The effect of diffusion MRI acquisition settings on Rhabdomyosarcoma images: a multicenter study

Abstract

Rhabdomyosarcoma (RMS) is a soft tissue tumor that originates from the muscle cells. It is a rare tumor, therefore a multicenter study is needed to gather a sufficiently large amount of images. In this study, we compared two datasets of diffusion weighted images (DWI) coming from a single center in the Netherlands and from centers across Europe. The databases, respectively of 51 and 126 images from 25 and 73 patients. Acquisition parameters and patient information were analyzed to quantify inter and intra center variability and the effect of those on mean apparent diffusion coefficient (ADC). From the two datasets, high variability has been observed in acquisition parameters and patients’ information. No particular links to the ADC values was found, possibly due to the large amount of data missing from some of the images, especially b-values. In the second part of the study, a DWI scan on a healthy subject was performed using echo time, voxel dimension and b-values most commonly found in the datasets. Varying one parameter at a time and keeping the other fixed, a total of 10 images were acquired. The aim was to isolate the effect of each acquisition parameter on mean ADC and differences from 1.0% up to 17.7% were found in mean ADC. These findings show how important it is to adhere to a strict set of acquisition parameters, in order to minimize as much as possible their variability and influence on ADC values.