RESUMO
Purpose We explored the diagnostic value of diffusion-weighted MRI (DWI) for tumor characterization, differentiation and therapy monitoring in pediatric patients with extracranial neuroblastic tumors. Materials and Methods All 29 patients (14 girls, median age: 3 years) with neuroblastoma (NB, nâ=â19), ganglioneuroblastoma (GNB, nâ=â4) and ganglioneuroma (GN, nâ=â6) 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: 10-3âmm2/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 0.90â±â0.23 in NB/GNB and 1.70â±â0.36 in GN without overlap between the two entities for both readers, 0.67â±â0.14 in metastases and 0.72â±â0.18 in tumor relapse. With chemotherapy, mean ADC increased to 1.54â±â0.33 in NB/GNB and to 1.23â±â0.27 in metastases (pâ<â0.05). The median SIRs of various tumor lesions vs. liver, vs. muscle tissue and vs. adjacent tissue were significantly higher on DWI (range: 2.4â-â9.9) than on ce-T1w (range: 1.0â-â1.8, all pâ<â0.05). The coefficient of variation (CV) was ≤â8.0â% for ADC and ≤â16.4â% 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 neuroblastic tumors.. Citation Format · Neubauer H, Li M, Müller VR etâal. Diagnostic Value of Diffusion-Weighted MRI for Tumor Characterization, Differentiation and Monitoring in Pediatric Patients with Neuroblastic Tumors. Fortschr Röntgenstr 2017; 189: 640â-â650.