Mathematical model in post-mortem estimation of brain edema using morphometric parameters

Abstract

Current autopsy principles for evaluating the existence of brain edema are based on a macroscopic subjective assessment performed by pathologists. The gold standard is a time-consuming histological verification of the presence of the edema. By measuring the diameters of the cranial cavity, as individually determined morphometric parameters, a mathematical model for rapid evaluation of brain edema was created, based on the brain weight measured during the autopsy. A cohort study was performed on 110 subjects, divided into two groups according to the histological presence or absence of (the – deleted from the text) brain edema. In all subjects, the following measures were determined: the volume and the diameters of the cranial cavity (longitudinal and transverse distance and height), the brain volume, and the brain weight. The complex mathematical algorithm revealed a formula for the coefficient ε, which is useful to conclude whether a brain edema is present or not. The average density of non-edematous brain is 0.967 g/ml, while the average density of edematous brain is 1.148 g/ml. The resulting formula for the coefficient ε is (5.79 × longitudinal distance × transverse distance) / brain weight. Coefficient ε can be calculated using measurements of the diameters of the cranial cavity and the brain weight, performed during the autopsy. If the resulting ε is less than 0.9484, it could be stated that there is cerebral edema with a reliability of 98.5%. The method discussed in this paper aims to eliminate the burden of relying on subjective assessments when determining the presence of a brain edema.

A Suggested Formula for Postmortem Estimation of Brain Edema Using Morphometric Parameters in Egyptian Population

“…To exclude the cranial height, as it is a nonstandard measure during autopsy, we multiply the resultant factor (0.429) by the mean of the height (12.59 cm), so the new factor was 0.429 × 12.59 = 5.4. This accords with the results of Radojevic et al, 4 who found the mean height (12.19 cm) and the ε ( h ) (5.79). The final equation was as follows:…”

“…The diameters of the cerebral cavity were measured using a slide caliper in the central sagittal area, the transversal plane’s widest level, and the frontal plane for the depth. To determine the depth, a hole was drilled at the top of the skull, the obtaining portion of a slide caliper was pulled through it, and the length to the middle of the clivus of the occipital bone was measured 4 …”

Postmortem evaluation of brain edema: An attempt with measurements of water content and brain-weight-to-inner-skull-circumference ratio

“…They also found no significant correlation between increased brain weight and perivascular distension observed in histology slides (7). Radojevic et al very recently argued that not only the weight of the brain but also its volume plus that of the cranial cavity must be taken into account when evaluating potential brain edema (8). Berger et al had some success in diagnosing edema when using postmortem CT images to assess narrowing of the temporal horns and herniation of the cerebellar tonsils (9).…”

“…Radojevic et al introduced a coefficient calculated as ε=5.79(longitudinal distance in the skull)(transverse distance in the skull)/brain weight(8). The constant 5.79 takes into account both the height of the skull as well as the density of brain tissue as determined based on cases included in their study.…”

Postmortem water contents of major organs with regard to the cause of death

“…Furthermore, other than organ weight, no quantitative indicators are available to connect the effects of variation in the TWC and the cause of death. 12 In the clinical medicine field, hematocrit is used to measure the ratio of erythrocyte flow to total blood flow. When the organs absorb water from the blood, hematocrit is expected to increase 13 ; however, to our knowledge, no previous reports have evaluated this relationship using an autopsy sample.…”