Haller index或稱凹陷指數，常用於漏斗胸（pectus excavatum）的嚴重度評估，是由Dr. Haller等人在1987年所提出來的方法，圖中A為白色橫向雙箭頭線長度；B、D分別為左右兩側白色縱向雙箭頭線長度；C為中間黑色縱向雙箭頭線長度；E為中間白色縱向雙箭頭線長度，則Haller index為何？

Haller 指數 (Haller index) 定義為胸腔最寬內側肋緣間距離（即圖中 A）與胸骨最凹點至脊椎前表面最短距離（即圖中 C）之比值，因此正確答案為 A/C，對應選項 A。

引用：
– “The Haller index is calculated by dividing the transverse diameter (the distance across the chest) by the anteroposterior diameter (the distance from the sternum to the spine).” (en.wikipedia.org)
– “Haller index is: transverse diameter of chest (inner rib to inner rib) divided by AP diameter of chest (back of sternum to anterior part of vertebral body).” ([pediatricimaging.org](https://pediatricimaging.org/diseases/pectus-e

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