Quantitative measurement of blood flow in paediatric brain tumours—a comparative study of dynamic susceptibility contrast and multi time-point arterial spin labelled MRI

Abstract

Objective:Arterial spin-labelling (ASL) MRI uses intrinsic blood water to quantify the cerebral blood flow (CBF), removing the need for the injection of a gadolinium-based contrast agent used for conventional perfusion imaging such as dynamic susceptibility contrast (DSC). Owing to the non-invasive nature of the technique, ASL is an attractive option for use in paediatric patients. This work compared DSC and multi-timepoint ASL measures of CBF in paediatric brain tumours.Methods:Patients (n = 23; 20 low-grade tumours and 3 high-grade tumours) had DSC and multi-timepoint ASL with and without vascular crushers (VC). VC removes the contribution from larger vessel blood flow. Mean perfusion metrics were extracted from control and T1-enhanced tumour regions of interest (ROIs): arterial arrival time (AAT) and CBF from the ASL images with and without VC, relative cerebral blood flow (rCBF), relative cerebral blood volume, delay time (DT) and mean transit time (MTT) from the DSC images.Results:Significant correlations existed for: AAT and DT (r = 0.77, p = 0.0002) and CBF and rCBF (r = 0.56, p = 0.02) in control ROIs for ASL-noVC. No significant correlations existed between DSC and ASL measures in the tumour region. Significant differences between control and tumour ROI were found for MTT (p < 0.001) and rCBF (p < 0.005) measures.Conclusion:Significant correlations between ASL-noVC and DSC measures in the normal brain suggest that DSC is most sensitive to macrovascular blood flow. The absence of significant correlations within the tumour ROI suggests that ASL is sensitive to different physiological mechanisms compared with DSC measures.Advances in knowledge:ASL provides information which is comparable with that of DSC in healthy tissues, but appears to reflect a different physiology in tumour tissues.

Arterial Spin-Labeling in Children with Brain Tumor: A Meta-Analysis

“…Eight studies including 286 patients were included in the meta-analysis. 17,[27][28][29][30][31][32][33] The study selection is presented in the On-line Figure 1.…”

“…17,[27][28][29]32,33 Two studies used pulsed ASL. 30,31 Four of 8 studies used 1.5T, with the remaining using 3T. Risk of bias within studies as assessed by the QUADAS-2 tool, which showed a general low or indeterminate risk of bias (Fig 1).…”

“…High risk of bias was attributed to undefined blinding procedures when analyzing the ASL data and applying the exploratory cutoff determination in 5 of 8 studies. [28][29][30][31]33 High risk of applicability concern was found in 3 studies [29][30][31] : One study did not report a clear description of the reference standard, 29 and 2 studies applied pulsed ASL 30,31 as well as a unique (for the meta-analysis cohort) postprocessing method of vascular crushing. 31 Applicability concerns were taken into account in the subgroup analyses by stepwise exclusion.…”

Treatment of Pediatric Brain Tumors in Brazzaville (Congo) about a Case Series

“…Tumors of the central nervous system are the most common group of solid tumors in children and account for 20% to 25% of childhood neoplasms [1] [2] [3]. In the United States, mortality rates among children with brain tumors exceed those in children with acute lymphoblastic leukemia [1]. Magnetic Radiologic Imaging (MRI) is the required non-invasive investigation for the diagnosis of brain tumors.…”

“…There are different types with variable survival rates depending on the histology, biology, age, and degree of spread. Some types of brain tumors may be completely resected, many cannot be removed without a considerable degree of morbidity [1].…”