Fig. 13.

Using DWI following canal wall down surgery. In a patient who presented with persistent otorrhoea after CWD surgery, a the DWI b1000 images show high signal in the mastoid remnants bilaterally, which corresponded to infected debris/wax on clinical inspection. b On direct clinical inspection of the left mastoid remnant, which showed the infected debris/wax (white arrow), a bony defect (black arrow) is noted on the medial wall above the bony labyrinth. The defect communicated with extensive residual cholesteatoma hidden deep in the petrous apex, which was demonstrated by high signal soft tissue (white arrow) on the coronal c T2 weighted and d b1000 images