Example Data Table
| Case | Shape | Sac size | Coil batches | Wire diameter | Expected use |
|---|---|---|---|---|---|
| Example A | Ellipsoid | 7.2 × 5.8 × 6.3 mm | 10 cm × 2, 8 cm × 1 | 0.254 mm | Routine density estimate |
| Example B | Sphere | 6.4 mm diameter | 6 cm × 3 | 0.203 mm | Round sac comparison |
| Example C | Manual | 140 mm³ volume | 12 cm × 2, 4 cm × 1 | 0.254 mm | Imaging software volume |
Formula Used
Ellipsoid aneurysm volume: V = π ÷ 6 × length × width × height.
Sphere volume: V = π ÷ 6 × diameter³.
Cylinder volume: V = π × radius² × height.
Coil volume: Vcoil = π × (wire diameter ÷ 2)² × coil length.
Packing density: Packing density = delivered coil volume ÷ aneurysm volume × 100.
Target extra length: Extra length = missing coil volume ÷ coil wire area.
How to Use This Calculator
Select the aneurysm shape first. Enter sac dimensions and choose the dimension unit. Use manual volume when an imaging workstation already provides sac volume. Enter neck width if you want an aspect ratio. Add the default coil wire diameter, simple coil length, and quantity. Use the batch box for several coils. Each line can use length, quantity, and optional wire diameter. Press calculate to view packing density, volume, target gap, and export buttons.
About the Aneurysm Packing Density Calculator
Aneurysm packing density describes how much coil material occupies an aneurysm sac. It is a volumetric ratio. The calculator uses the aneurysm shape, sac dimensions, coil length, and coil wire diameter to estimate that ratio. The result is useful for study, planning checks, and documentation. It does not replace professional judgment, imaging review, or device instructions.
Why Packing Density Matters
Packing density helps compare coil fill between cases. A higher value means more coil volume sits inside the sac. A lower value means the sac has more open space. Clinical teams may review this number with occlusion goals, neck geometry, rupture status, branch anatomy, and device limits. The number should be interpreted with the full case, not alone.
Geometry and Volume
The most common sac model is an ellipsoid. It uses length, width, and height. The formula is simple, but the measurement quality matters. Small changes in diameter can change volume quickly. A spherical model works for round sacs. A cylinder model can support teaching cases. Manual volume is available when a volume was measured from imaging software.
Coil Inputs
Coil volume is calculated from wire diameter and coil length. The batch box accepts several coil lengths and quantities. This makes the tool helpful when more than one coil is used. A loss percentage can be entered for practical planning. It reduces the delivered coil volume and gives a conservative estimate.
Target Planning
The target density field estimates the remaining coil length needed. This is only a planning aid. Actual treatment choices depend on anatomy, imaging, catheter position, coil behavior, and physician assessment. Use consistent units for every value. Export the result to CSV or PDF when you need a simple record.
Good Data Practice
Measure each dimension from the same imaging study when possible. Confirm whether values are inner sac diameters or outer estimates. Round only after the calculation, not before it. Keep coil diameter in millimeters, because manufacturer tables often list it that way. Save assumptions beside the final value. This helps another reviewer understand how the density was produced and why the result may differ from another tool. They also support safer team discussion during complex planning checks and audits later.
FAQs
What is aneurysm packing density?
It is the percentage of aneurysm sac volume occupied by coil material. It compares delivered coil volume with the estimated aneurysm volume.
Which aneurysm shape should I select?
Use ellipsoid for most sac estimates. Use sphere for round sacs. Use manual volume when imaging software already measured the sac volume.
What units should I use?
You may enter sac dimensions in millimeters, centimeters, or inches. The calculator converts them to millimeters before volume calculation.
How do coil batches work?
Enter one coil per line as length and quantity. Add an optional wire diameter after quantity when one coil uses a different diameter.
What is the delivery loss field?
It reduces usable coil volume by a percentage. This supports conservative planning when some coil length may not contribute to packing.
Is this tool for clinical decisions?
No. It is an educational and planning support tool. Treatment decisions require qualified clinical review and current device guidance.
Why does packing density change so much?
Volume depends strongly on dimensions. A small measurement change can create a larger volume change, especially in irregular sacs.
What does additional length mean?
It estimates coil length still needed to reach the target density. It assumes the default wire diameter and perfect added delivery.