery normally shows lower vascular resistance than the superior mesenteric artery, reflecting the spleen’s continuously perfused, low-resistance circulation.1Wiley Online Library (Journal of Clinical Ultrasound). Quantitative measurement of abdominal arterial blood flow using image-directed Doppler ultrasonography: superior mesenteric, splenic, and common hepatic arterial blood flow in normal adults
Detecting Splenic Artery Aneurysms
Splenic artery aneurysms are the most common type of aneurysm affecting the abdominal visceral arteries. Many are discovered incidentally on imaging ordered for something else, but once identified they need monitoring because of the risk of rupture. Ultrasound is a natural first-line tool for surveillance since it avoids radiation and contrast dye, but standard gray-scale imaging has real blind spots here.
A study examining patients with known splenic artery aneurysms found that gray-scale ultrasound failed to detect the aneurysm in four of five cases. In three of those failures, a surrounding shunt between the splenic and renal veins obscured the aneurysm, and in the fourth, heavy calcification of the aneurysmal wall hid it from view. Adding color Doppler changed the picture dramatically: pulsed Doppler revealed a turbulent pulsatile flow pattern along the aneurysm wall, leading to a correct diagnosis in four of the five patients. Even in the one remaining case where color Doppler missed the aneurysm because of dense calcification, a related technique called power Doppler was able to visualize it.2PubMed. Splenic artery aneurysm: value of color Doppler and the limitation of gray-scale ultrasonography
The takeaway for patients undergoing surveillance is straightforward: if your sonographer is only using standard gray-scale imaging, a splenic artery aneurysm can easily be missed, especially when there is calcification or abnormal surrounding vasculature. Color and power Doppler are essential additions.
Evaluating Portal Hypertension and Liver Fibrosis
One of the most researched applications of splenic artery Doppler is assessing portal hypertension, the elevated pressure in the portal venous system that develops as chronic liver disease advances. The idea is appealing: rather than measuring portal pressure directly with invasive hepatic vein catheterization, clinicians could simply scan the splenic artery and use the resistance indices as a proxy. The evidence, though, is mixed.
An influential study compared splenic Doppler indices in cirrhotic patients against portal resistance measured by catheterization and found a strong correlation. Patients with large esophageal varices (a hallmark of severe portal hypertension) had higher resistive and pulsatility index values than those without varices, and the correlation between splenic impedance indices and catheter-measured portal resistance was tight.3PubMed. Splenic Doppler impedance indices: influence of different portal hemodynamic conditions However, later studies attempting to replicate this in clinical practice have been less encouraging. One found no significant difference in splenic indices between patients with and without esophageal varices,4Radiol Bras. Utilization of splenic impedance indices in the evaluation of portal hypertension and another similarly concluded that the splenic artery resistive and pulsatility indices were not helpful for predicting varices in patients with compensated cirrhosis.5PubMed. Is non-invasive diagnosis of esophageal varices in patients with compensated hepatic cirrhosis possible by duplex Doppler ultrasonography?
This inconsistency matters clinically. In advanced cirrhosis with clear hemodynamic changes, the splenic artery indices tend to track well with portal pressure. But in compensated cirrhosis, where identifying varices early would have the most practical value, the indices seem to lose their discriminating power. The test is probably most useful as one piece of a broader assessment rather than a standalone screening tool for varices.
A more promising application may be staging liver fibrosis itself. In patients with chronic hepatitis C, the splenic arterial pulsatility index performed well as a predictor of significant fibrosis and cirrhosis, with areas under the curve reaching about 0.89 for significant fibrosis and 0.92 for cirrhosis in a validation set. Researchers found that applying optimized cutoff values could correctly predict cirrhosis in roughly three-quarters of patients, potentially decreasing the need for liver biopsy.6PubMed. Noninvasive diagnosis of hepatic fibrosis in patients with chronic hepatitis C by splenic Doppler impedance index This is notable because liver biopsy, while still the gold standard for staging fibrosis, carries a small but real risk of complications, so a reliable noninvasive alternative is genuinely valuable.
Splenic Artery Steal Syndrome After Liver Transplantation
After a liver transplant, the newly grafted liver depends on adequate blood flow through the hepatic artery for survival. In some patients, the splenic artery “steals” blood away from the hepatic artery, diverting so much flow to the spleen that the liver graft becomes starved of arterial blood. This is called splenic artery steal syndrome, and it is a potentially devastating early complication that can lead to graft failure if not caught quickly.
Doppler ultrasound is the frontline detection method. In one reported case, Doppler performed in the first 48 hours after transplantation showed strong portal vein inflow but no detectable intrahepatic arterial perfusion, signaling that the hepatic artery was being outcompeted.7Annals of Hepato-Biliary-Pancreatic Surgery. Splenic artery steal syndrome after liver transplantation – prophylaxis or treatment?: A case report and literature review A study of 247 transplant recipients took the diagnostic workup further by using contrast-enhanced ultrasound in patients suspected of having the syndrome. In the eight confirmed cases, contrast-enhanced ultrasound showed a delayed and weak signal in the hepatic artery alongside a rapid, intense enhancement through the portal vein, a pattern that visually confirms the steal phenomenon. The researchers concluded that contrast-enhanced ultrasound was an effective way to identify the syndrome without resorting to angiography.8PubMed. Contrast-enhanced ultrasound diagnosis of splenic artery steal syndrome after orthotopic liver transplantation
For transplant recipients, serial Doppler exams in the first days after surgery are now routine at most centers. The ability to diagnose steal syndrome at the bedside with ultrasound, rather than waiting for angiography, buys critical time when graft survival hangs in the balance.
Contrast-Enhanced Ultrasound and the Spleen
Standard Doppler tells you about flow in larger vessels, but it cannot reliably characterize what is happening inside the splenic tissue itself. That is where contrast-enhanced ultrasound comes in. This technique involves injecting microbubble contrast into a vein and then watching the bubbles fill through the splenic artery and into the organ’s parenchyma in real time.
The normal spleen produces a distinctive filling pattern. Within the first 20 seconds after injection, contrast appears in the splenic artery and its branches. As the microbubbles spread into the organ, enhancement becomes uneven in a characteristic striped or “zebra” pattern during the arterial phase. Enhancement then becomes homogeneous after about 60 seconds and lasts for five to seven minutes.9Radiologia Brasileira. Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review Any deviation from this pattern, whether a persistent filling defect, early washout, or irregular enhancement, prompts further investigation.
For distinguishing benign from malignant splenic lesions, the results are impressive. One study found that contrast-enhanced ultrasound correctly differentiated benign and malignant splenic abnormalities in 49 of 50 cases, with a sensitivity of 100% and a specificity of 98%.10PubMed. Vascular pattern and diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in spleen alterations The technique has also proven useful in identifying complications that conventional ultrasound misses entirely, including infarcts, pseudoaneurysms, and active bleeding after abdominal trauma in children.11PubMed. Contrast-enhanced ultrasound of blunt abdominal trauma in children In vasculitis, where small-vessel inflammation can cause wedge-shaped splenic infarcts, contrast-enhanced ultrasound has been used to confirm infarction alongside other cross-sectional imaging.12BMC Nephrology. PR3 vasculitis presenting with symptomatic splenic and renal infarction: a case report and literature review
The broader appeal of contrast-enhanced ultrasound is practical: it is safe, inexpensive relative to CT or MRI, can be performed at the bedside, and provides valuable additional information about splenic abnormalities that often narrows the differential diagnosis to a short list.13PubMed Central. Contrast-enhanced ultrasound of the spleen
Monitoring After Splenic Artery Embolization
When the spleen is injured in trauma, surgeons increasingly prefer to save the organ rather than remove it, because the spleen plays a key role in immune function. One organ-preservation strategy is embolization: threading a catheter into the splenic artery and blocking it with coils or particles to stop bleeding while leaving collateral pathways to keep the spleen alive. After embolization, the question becomes whether the spleen’s blood supply is actually recovering over time, and Doppler ultrasound is the tool used to answer it.
A study of 17 trauma patients who underwent proximal splenic artery embolization measured intrasplenic Doppler at multiple time points: one day, one week, ten weeks, and ten months after the procedure. The researchers tracked velocities, resistance indices, and acceleration parameters and concluded that Doppler ultrasound was a useful tool for evaluating the improvement in intraparenchymal blood flow over time.14PubMed. Intraparenchymal Doppler ultrasound after proximal embolization of the splenic artery in trauma patients A separate follow-up study of 24 patients examined six to 63 months after embolization confirmed that intrasplenic blood flow was present and the splenic vein was open in every patient. That study also checked immune markers and found that splenic function was preserved.15Journal of Trauma and Acute Care Surgery. Proximal Splenic Artery Embolization for Blunt Splenic Injury: Clinical, Immunologic, and Ultrasound-Doppler Follow-Up
For patients who have undergone this procedure, serial Doppler exams provide reassurance that the spleen is receiving adequate blood supply without requiring repeat CT scans and their associated radiation.
Splenic Artery Ultrasound in Pregnancy
Splenic artery aneurysms are rare in the general population, but pregnancy is a well-recognized risk factor. The combination of increased blood volume, hormonal changes that affect vessel wall integrity, and elevated cardiac output can enlarge a pre-existing aneurysm or accelerate the formation of a new one. Rupture during pregnancy carries a high mortality rate for both the mother and the fetus.
Because of this risk, some authors have recommended routine screening of the splenic artery with ultrasound and Doppler in pregnant women who have predisposing factors, such as a history of aneurysm, portal hypertension, or connective tissue disorders.16Current Women s Health Reviews. Sudden Rupture of Splenic Artery Aneurysm in a Pregnant Woman Resulting in the Death of the Fetus: A Case Report and Review of Literature This is not yet standard practice in routine prenatal care, but awareness is growing, and women with known risk factors should discuss it with their obstetrician.
Sickle Cell Disease and Splenic Artery Flow
The spleen takes a heavy toll in sickle cell disease. Repeated episodes of sickling within the spleen’s tiny sinusoidal vessels lead to infarction, scarring, and eventually functional loss of the organ, a process known as autosplenectomy. Doppler ultrasound of the splenic artery can detect the vascular changes driving this process.
A study comparing splenic artery Doppler in patients with sickle cell disease against healthy controls found that all the major flow parameters were significantly higher in the sickle cell group. Peak systolic velocity, end-diastolic velocity, pulsatility index, resistive index, and the systolic-to-diastolic ratio were all elevated, reflecting increased downstream resistance in a spleen that has been progressively damaged by repeated vaso-occlusive episodes.17International Journal of Scientific and Research Publications. Doppler Sonographic evaluation of the Splenic artery among Sickle Cell Anemia Patients in a Nigerian Tertiary Health Institution These elevated indices may serve as early markers of splenic compromise before the organ has completely infarcted, potentially opening a window for closer clinical monitoring or early vaccination against encapsulated organisms that the spleen normally clears.
Pancreatic Cancer Staging
The splenic artery runs along the upper border of the pancreas, which means pancreatic tumors in the body or tail of the gland can invade it directly. Assessing whether a tumor has grown into or encased the splenic artery is a critical part of surgical planning, because major vascular involvement often determines whether a tumor is resectable.
Endoscopic ultrasound, which places the transducer inside the stomach or duodenum to get closer to the pancreas than external ultrasound can, is used to evaluate vascular invasion. In this context, sonographers specifically examine the splenic artery and splenic vein for tumors arising in the pancreatic body or tail.18Clin Endosc. Diagnostic Ability of Convex-Arrayed Endoscopic Ultrasonography for Major Vascular Invasion in Pancreatic Cancer Signs of invasion include loss of the normal fat plane between the vessel wall and tumor, irregularity of the vessel contour, and, in advanced cases, tumor growing directly into the arterial lumen. This evaluation complements CT and MRI and can sometimes detect subtle contact that cross-sectional imaging misses because of the higher spatial resolution achievable with an endoscopic probe placed centimeters from the vessel.
Wandering Spleen and Anatomical Variants
A wandering spleen is a rare condition in which the organ is not fixed in its normal position in the left upper abdomen but instead hangs on an elongated vascular pedicle and can migrate to the pelvis or even the right side of the abdomen. The danger is torsion: if the pedicle twists, the splenic artery and vein become kinked or occluded, cutting off blood supply and potentially leading to infarction.
Ultrasound is typically the first imaging study that identifies the problem, often when a patient presents with abdominal pain and a mass is found in an unexpected location. The exam can pinpoint the spleen’s abnormal position, measure its size, evaluate blood flow in the splenic artery and vein, and detect any thrombus that may have formed.19PubMed Central. Wandering spleen with torsion in pelvic: A case report and literature review If Doppler shows absent or severely reduced arterial flow, torsion is likely and surgical intervention becomes urgent. In cases where flow is preserved, the finding may still prompt elective splenopexy, a procedure to fix the spleen in place and prevent future torsion.
The splenic artery itself can show anatomical variation that matters during the exam. It is one of the most tortuous arteries in the body, and its course can vary considerably from person to person. In some individuals, it runs in a relatively straight line from the celiac trunk to the spleen; in others, it loops and coils dramatically, which can make it difficult to follow with ultrasound and can create aliasing artifacts on Doppler that mimic pathology. Experienced sonographers know to adjust their angle of insonation and use lower pulse repetition frequencies to account for this tortuosity, but it remains a common source of technically suboptimal exams. Body habitus also matters: overlying bowel gas and abdominal fat can obscure the splenic artery entirely, particularly in patients who are obese or unable to cooperate with positioning. When the standard transabdominal approach fails, the left lateral decubitus position with the transducer placed between the ribs over the spleen can sometimes salvage the exam by providing an acoustic window that bypasses the bowel gas.