Estimating the volume of intracranial hematoma on CT

The commonly used formula for estimating the volume of intracranial bleed on CT is


ABC/2 
where

A is the maximal diameter of the hematoma by CT
B is the diameter 90° to A, and
C is the approximate number of CT slices with hemorrhage multiplied by the slice thickness

For a number of years, I could not really grasp why the formula is as such. I thought that the formula is derived from the

Grey-Turner Sign

Grey-Turner’s sign simply refers to the bluish discoloration of the flanks. The interesting thing about this sign is that whenever this sign is found, medical students are alerted to the fact that there is a possible underlying retroperitoneal bleeding going on.  Obviously, this sign could also indicate a possible intraperitoneal bleed besides the possibility of retroperitoneal bleed. The

Can We Avoid Head CT scan in Some Pediatric Patients With Head Trauma?

In a multicenter trial published in Lancet recently, Kuppermann N et al. enrolled 42,412 children (age, ≤18 years) with mild head trauma (defined as Glasgow Coma Scale score >13) to derive and validate decision rules for two separate age groups:- those below 2 years and- those aged 2 years and above.In that paper, the authors highlighted the need to identify pediatric patients with very low risk