What Are Normal PSV and EDV Blood Flow Values?

Normal PSV and EDV values depend entirely on which artery is being measured, because every vascular bed in the body has its own characteristic flow profile. In the internal carotid artery, for example, peak systolic velocity typically falls between roughly 55 and 90 cm/s, while the common carotid artery usually stays under about 100 cm/s at peak systole. Renal arteries, intracranial arteries, and fetal vessels each have their own distinct ranges. Beyond the artery itself, your age, heart rate, blood pressure, and even the angle at which the ultrasound probe is positioned can shift the numbers meaningfully.

How PSV and EDV Work Together

When an ultrasound machine uses Doppler to measure blood flowing through an artery, two velocities matter most. PSV is the fastest speed blood reaches during heart contraction (systole). EDV is the speed at the end of heart relaxation (diastole), just before the next beat. Together, these two numbers tell the sonographer whether blood is flowing freely through an artery or meeting some kind of resistance downstream.

In arteries that feed organs needing constant blood supply, like the brain and kidneys, you expect relatively high EDV because the downstream tissue has low resistance and keeps accepting blood even between heartbeats. In arteries supplying resting muscles, EDV can be very low or even briefly reverse direction, because resting muscle tissue doesn’t demand much continuous flow. An in-vitro model study confirmed this relationship directly: as downstream resistance increased, EDV dropped while PSV actually rose, and the duration of systole shortened.¹ This is why you can’t interpret a PSV or EDV number without knowing which artery it came from and what that artery feeds.

Normal Values in the Carotid Arteries

The carotid arteries are the vessels most frequently assessed with Doppler ultrasound, usually to screen for narrowing that could raise stroke risk. The common carotid artery (CCA) sits in the neck and splits into the internal carotid (ICA), which feeds the brain, and the external carotid, which supplies the face and scalp. Because the brain demands constant perfusion, the ICA shows a relatively “low-resistance” waveform with prominent forward flow throughout diastole.

A large reference-interval study of over 1,100 people spanning ages 4 to 76 found that the left CCA had a mean PSV of about 114 cm/s, with most people falling between roughly 97 and 129 cm/s. Mean EDV in the same artery was about 29 cm/s. For the left ICA, mean PSV was about 91 cm/s and mean EDV about 35 cm/s. The right side ran slightly lower on average, with a right CCA PSV around 107 cm/s and right ICA PSV around 86 cm/s.² These side-to-side differences are well recognized and generally not a cause for concern.

A separate study of 100 adults found somewhat lower averages, with CCA PSV around 62–72 cm/s and ICA PSV around 57–58 cm/s. EDV in the CCA was about 19–21 cm/s and in the ICA about 16–21 cm/s. Women and men had broadly similar values, though the left side tended to read a few cm/s higher than the right for the CCA.³ The gap between these two studies illustrates something important: “normal” values can differ substantially depending on the population studied, the equipment, and the measurement technique. Radiologists interpreting your scan typically rely on their own laboratory’s reference ranges rather than a single universal number.

That said, there are some widely accepted upper boundaries. A European radiology educational resource puts normal ICA PSV at roughly 54 to 88 cm/s in the postbulbar segment, noting that values as high as 120 cm/s can occur in healthy people, though this is uncommon. CCA values above 100 cm/s at peak systole are considered unusual.⁴ One thing worth knowing: the carotid bulb, where the CCA widens before it branches, normally produces a distinctive swirling flow pattern that can look abnormal to an untrained eye. Velocities in the bulb tend to be lower than in the segment just past it, and brief flow reversal there is perfectly normal.

When Carotid Values Signal Stenosis

Clinicians care about PSV and EDV not because the resting numbers themselves are the diagnosis, but because rising velocities signal narrowing. When an artery narrows, blood speeds up through the pinch point, much like water through a garden hose when you partly cover the opening. The widely used consensus criteria for carotid stenosis set specific velocity thresholds: an ICA PSV of 125 to 230 cm/s suggests a 50–69% narrowing, while a PSV at or above 230 cm/s suggests 70–99% narrowing. Those higher-grade criteria showed a sensitivity of 99% and specificity of 86% in one validation study.⁵

Another study using high-resolution imaging found that combining a PSV of 155 cm/s or higher with an ICA-to-CCA ratio of 2 or more yielded a 97% positive predictive value for detecting at least 50% stenosis. For severe narrowing of 80% or more, they looked at EDV reaching 140 cm/s or above, along with PSV exceeding 370 cm/s.⁶ The practical takeaway: if your sonographer finds ICA PSV in the 60–90 cm/s range with a healthy EDV, there is almost certainly no significant narrowing. Once ICA PSV starts climbing past 125 cm/s, the conversation shifts to whether further imaging or intervention is needed.

Normal Values in the Renal Arteries

Renal artery Doppler is used to screen for renal artery stenosis or to monitor transplanted kidneys. Because the kidneys filter blood continuously, renal arteries show a low-resistance waveform with steady diastolic flow. A study of healthy adults in northwest Nigeria found that mean renal artery PSV was about 60–66 cm/s, with a slight side-to-side difference (left PSV was a bit higher in men, at roughly 66 cm/s, versus about 61 cm/s on the right). Mean EDV was in the low 20s cm/s on both sides for both sexes.⁷

In the setting of kidney transplants, the numbers shift. The transplanted kidney sits in the pelvis connected to the iliac artery, so the flow dynamics are different from a native renal artery. One study specifically looking at transplant patients found that roughly a quarter of patients without actual artery narrowing still had PSV above 250 cm/s at the surgical connection point in the first nine months after transplant. A similar proportion exceeded the ratio threshold commonly used to flag stenosis.⁸ This means that in transplant patients, a single elevated PSV reading should not be taken as proof of a problem. Clinicians need to consider the clinical context and often repeat the scan or use a different imaging technique to confirm.

Abdominal and Mesenteric Arteries

The celiac artery (CA) and superior mesenteric artery (SMA) supply the gut. In adults, average PSV is about 113 cm/s in the celiac artery and 145 cm/s in the SMA. Children have higher velocities in these same vessels, with celiac PSV averaging about 180 cm/s and SMA PSV about 175 cm/s.⁹ The higher velocities in children are related to their smaller vessel diameters and higher cardiac output relative to body size.

One practical detail about mesenteric arteries: the SMA flow pattern changes dramatically after eating. At rest, the SMA has a relatively high-resistance waveform. After a meal, downstream resistance drops as the intestines demand more blood for digestion, and both PSV and especially EDV increase. Clinicians are careful to scan these arteries after a period of fasting to get comparable baseline values.

Intracranial Arteries

Transcranial Doppler (TCD) measures blood flow velocity through the arteries at the base of the brain, most commonly the middle cerebral artery (MCA). Normal mean flow velocity in the MCA’s main segment averages about 58 cm/s, while the posterior cerebral artery averages about 39 cm/s and the basilar artery about 41 cm/s. These values show a clear decrease with age.¹⁰

When it comes to detecting MCA stenosis, velocity cutoffs matter. In patients with normal or only mildly narrowed arteries, mean systolic MCA velocity was about 122 cm/s. In moderate stenosis, it rose to about 156 cm/s, and in severe stenosis it reached roughly 199 cm/s.¹¹ TCD is frequently used in patients with sickle cell disease, subarachnoid hemorrhage, and stroke workup, where tracking changes over time is often more clinically useful than any single absolute number.

Fetal Doppler Values

In pregnancy, Doppler ultrasound measures blood flow in the umbilical artery and the fetal middle cerebral artery to assess whether the baby is getting enough oxygen and nutrition. The values change continuously with gestational age. In the fetal MCA, PSV grows from about 23 cm/s to 56 cm/s as pregnancy advances, with an overall average around 45 cm/s. The mean resistance index (RI) in the fetal MCA was about 0.80.¹² For the umbilical artery in the same study, EDV ranged from about 33 to 54 cm/s and RI decreased from about 0.72 to 0.57 as the pregnancy progressed, reflecting the placenta’s decreasing resistance over time.

These gestational-age-dependent changes are one reason obstetricians don’t use a single cutoff. Instead, measurements are plotted on reference charts that show the expected range for each week of pregnancy. PSV tends to rise as the fetus grows and its cardiac output increases, while resistance indices generally fall, especially in the umbilical artery, as the placental circulation matures and becomes more efficient at exchanging oxygen.¹³ If EDV in the umbilical artery disappears or reverses, that’s a red flag requiring urgent clinical attention, as it suggests dangerously high resistance in the placenta.

Why Age Changes Your Numbers

Age is one of the strongest predictors of what “normal” looks like on a Doppler ultrasound. The pattern is consistent across virtually every vascular bed studied: flow velocities decline with age. In the brain, this trend is dramatic. Blood flow velocities in the basal cerebral arteries are highest in children aged 5–10 and lowest in adults over 60, with a noticeable shift downward after age 40.¹⁴

The same pattern holds in smaller vessels. In the central retinal artery, both PSV and EDV decline with age while resistance indices climb.¹⁵ A study of ocular blood flow across all retrobulbar arteries found the same relationship: velocities dropped and resistance rose with advancing age.¹⁶ The mechanism involves progressive arterial stiffening and reduced compliance in both large and small vessels over time. This is why vascular laboratories typically stratify their reference ranges by age group rather than applying a single set of “normal” numbers to every adult who walks through the door.

Heart Rate, Blood Pressure, and Other Systemic Factors

Your cardiovascular state at the moment of scanning affects the readings. In a study of over 750 patients, lower heart rate was associated with higher pulsatility in the middle cerebral artery, and it was specifically linked to lower end-diastolic cerebral velocity.¹⁷ Higher diastolic blood pressure was associated with lower pulsatility, while higher systolic blood pressure pushed pulsatility up. In plain terms, the balance between your heart’s pumping strength and the pressure in your arteries during relaxation shapes what the EDV looks like on the scan.

Exercise has a measurable effect on peripheral vascular Doppler readings too. During and immediately after physical activity, arteries that normally show a high-resistance waveform in the legs can shift to a low-resistance pattern as working muscles demand more blood.¹⁸ In the eye, vigorous exercise briefly raised PSV in the ophthalmic artery, though smaller retinal arteries showed no significant velocity change.¹⁹ The clinical implication is straightforward: for consistent and comparable results, Doppler scans should be done with the patient at rest and in a relaxed state.

How Probe Angle Affects the Reading

One technical factor that trips up people comparing results from different scans is the Doppler angle, which is the angle between the ultrasound beam and the direction of blood flow. The machine uses this angle to calculate velocity, and even a small change in the angle setting can shift the numbers substantially. A study comparing measurements taken at 60 degrees versus 45 degrees in the carotid arteries found that PSV and EDV at 60 degrees were about 24% higher than at 45 degrees.²⁰ The good news: the diagnostic accuracy for detecting stenosis was similar at both angles, because the threshold values shift along with the measurements. But if you’re comparing your PSV from one appointment to your PSV from another, the angle used both times needs to match for the comparison to be meaningful.

In the kidneys, the angle issue is particularly tricky because the small intrarenal arteries run in many directions and are hard to align with the ultrasound beam. A study comparing angle-corrected versus non-angle-corrected measurements in intrarenal arteries found that PSV and EDV were significantly lower when no angle correction was applied. The resistance index, however, remained unchanged, which is one reason many kidney Doppler protocols rely more heavily on the resistance index than on absolute velocity numbers.²¹

Resistance Index and Pulsatility Index

You’ll often see RI and PI on your Doppler report alongside PSV and EDV. The resistance index is calculated from PSV and EDV, and it reflects how much the downstream tissue resists continuous blood flow. A high RI means there’s a big gap between the systolic peak and the diastolic trough, suggesting high downstream resistance. A low RI means diastolic flow stays relatively strong, indicating that the organ or tissue keeps accepting blood throughout the cardiac cycle.

Normal RI in the kidney is typically under about 0.70, though this varies with age and clinical context. In the internal carotid artery, a low RI is expected because the brain always needs blood. In the external carotid or a resting leg artery, higher RI values are normal because the tissue downstream isn’t demanding constant perfusion.

The pulsatility index captures a similar idea but uses the mean velocity rather than just EDV, making it somewhat more sensitive to the overall waveform shape. A reliability study found that both RI and PI showed better measurement consistency between different sonographers than either flow-mediated dilation or peak velocity measurements did, particularly after a physiological challenge like temporary blood flow restriction.²² This better reproducibility is part of why clinical protocols in many vascular labs report RI and PI alongside or even instead of raw velocity values, especially in organs where the angle of insonation is hard to standardize.

Why Your Report Might Not Match These Numbers

If you’ve had a Doppler ultrasound and are comparing your results to values published in research papers, expect some mismatches. Different ultrasound machines process signals slightly differently. Different labs use different Doppler angles, different patient positions, and different parts of the waveform to define “peak.” The reference ranges your lab uses were ideally calibrated using their own equipment and patient population, which is more relevant to your interpretation than a published study from a different country using different hardware.

Beyond equipment differences, your own physiology matters. If you were anxious during the scan, your heart rate and blood pressure were probably elevated, which can shift both PSV and EDV. If you had coffee beforehand, caffeine can alter vascular resistance in some beds. If you ate a large meal before an abdominal vascular study, the mesenteric arteries will show higher velocities than expected for a fasting state. Sonographers try to control for these variables, but they can’t eliminate all of them. What your clinician looks at is the overall pattern: the waveform shape, the velocity trend over time, the side-to-side comparison, and the resistance indices, all considered together. A single PSV number, on its own, rarely tells the whole story.