ROLE OF MODERN IMAGING TECHNOLOGY IN THE IMPLEMENTATION OF PEDIATRIC COCHLEAR IMPLANTS

Since 1989, 40 patients have received cochlear implants in our institu tion. Over the past 2 years, 17 children among these patients have und ergone radiographic assessment combining magnetic resonance imaging (M RT) and high-resolution computed tomography (CT) scanning. Imaging is not essential, and is only used after assessment by a multidisciplinar y team. However, the imaging results influence the choice of implant, and sometimes the side to be implanted. The first study is always CT, as it detects congenital abnormalities, and for children with a histor y of bacterial meningitis, it can detect signs of labyrinthine ossific ation that contraindicates or complicates cochlear implantation. These signs are not always visible with tomodensitometry, especially when f ibrosis within the canal has not yet ossified. This examination also p rovides for postoperative confirmation of implant position in case of failure or complication. Over the past 3 years, MRI has been combined with tomodensitometry, especially with children having a history of me ningitis. This examination provides a basis for evaluating the liquid nature of the labyrinth. A GE Signa 1.5-T unit was used by the authors , employing sequences of volumetric acquisition (steady state free pre cision with 1.5-mm image slices and an angle of 15 degrees to 35 degre es). Hence, modern imaging plays an important role when the decision t o implant has already been made, particularly in the case of profoundl y deaf children. We always use MRI in combination with a CT scanner in children with a history of meningitis.