Arterial spin labelling and diffusion-weighted imaging in paediatric brain tumours

Area of Science:

• Radiology
• Neuro-oncology
• Medical Imaging

Background:

• Childhood brain tumours have unique biological features distinct from adult tumours.
• Paediatric-focused MRI studies assessing tumour characteristics are less common.
• Diffusion- and perfusion-weighted MRI offer insights into cellular and vascular properties.

Purpose of the Study:

• To evaluate the diagnostic utility of apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) values in paediatric brain tumours.
• To establish typical parameter ranges for different tumour subtypes and WHO grades.
• To validate findings in a new cohort of paediatric patients.

Main Methods:

• A meta-analysis of 14 published studies (542 patients) was conducted.
• A validation cohort of 32 treatment-naïve paediatric brain tumour patients was acquired.
• Apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) values were quantified using manual and automated region of interest (ROI) placement.

Main Results:

• Significant differences in ADC and CBF values were observed across histological tumour subtypes and WHO grades.
• Diffuse midline glioma showed atypical ADC and CBF values, resembling low-grade tumours.
• Optimized thresholds for differentiating low/high-grade tumours (excluding diffuse midline glioma) achieved high accuracy (96% for ADCmean, 83% for ADCmin, 83% for nCBFmax).
• Combining ADC and CBF measurements achieved 100% accuracy in classifying tumour grade in the validation cohort.

Conclusions:

• ADC and CBF values are effective in differentiating paediatric brain tumour subtypes and grades.
• The established threshold values align with previous research and are validated in a new cohort.
• Combining ADC and CBF measurements significantly optimizes diagnostic accuracy for paediatric brain tumours.