Abdominal Imaging
Live dataSplenic Index
Estimates splenic volume from three orthogonal dimensions and flags splenomegaly.
The splenic index is the product of the three maximal orthogonal splenic dimensions and serves as a simple surrogate for splenic volume. It, together with the craniocaudal length, is used to screen for splenomegaly on CT or ultrasound.
📐 Formula
Splenic index = length × width × thickness (cm³)
🎯 When to Use
- Objective assessment of spleen size on cross-sectional imaging.
- Serial monitoring in portal hypertension, haematological disease or infection.
- When a reproducible size metric is needed beyond a single length measurement.
⚙️ How It Works
- Measure the maximal craniocaudal length, width and thickness of the spleen on orthogonal planes.
- Multiply the three dimensions to obtain the splenic index in cm³.
- Compare against the normal range and check the craniocaudal length separately.
📊 Interpreting the Result
- Normal splenic index is approximately 120–480 cm³.
- Splenic index > 480 cm³ indicates splenomegaly.
- A craniocaudal length > 13 cm also defines splenomegaly.
⚠️ Limitations & Pitfalls
- The product of orthogonal diameters only approximates true volume; it assumes a regular shape.
- Normal ranges vary with body size, sex and height.
- Accessory spleens and lobulation can confound single-plane measurements.
📚 References
- Bezerra AS, D’Ippolito G, Faintuch S, et al. Determination of splenomegaly by CT: is there a place for a single measurement? AJR Am J Roentgenol. 2005;184(5):1510-1513.
- Prassopoulos P, Daskalogiannaki M, Raissaki M, et al. Determination of normal splenic volume on computed tomography in relation to age, gender and body habitus. Eur Radiol. 1997;7(2):246-248.
⚕️ For clinical decision support only. Always verify calculations and apply clinical judgment.