The quantification of liver anatomical changes and assessment of occupant liver injury patterns.

Liver injuries can be significant in vehicle crashes. In this study, the liver anatomy was quantified in both adult and pediatric populations as a function of gender and age. Five anatomical liver measurements were determined using CT scans of 260 normal livers. These measurements include the area and volume, and the length, width, and girth of the liver (IRB HUM00041441). To characterize geometrical shape, an inscribed sphere and circumscribed ellipsoid were fitted on the measurements. In the pediatric population the liver area and volume continuously increased with age. When normalized by patient weight, volume measurements show a decrease in volume with age, suggesting that the liver occupies a smaller proportion of the body with age. In the adult population, liver measurements varied with gender. The superior and inferior locations of the liver were also recorded with respect to the spine. The lower portion was at the L3 in small children and at L2 as children approached puberty. It stayed in that area through the 60+ group, offering more ribcage protection. Liver injury patterns were also assessed in crash occupants. Seventy-two occupants with moderate to severe (AIS 2+) liver injuries were investigated. A new methodology was presented and consisted of quantifying blood volumes. The results were compared to overall liver volume and injury scales. No clear distinction on the injury pattern was observed by age group. Liver injuries were more commonly associated with AIS 2+ thoracic injuries in adults than in children. Most injuries occurred in the right lobe.