ZUSAMMENFASSUNGZiel Untersucht wurde die diagnostische Aussagekraft der diffusionsgewichteten MRT (DWI) für die Tumorcharakterisierung, Tumordifferenzierung und Verlaufskontrolle bei Kindern mit extrakraniellen neuroblastischen Tumoren. Alle 29 Patienten (14 Mädchen, medianes Alter 3 Jahre) mit Neuroblastom (NB, n = 19), Ganglioneuroblastom (GNB, n = 4) und Ganglioneurom (GN, n = 6) This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Material und Methoden ABSTR AC T PurposeWe explored the diagnostic value of diffusionweighted MRI (DWI) for tumor characterization, differentiation and therapy monitoring in pediatric patients with extracranial neuroblastic tumors. Materials and MethodsAll 29 patients (14 girls, median age: 3 years) with neuroblastoma (NB, n = 19), ganglioneuroblastoma (GNB, n = 4) and ganglioneuroma (GN, n = 6) who had had at least one in-house DWI examination since 2005 were identified and retrospectively analyzed. Two independent blinded readers measured ADC values (unit: 10−3 mm 2 /s) and signal intensity ratios (SIRs) of the primary tumor and, if applicable, of the tumor after chemotherapy, metastases and tumor relapse.Results The pre-treatment ADC was 0.90 ± 0.23 in NB/GNB and 1.70 ± 0.36 in GN without overlap between the two entities for both readers, 0.67 ± 0.14 in metastases and 0.72 ± 0.18 in tumor relapse. With chemotherapy, mean ADC increased to 1.54 ± 0.33 in NB/GNB and to 1.23 ± 0.27 in metastases (p < 0.05). The median SIRs of various tumor lesions vs. liver, vs. muscle tissue and vs. adjacent tissue were significantly higher on DWI (range: 2.4 -9.9) than on ce-T1w (range: 1.0 -1.8, all p < 0.05). The coefficient of variation (CV) was ≤ 8.0 % for ADC and ≤ 16.4 % for signal intensity data.Conclusion Based on mean ADC, DWI distinguishes between NB/GNB and GN with high certainty and provides plausible quantitative data on tumor response to therapy. Lesion conspicuity, as measured by SIR, is superior on DWI, compared to ce-T1w. DWI as a noninvasive, radiation-free and widely available imaging technique should be an integral part of MR imaging for neuroblastic tumors and should undergo prospective evaluation in multicenter studies. Key Points▪ DWI reliably distinguishes neuroblastoma/ganglioneuroblastoma from ganglioneuroma, based on the mean ADC. ▪ DWI provides plausible quantitative data on tumor response to chemotherapy. ▪ DWI offers highly superior lesion conspicuity compared to contrast-enhanced T1w imaging. ▪ DWI should be considered a standard for imaging neuro-

Cochlear implant (CI) recipients are limited in their perception of voice cues, such as the fundamental frequency (F0). This has important consequences for speech recognition when several talkers speak simultaneously. This examination considered the comparison of clear speech and noise-vocoded sentences as maskers. For the speech maskers it could be shown that good CI performers are able to benefit from F0 differences between target and masker. This was due to the fact that a F0 difference of 80 Hz significantly reduced target-masker confusions, an effect that was slightly more pronounced in bimodal than in bilateral users.

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