New Radiological Index For Pre Operative Evaluation of Chest Deformity

Abstract

Background: Chest deformities have an incidence of 1:1000 live births and with newlinethe wide spectrum of congenital chest wall deformities seen, pectus deformities newlineare by far the most common anterior chest wall deformities. Many international newlineindices have been utilized for evaluation of pectus deformities which aid in newlinecategorizing the chest as normal or deformed. With every index presenting its newlineown limitations and drawbacks, precise radiological assessment parameters newlinedelineating the limits of normal and pathological have not yet been defined. The newlinepresent study has attempted to bring forth a new radiological index for the overall newlinequantitative assessment of pectus deformities, by the inclusion of newlinemanubriosternal joint (MSJT) angulation or position alongside international newlineradiological indices. The influence of MSJT alteration on mediastinal/intrathoracic newlinespace has been assessed by correlating with sterno-vertebral distance newlineand transverse diameter of the chest. Therefore, this study was aimed at newlineevaluating the effectiveness of new radiological index for the diagnosis of the newlinepectus deformities using computed tomography imaging. newlineMaterials and methods: 60 subjects with mild to moderate pectus deformities newlineand 100 controls, with the age group of 1- 40 years were evaluated for the study. newlineNon contrast computed tomography images with sagittal, axial sections were newlineutilized for the measurement of the manubriosternal joint (MSJT) angle, VertebraI newlineindex, Haller s Index, sterno-vertebral distance (SV) and the transverse diameter newlineof the chest (a). Data was tabulated and statistical analysis was performed using newlineANOVA and unpaired student t test. newlineResults: MSJT angulation showed a significant change in pectus deformities in newlinecomparison with controls. Controls with a mean age of 27.05 ± 13.5 showed a newlinemean of 1660 in MSJT angulation, which has reduced significantly to 1590 in newlinepectus excavatum and increased to 1700 in pectus carinatum (plt0.001). The newlinesterno-vertebral distance was increased in pectus carinatum and reduced in newlinepectus excavatum in comparison with controls, which were found statistically newlinesignificant (plt0.001), whereas the transverse diameter of chest showed higher newlinedistance in pectus excavatum and lower distance in pectus carinatum when newlinecompared with controls (plt0001). Therefore, the sterno-vertebral distance had a newlinepositive correlation with MSJT angulation, whereas the transverse diameter of newlinechest showed weak negative correlation. These changes in dimensions and newlineangulations are mainly due to deformation of the key skeletal structures in the newlinethoracic cage. Comparison of international radiological indices in controls and newlinecases, were documented. In pectus carinatum the vertebral index showed a newlinelower mean of 18% and Haller index with ratio of 2.08, whereas in pectus newlineexcavatum the vertebral index had a higher mean of 24% and Haller index with a newline3.2 ratio, which were significantly higher in comparison with controls. newlineConclusion: Angulation at the manubriosternal joint is an important landmark for newlinethe normal chest shape and contour as well. Alteration in the angulation, not just newlinealters the chest shape, but also the internal thoracic dimensions. Therefore, newlineMSJT angulation can be used as an adjunct along with Haller s and/or vertebral newlineindex during radiological evaluation of chest for analyzing pectus deformities. newlineKey words: pectus deformities; manubriosternal angulation; radiological index; newlinechest wall newline newline