Ontogeny of cranial base during the first two years of life.

The integration of the growth of the brain and the cranial base suggests that each system may influence the other, notably during the first three years of life, although this influence has never been proven to be exclusive. The aim of our work was to analyse the dynamics of normal growth on the one hand, and the development and ontogenetic allometry of the cranial base in the infant on the other hand. MATERIAL AND METHOD: A total of 32 infants (17 males/15 femeles) having been included in the unexpected infant death french protocol were analyzed. Three-dimensional reconstructions of the cranial base were performed from CT scans. The technique combined manual segmentation of regions of interest, contour extraction and surface reconstruction. Nineteen landmarks were positioned on each of the bone surfaces. RESULTS: No correlation was observed between sex assigned at birth and shape, weight, crown-heel length, or head circumference. Principal component analysis showed that 85.5% of the variance observed on the first component was secondary to growth. After Procrustes superimposition, 25% of the shape variance observed was explained by the first principal component. It showed anteroposterior lengthening of the cranial base. In addition, the height, width and length of the posterior fossa increased and the relative position of the basion was displaced inferiorly and anteriorly with flexion of the sphenoid angle. Negative allometry was also observed. CONCLUSION: Our study, carried out in a rigorously selected population of infants, presents a fundamental approach to ontogeny through study of shape, growth and ontogenetic allometry.

Study of the growth and shape of the brain and cranial base during the first two years of life.

Ontogeny of the cranial base and the brain integrates data on growth, maturation and ontogenetic allometry of these two systems in the course of development. The aim of our work was to study the ontogeny of the cranial base and the brain in order to understand their growth dynamic and shape changes using a traditional morphometric approach in individuals with normal (non-pathological) development. MATERIEL AND METHOD: Forty-seven infants having been included in the unexpected infant death french protocol were analyzed. Medical imaging (CT and MRI) exams, followed by an autopsy and pathology examination allowed us to include only infants free from brain disease or pathology affecting growth. RESULTS: Testing of measurement reliability validated 12 distances and 3 angles as well as the positioning of the landmarks that had been used to obtain the distances and the angles. No correlation between sex and the various variables studied was found. However, a correlation was observed between these variables and age, making it possible to propose a growth curve. A medium to strong correlation was found between brain variables and the bone variables of the cranial base, underlining the parallel development of the two systems. CONCLUSION: Our study, carried out in a rigorously selected population of infants, presents a fundamental approach to the study of ontogenesis.

Diagnostic value of unenhanced postmortem computed tomography in the detection of traumatic abdominal injuries.

OBJECTIVE: To determine the diagnostic capabilities of unenhanced postmortem computed tomography (UPMCT) in detecting traumatic abdominal injuries. MATERIAL AND METHODS: Cases of traumatic death with both UPMCT and classical autopsy were collected retrospectively from our institution "virtopsy" database in a period of 5 years. Cadavers with gunshot injuries were excluded. Sensitivity, specificity, accuracy, negative (NPV) and positive (PPV) predictive values of PMCT globally and for hemoperitoneum, liver, spleen, pancreas and kidney injuries individually were estimated using the autopsy report as gold standard. RESULTS: Seventy-one cadavers were included. UPMCT had a sensitivity of 80% and a specificity 94%, with an accuracy of 83%, a PPV of 98% and a NPV of 59% for the diagnosis of traumatic abdominal injuries. The highest sensitivity was obtained for the detection of hepatic injuries (71%) and the lowest for pancreatic injuries (12%). UPMCT had a specificity of 100% for the detection of hemoperitoneum. A NPV of 98% was found for the detection of perihepatic hematomas. CONCLUSION: The low sensitivity and low NPV do not support the use of UPMCT as an alternative to conventional autopsy to diagnose and/or rule out traumatic abdominal injuries. Nevertheless, UPMCT remains a helpful tool as it helps detect hemoperitoneum and virtually exclude presence of perihepatic hematomas.