Investigations

Magnetic resonance imaging (MRI) of the brain is the preferred test and is the diagnostic standard for evaluation of the tumour and assessment of associated brain or spinal metastases.(1)

CT is useful for rapid assessment in the acute setting, or if MRI is unavailable/contraindicated.

The advantages of CT over MRI are that it is quicker, does not require sedation, and is easier to obtain urgently. The advantage of MRI over CT is that it gives a better anatomical view of the brain with no exposure to radiation.(2) CT is not appropriate for staging tumours.​

Advanced imaging with MR spectroscopy (MRS) can help differentiate medulloblastomas from other posterior fossa tumours, as high levels of taurine at 3.4 ppm are almost exclusively found in medulloblastomas. (2)

Reference

1. Gajjar A et al. Pediatric Central Nervous System Cancers, Version 2.2025, NCCN Clinical Practice Guidelines In Oncology. J Natl Compr Canc Netw. 2025 Mar;23(3):113-130.
2. Dangouloff-Ros V et al. Imaging features of medulloblastoma: Conventional imaging, diffusion-weighted imaging, perfusion-weighted imaging, and spectroscopy: From general features to subtypes and characteristics. Neurochirurgie. 2021 Feb;67(1):6-13.