Disclosed herein is an apparatus comprising an insertion tube； an image sensor inside the insertion tube； wherein the image sensor comprises an array of pixels； wherein the image sensor is configured to count numbers of particles of radiation incident on the pixels, within a period of time. Also disclosed herein is a method of using this apparatus.本文公開了一種裝置，該裝置包含插入管；影像感測器在插入管內；所述影像感測器包含有像素陣列；其中所述影像感測器被配置為在一段時間內對入射在所述像素上的輻射粒子的數量進行計數。本文還公開了使用該裝置的方法。
