PA17 Evaluation of magnetic resonance imaging use in paediatric vascular anomalies before and after implementation of local imaging guidance

Abstract

Paediatric vascular anomalies are a group of conditions in which imaging is essential for diagnosis, risk stratification and multidisciplinary management. In the absence of national imaging guidance, practice may vary between centres. Magnetic resonance imaging (MRI) with magnetic resonance angiography (MRA) is frequently requested and, while clinically valuable, has significant implications for radiology resources and exposure to general anaesthesia. A review of local requesting patterns for MRI/MRA was undertaken. Locally developed imaging guidance was created to standardize care. MRI/MRA was recommended for three indications. Firstly, infantile haemangiomas: large ocular or midline lesions, segmental lesions with suspected PHACES, multi­focal haemangiomas and lumbosacral or perineal lesions. Secondly, other vascular tumours: suspected kaposiform haemangioendothelioma, tufted angioma, cutaneous angiosarcoma, large congenital haemangiomas or atypical tumours. Thirdly, vascular malformations: extensive port-wine stains involving the forehead or hemiface, or atypical malformations. We evaluated the appropriateness and diagnostic yield of MRI/MRA requests for paediatric vascular anomalies before and after implementation of locally developed imaging guidance. A retrospective audit was conducted at a tertiary children’s hospital (2023–2025). MRI/MRA requests were assessed for concordance with guidance and diagnostic yield before and after implementation. MRI/MRA utilization remained stable (30.0% before implementation, 28.9% after implementation). Concordance with guidance was high in both cycles (81.1% before implementation, 72.7% after implementation), with variation likely related to sample size. MRI/MRA demonstrated a consistent diagnostic yield of 10%. In the absence of national guidance, use of MRI/MRA in paediatric vascular anomalies was appropriate and consistently high yielding, supporting its role as a targeted, high-value investigation rather than a screening tool. Dermatology-led imaging guidance validated best practice without reducing imaging frequency, reinforcing the importance of specialist clinical judgement. This service evaluation addresses a nationally unmet need, challenges assumptions around MRI/MRA overuse, and provides real-world evidence to inform future BAD-aligned national guidance focused on quality, consistency and value of care.