FibroScan Results Explained: What Your kPa, CAP, IQR and UAP Numbers Mean
If you've just received your FibroScan results and the numbers don't make sense, you're in the right place. This guide explains what each measurement means, what's normal, and what to do next.
Your FibroScan report contains up to three numbers: a kPa value (liver stiffness), a CAP or dB/m value (liver fat), and sometimes an IQR ratio (result reliability). Here's what each one tells your doctor — and you.
The kPa Result — Liver Stiffness (Fibrosis)
The kPa (kilopascal) number measures how stiff your liver is. Stiffness is caused by scar tissue (fibrosis). A healthy liver is flexible and soft. A scarred liver becomes harder and less elastic.
| kPa Result | Fibrosis Stage | What It Means | What Typically Happens Next |
|---|---|---|---|
| < 7.0 kPa | F0–F1 | Normal to minimal fibrosis | Annual FIB-4 blood test |
| 7.0–9.5 kPa | F1–F2 | Mild to moderate fibrosis | Clinical review; repeat in 12–24 months |
| 9.5–12.5 kPa | F2–F3 | Moderate to significant fibrosis | Specialist referral likely |
| 12.5–15 kPa | F3 | Advanced fibrosis | Specialist referral |
| > 15 kPa | F3–F4 / Cirrhosis | Possible cirrhosis | Urgent specialist referral |
The rule of 5 (quick reference)
Clinicians often use a shorthand: < 5 kPa normal; 5–10 kPa mild to moderate fibrosis; 10–15 kPa advanced fibrosis; > 15 kPa cirrhosis risk. This is a rough guide — your doctor will use disease-specific thresholds.
Important: These thresholds apply to MAFLD. They differ for hepatitis B (treat above 7 kPa per WHO 2024 guidelines) and hepatitis C. Always interpret with your doctor.
The IQR Result — Reliability Score
IQR stands for Interquartile Range. During your scan, the device takes 10 individual measurements and averages them. The IQR tells you how consistent those 10 measurements were. A low IQR means they agreed closely — a reliable result. A high IQR means they varied widely — the result may not be accurate.
Your report may show the IQR/M ratio (IQR divided by the median stiffness). This is the number to check for reliability.
IQR/M ratio — what the number on your report means
| IQR/M Ratio | What It Means | What To Do |
|---|---|---|
| ≤ 10% | Excellent reliability | High confidence in result |
| 11–20% | Good reliability | Reliable result |
| 21–30% | Acceptable reliability | Result is valid |
| > 30% | Unreliable | Discuss repeat scan with your doctor |
If your report shows IQR/M above 30%, the measurements were too inconsistent to be confident in the result. This is common in patients with higher BMI, if you had eaten recently, or if there was movement during the scan. Ask your doctor whether the scan should be repeated.
IQR 7 in FibroScan
IQR of 7% = excellent reliability, high confidence
IQR 12 in FibroScan
IQR of 12% = good reliability, reliable result
IQR 15 in FibroScan
IQR of 15% = good reliability
IQR 17 in FibroScan
IQR of 17% = acceptable — within the 30% threshold
If your IQR was above 30%, your doctor may suggest repeating the scan with a guided elastography system, which uses real-time ultrasound imaging to place the probe precisely. Guided systems achieve lower IQR values because the operator can see exactly where the measurement is being taken. FibroScan vs other scan types →
The CAP Score — Liver Fat (Steatosis)
CAP stands for Controlled Attenuation Parameter. It measures how much fat is in your liver, on a scale from roughly 100 to 400 dB/m. More fat in the liver slows down sound waves — a higher CAP number means more fat detected.
| CAP Score | Steatosis Grade | Fat in Liver Cells | Clinical Meaning |
|---|---|---|---|
| < 238 dB/m | S0 — Normal | < 5% | No significant fat accumulation |
| 238–259 dB/m | S1 — Mild | 5–33% | Mild steatosis — often reversible with lifestyle change |
| 260–292 dB/m | S2 — Moderate | 34–66% | Moderate steatosis — warrants clinical assessment and management |
| > 292 dB/m | S3 — Severe | > 67% | Significant fatty liver disease — active management required |
CAP score 300
S2–S3 range (moderate to severe). Significant fatty liver. Not liver failure — many people with S3 reduce their liver fat through weight loss and diabetes management.
CAP score 292
The threshold between S2 and S3. Right on the boundary. Your doctor will interpret in context.
CAP score 350
S3 — severe steatosis. Significant fatty liver. Warrants active clinical management.
CAP score 400
S3 — severe. The scale typically tops out around 400 dB/m.
UAP — If You Were Scanned on a Guided Elastography System
If your report shows UAP (Ultrasound Attenuation Parameter) in dB/m rather than CAP, you were likely scanned on a guided 2D shear wave elastography system rather than a standard FibroScan. UAP and CAP both measure liver fat content, but they use different measurement methods.
The UAP number on your report is NOT directly comparable to a CAP number. If you had a previous FibroScan and are comparing results, compare the steatosis grade (S0, S1, S2, S3) — not the raw dB/m figure. The grade is equivalent; the number is not.
| UAP Score | Grade | Meaning |
|---|---|---|
| < 0.6 dB/m/MHz | S0 | Normal liver fat |
| 0.6–0.8 dB/m/MHz | S1 | Mild steatosis |
| 0.8–1.0 dB/m/MHz | S2 | Moderate steatosis |
| > 1.0 dB/m/MHz | S3 | Severe steatosis |
UAP thresholds vary by the specific device protocol used. Ask your clinic for the reference range they use.
What to Do Next
Your FibroScan result is one piece of information. Your doctor will interpret it alongside your blood tests (FIB-4, ALT, AST, GGT), your medical history, and your risk factors.
- kPa above 8 kPa → clinical review recommended
- CAP or UAP above S2 grade → discuss with your doctor
- IQR/M above 30% → ask about repeating the scan
If your scan was unreliable and your doctor recommends repeating it, ask about guided elastography — it uses real-time ultrasound imaging to improve accuracy, particularly for patients with higher BMI.
Not sure what your result means?
Find an elastography clinic near you and ask your GP to review your FibroScan report together.
FibroScan results — common questions
What is IQR in a FibroScan result?
IQR stands for Interquartile Range. It measures how consistent your 10 FibroScan measurements were. An IQR/M ratio of 30% or below is considered reliable. Above 30% means the result may not be accurate.
What is the normal IQR range for FibroScan?
An IQR/M ratio of ≤30% is considered reliable. Below 10% is excellent. Above 30% is unreliable and usually warrants repeating the scan.
What does an IQR of 15 mean on FibroScan?
An IQR of 15% is a good result — well within the reliable range of ≤30%. Your kPa measurement can be interpreted with confidence.
What is the normal range of CAP in FibroScan?
A CAP score below 238 dB/m is considered normal (S0 grade, less than 5% liver fat). 238–259 is mild steatosis (S1), 260–292 is moderate (S2), and above 292 is severe steatosis (S3).
What does a FibroScan CAP score of 300 mean?
A CAP of 300 dB/m puts you in the S2–S3 range, indicating moderate to severe hepatic steatosis — significant fatty liver disease. This warrants clinical management but does not mean liver failure. Many people reduce their CAP score through lifestyle changes.
What is a normal kPa on FibroScan?
For MAFLD, a liver stiffness below 7 kPa is generally normal. 7–9.5 kPa is mild to moderate fibrosis, and above 12.5 kPa suggests significant fibrosis or cirrhosis. Thresholds vary by liver condition — always interpret with your doctor.
Is FibroScan covered by Medicare in Australia?
No. MSAC rejected FibroScan (VCTE) for Medicare funding in early 2025 (Application 1797). Scans are charged privately: typically $150–$330 AUD out of pocket. Some rebate may be available when elastography is performed as part of a standard abdominal ultrasound in a radiology setting.
What is UAP in a liver scan report?
UAP (Ultrasound Attenuation Parameter) is a liver fat measurement used by some guided 2D shear wave elastography systems. It measures the same thing as CAP on FibroScan (liver fat content, graded S0–S3) but uses a different measurement method. The raw dB/m numbers are not directly comparable between devices — compare the grade, not the number.
What does FibroScan E(kPa) median mean?
E(kPa) median is the median of your 10 liver stiffness measurements, expressed in kilopascals (kPa). This is the primary result on your report. Higher kPa = stiffer liver = more fibrosis. The median (middle value) is used rather than the average to reduce the impact of outlier measurements.
What is a bad FibroScan result?
A result is concerning if the kPa is above 9.5 (moderate fibrosis), the CAP is above 292 (severe steatosis), or the IQR/M ratio is above 30% (unreliable measurement). A high result is not a diagnosis — it is a finding that needs clinical follow-up, not panic.
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Medical disclaimer: All content on this page is educational and is not intended as medical advice. Diagnosis and treatment decisions must be made by a qualified healthcare professional. If you have concerns about your liver health, speak with your GP.