ABSTRACT
PURPOSE: The purpose of this study was to assess the apparent diffusion coefficient (ADC) of neuroblastic tumours and to evaluate if the ADC can enable differentiation of neuroblastoma and ganglioneuroma/ganglioneuroblastoma. PATIENTS AND METHODS: 16 histologically classified tumours (10 neuroblastomas and 6 ganglioneuroma/ganglioneuroblastoma) were investigated in 15 children. Diffusion-weighted echo-planar imaging was performed with a b-value of 800s/mm². The contrast of tumour tissue depicted with T2-weighted images and diffusion-weighted images was evaluated by means of region-of-interest (ROI) measurements and a calculation of the ADC by a software tool. The ADC of the psoas-muscle was measured to establish an internal standard, too. RESULTS: The mean ADC of the 10 neuroblastomas was 0.81×10⻳mm²/s (SD 0.29×10⻳mm²/s, range 0.39-1.47×10⻳)mm²/s). The mean ADC of the four ganglioneuroma and two ganglioneuroblastoma was 1.6×10⻳mm²/s (SD 0.340×10⻳mm²/s, range 1.13-1.99)×10⻳mm²/s. The difference was significant in the t-test (p=0.01). We found no ganglioneuroma or ganglioneuroblastoma with an ADC below 1.1×10⻳mm²/s. DISCUSSION: There is a significant difference of the ADC of neuroblastoma compared to the ADC of ganglioneuroma/ganglioneuroblastoma. These first results suggest that the diffusion-weighted imaging could differentiate neuroblastoma and ganglioneuroma/ganglioneuroblastoma by calculating the ADC.
