"If the measurements are made in centimetres (cm), then the volume will be in cubic centimetres (cm3) or millilitres (mL) (numerically equivalent). The volume does tend to overestimate the true volume, with errors increasing in more irregularly-shaped and larger haemorrhages 7."
"ABC/2, also confusingly written as 1/2ABC in some literature, is a fast and simple method for estimating the volume of intracerebral haemorrhage (or any other ellipsoid lesion for that matter) which does not require volumetric 3D analysis or software."
"Intracerebral haemorrhage volume is an important predictor of morbidity and mortality (and thus trial eligibility) which is often under-reported 1. ABC/2 has been well-validated and correlates highly with volumes calculated by planimetric techniques, although does tend to overestimate 2,3,7."
"If π (Greek letter pi) is approximated to 3, then the formula can be simplified to ABC/2 (in truth, π is an irrational number, starting 3.141...)."
"In addition to the ABC/2 formula, there are other formulas which have been described and studied to estimate the volume of intracerebral haemorrhage 7:"
"ABCπ/6 (or π/6ABC): the precursor formula (Tada formula) to ABC/2 where π is estimated as 3 instead 7"
"ABCπ/6 (or π/6ABC): the precursor formula (Tada formula) to ABC/2 where π is estimated as 3 instead 7"
"ABC/3 (or 1/3ABC): was created to balance the over-estimation of ABC/2, but tends to under-estimate instead 7"
"ABC/3 (or 1/3ABC): was created to balance the over-estimation of ABC/2, but tends to under-estimate instead 7"
"2.5ABC/6 (or 2.5/6ABC): created to balance the over-estimation of ABC/2 and the under-estimation of ABC/3, has a greater accuracy than other formulas that use A, B, and C in one study 7"
"2.5ABC/6 (or 2.5/6ABC): created to balance the over-estimation of ABC/2 and the under-estimation of ABC/3, has a greater accuracy than other formulas that use A, B, and C in one study 7"
"SH/2 (or 1/2SH): derived from ABC/2 with the background theory that S will be slightly less than A x B, found to be the most accurate formula in one study (in comparison to other formulas including ABC/2) 7"
"SH/2 (or 1/2SH): derived from ABC/2 with the background theory that S will be slightly less than A x B, found to be the most accurate formula in one study (in comparison to other formulas including ABC/2) 7"
"SH/2 (or 1/2SH): derived from ABC/2 with the background theory that S will be slightly less than A x B, found to be the most accurate formula in one study (in comparison to other formulas including ABC/2) 7"
"SHπ/6 (or π/6SH): derived from ABCπ/6, and found to be the second-most accurate formula in one study after SH/2 7"
"SHπ/6 (or π/6SH): derived from ABCπ/6, and found to be the second-most accurate formula in one study after SH/2 7"
"SHπ/6 (or π/6SH): derived from ABCπ/6, and found to be the second-most accurate formula in one study after SH/2 7"
"There are some pitfalls with the ABC/2 method:"
"To overcome these pitfalls, there are alternative formulas available which may have greater accuracy, such as SH/2 (or 1/2SH) and 2.5ABC/6 (or 2.5/6ABC) 7."
"A = greatest haemorrhage diameter in the axial plane"
"B = haemorrhage diameter at 90º to A in the axial plane"
"If π (Greek letter pi) is approximated to 3, then the formula can be simplified to ABC/2 (in truth, π is an irrational number, starting 3.141...)."
Expected headings
"Formula"
"Mathematical basis"
"Alternatives"
"If the measurements are made in centimetres (cm), then the volume will be in cubic centimetres (cm3) or millilitres (mL) (numerically equivalent). The volume does tend to overestimate the true volume, with errors increasing in more irregularly-shaped and larger haemorrhages 7."
"4/3 π x (A/2) x (B/2) x (C/2)where A, B and C are the three diameters of the ellipsoid as defined above"
"There are some pitfalls with the ABC/2 method:"