Localization of active otosclerotic foci by tympano-cochlear scintigraphy (TCS) using correlative imaging.

High-resolution, tympano-cochlear scintigraphy (TCS) is a useful tool for visualizing changes in labyrinthine bone metabolism in active otosclerosis in vivo. But until now, the activity patterns have mostly been rather imprecisely ascribed to the labyrinthine structures; more exactly by means of high-resolution CT (HR-CT). Experimental studies on TCS using a human temporal bone model revealed that correlative imaging of X-ray photographs and the scintigrams or superimposition with masks of the temporal bone drawn from the X-rays can facilitate the localization of small foci of about 0.5-1 mm. Clinical applications of the visualization technique, combining functional with structural images, confirmed the benefit of this method, improving the accuracy in detection and localization of focal activity enrichment of the petrous bone in cases of active otosclerosis by means of TCS.