MRI findings related to Image Defined Risk Factors (IDRFs) in children with neuroblastic tumours: Analysis for structured reporting

Abstract

Neuroblastic tumours constitute a heterogenous group of tumours with diverse presentation, variable malignant behaviour and prognosis. Image Defined Risk Factors (IDRFs) have been described in the International Neuroblastoma Risk Group Staging System (INRGSS). IDRFs refer to compartmental involvement, the effect of masses to vital organs or anatomic structures and their relation to neurovascular bundles and airway. CT has been traditionally recommended for imaging children with neuroblastoma. MRI is increasingly being utilised for the diagnosis, staging and follow-up of children with neuroblastic tumours and is considered an acceptable modality for clinical trials. Appropriate structured reporting is crucial for communication with surgeons. This pictorial essay focuses on the MRI appearances of neuroblastic tumours, aims to familiarise radiologists with relevant terminology and the routine use of IDRFs when reporting MR imaging studies preoperatively; it provides a concise checklist of the INRGSS relevant parameters for complete preoperative assessment of children with neuroblastic tumours. This terminology and approach may also prove useful for reporting not only neuroblastic tumours but abdominal paediatric tumours in general.