When acute mastoiditis occurs in cochlear implant recipients, it can progress to subsequent retroauricular abscess due to the absence of the external mastoid cortex resulting from mastoidectomy performed for cochlear implantation. The management goal is to control infection while preserving the implanted device. A 2-year-old boy with cochlear implants developed acute mastoiditis and a subsequent retroauricular abscess. The patient underwent a surgical intervention based on the diagnosis made utilizing gray-scale and power Doppler sonography. This case illustrates the diagnostic usefulness of sonography in this rare situation. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound, 2017.

作者：Hiroshi, Sakaida；Satoko, Usui；Yasunori, Matsuda；Sawako, Masuda；Kazuhiko, Takeuchi

来源：Journal of clinical ultrasound : JCU 2017 年