The rib index practically is not affected by the distance between the radiation source and the examined child

Theodoros B Grivas,Antonios Akriotis,Vasileios Kechagias,Konstandinos Soultanis,Christina Mazioti,Konstandinos Athanasopoulos,Christos Naskas

doi:10.1186/1748-7161-10-s1-o44

Abstract

All lateral spinal radiographs in idiopathic scoliosis (IS) show a Double Rib Contour Sign (DRCS) of the thoracic cage, a radiographic expression of the rib hump. The outline of the convex overlies the contour of the concave ribs. The rib index (RI) method was extracted from the DRCS to evaluate rib hump deformity in IS patients. The RI was calculated by the ratio of spine distances d1/d2 where d1 is the distance between the most extended point of the most extending rib contour and the posterior margin of the corresponding vertebra on the lateral scoliosis films, while d2 is the distance from the least projection rib contour and the posterior margin of the same vertebra, (Grivas et al 2002). In a symmetric thorax the “rib index” is 1.

Highlights

All lateral spinal radiographs in idiopathic scoliosis (IS) show a Double Rib Contour Sign (DRCS) of the thoracic cage, a radiographic expression of the rib hump
The rib index (RI) was calculated by the ratio of spine distances d1/d2 where d1 is the distance between the most extended point of the most extending rib contour and the posterior margin of the corresponding vertebra on the lateral scoliosis films, while d2 is the distance from the least projection rib contour and the posterior margin of the same vertebra, (Grivas et al 2002)
Using the Euclidean geometry (Figure 1) it is shown that in a normal child 12 years of age, provided that the distance ΔZ ≈ 12cm (11,84) and EA = 180cm, with transverse ribcage diameter of the child 22 cm, d1/d2 = 1.073. This validity study demonstrates that the DRCS is substantially true and practically the RI is not affected by

Summary

Introduction

Introduction All lateral spinal radiographs in idiopathic scoliosis (IS) show a Double Rib Contour Sign (DRCS) of the thoracic cage, a radiographic expression of the rib hump. The outline of the convex overlies the contour of the concave ribs. The rib index (RI) method was extracted from the DRCS to evaluate rib hump deformity in IS patients.

Results

Conclusion