Infarct Volume ABC/2
Estimate ABC/2 lesion volume using caller-measured perpendicular diameters and fractional slice weights; irregular infarcts can violate the ellipsoidal approximation.
Description
ABC/2 approximates an ellipsoid-like lesion volume from two diameters and a weighted slice extent.
ABC/2 approximates an ellipsoid-like lesion volume from two diameters and a weighted slice extent. It is a geometric shortcut rather than voxel segmentation.
The tool returns weightedExtentCm (weighted extent cm); approximateVolumeMl (approximate volume ml). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Infarct Volume ABC/2
Use Infarct Volume ABC/2 when you already have longestDiameterCm, perpendicularDiameterCm, sliceThicknessCm, sliceWeights and want weightedExtentCm, approximateVolumeMl. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Infarct Volume ABC/2 and understand its results
- Enter longestDiameterCm, perpendicularDiameterCm, sliceThicknessCm, sliceWeights using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read weightedExtentCm, approximateVolumeMl. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| longestDiameterCm | Longest diameter cm | number | Required |
| perpendicularDiameterCm | Perpendicular diameter cm | number | Required |
| sliceThicknessCm | Slice thickness cm | number | Required |
| sliceWeights | Slice weights | list of number | Required |
Use positive dimensions with perpendicular diameter no larger than the longest and a nonempty slice-weight list in [0,1].
C = sliceThicknessCm×ΣsliceWeights; volumeMl = longestCm×perpendicularCm×C/2 The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"longestDiameterCm": 4,
"perpendicularDiameterCm": 3,
"sliceThicknessCm": 0.5,
"sliceWeights": [
1,
1,
0.5
]
},
"output": {
"weightedExtentCm": 1.25,
"approximateVolumeMl": 7.5
}
}Limitations and assumptions
Irregular lesion shapes can violate the approximation. Slice weights and measurements are supplied; the calculator does not identify an infarct.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Lesion Volume: Integrate lesion voxel fractions using anisotropic voxel dimensions; segmentation and partial-volume probabilities must be supplied. Cortical Surface Area: Sum triangle areas of a supplied cortical mesh with duplicate-face and index auditing; millimetre coordinates yield square millimetres.
Methodological background: The ABCs of measuring intracerebral hemorrhage volumes.1
References
-
The ABCs of measuring intracerebral hemorrhage volumes — Kothari et al.; Stroke
Similar or alternative tools
- Lesion Volume
Integrate lesion voxel fractions using anisotropic voxel dimensions; segmentation and partial-volume probabilities must be supplied.
- Cortical Surface Area
Sum triangle areas of a supplied cortical mesh with duplicate-face and index auditing; millimetre coordinates yield square millimetres.