A method for determining variations among multiple three-dimensional stone images extracorporeally and a computer program product using the method are disclosed. The method involves during a lithotripsy process performed on a human body, multiple three-dimensional stone images taken from a stone location in the human body are processed outside the human body using the following steps: using a processing unit to execute a computing process for the multiple three-dimensional stone images one by one in an order from the first taken said image to the last taken said image, wherein the computing process involves using an entropy texture equation or an inverse difference moment (IDM) texture equation to calculate a texture feature value for each said three-dimensional stone image and when the texture feature values calculated using the entropy texture equation or the inverse difference moment (IDM) texture equation substantively stop changing, making the processing unit output a prompt signal.本發明係為一種在體外判斷多幅三維結石影像間之差異之方法及電腦程式產品,該方法係根據在對人體執行碎石過程中,對結石部位所依序獲得的多幅之三維結石影像,在人體外執行以下步驟:A. 由一處理單元對該多幅的三維結石影像,依取得時間之先後順序分別逐一執行一運算程序,該運算程序係分別以一熵(Entropy)紋理運算式或一逆差矩(IDM)紋理運算式計算每一三維結石影像之一紋理特徵值;B. 當該熵(Entropy)紋理運算式或該逆差矩(IDM)紋理運算式所計算的紋理特徵值實質上不再變化時,由該處理單元輸出一提示訊號。藉由運算多幅的三維結石影像的紋理特徵值,並觀察三維結石影像的紋理特徵值所產生的變化,藉此在人體外判斷多幅三維結石影像間之差異。