Arterial input function and gray matter cerebral blood volume measurements in children
Stephanie B Withey1,2,3, Jan Novak2,3, Lesley MacPherson2
1RRPPS, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
Insights
Arterial input functions (AIFs) in pediatric dynamic susceptibility contrast MRI vary with age. Individual AIFs are recommended for accurate gray matter cerebral blood volume (CBV) calculations in children.
Area of Science:
- Neuroimaging
- Pediatric Radiology
- Medical Physics
Background:
- Quantitative cerebral blood volume (CBV) measurement using dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) relies on accurate arterial input function (AIF) data.
- AIFs are known to be influenced by patient age, yet limited data exists for the pediatric population.
Purpose of the Study:
- To investigate age-related variations in AIFs in children.
- To compare the accuracy of individual versus population AIFs for calculating gray matter CBV in pediatric DSC-MRI studies.
Main Methods:
- DSC-MRI scans were performed on 22 pediatric brain tumor patients (age range: 2.0-15.3 years).
- AIFs were measured in the middle cerebral artery and fitted to a functional form to analyze shape parameters.
- Correlations between AIF shape parameters and patient age were assessed, along with CBV calculation differences using individual and population AIFs.
Main Results:
- Significant correlations were observed between AIF shape parameters (peak center and width) and patient age.
- Intrapatient AIF variability was considerably lower than interpatient variability.
- CBV values calculated using population AIFs differed by approximately 31% compared to those derived from individual AIFs.
Conclusions:
- AIF shape parameters in pediatric patients are age-dependent, reflecting physiological changes.
- The use of individual patient AIFs is recommended for precise gray matter CBV quantification in pediatric DSC-MRI.
Purpose:
To investigate how arterial input functions (AIFs) vary with age in children and compare the use of individual and population AIFs for calculating gray matter CBV values. Quantitative measures of cerebral blood volume (CBV) using dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) require measurement of an AIF. AIFs are affected by numerous factors including patient age. Few data presenting AIFs in the pediatric population exists.
Materials And Methods:
Twenty-two previously treated pediatric brain tumor patients (mean age, 6.3 years; range, 2.0-15.3 years) underwent DSC-MRI scans on a 3T MRI scanner over 36 visits. AIFs were measured in the middle cerebral artery. A functional form of an adult population AIF was fitted to each AIF to obtain parameters reflecting AIF shape. The relationship between parameters and age was assessed. Correlations between gray matter CBV values calculated using the resulting population and individual patient AIFs were explored.
Results:
There was a large variation in individual patient AIFs but correlations between AIF shape and age were observed. The center (r = 0.596, P < 0.001) and width of the first-pass peak (r = 0.441, P = 0.007) were found to correlate significantly with age. Intrapatient coefficients of variation were significantly lower than interpatient values for all parameters (P < 0.001). Differences in CBV values calculated with an overall population and age-specific population AIF compared to those calculated with individual AIFs were 31.3% and 31.0%, respectively.
Conclusion:
Parameters describing AIF shape correlate with patient age in line with expected changes in cardiac output. In pediatric DSC-MRI studies individual patient AIFs are recommended.
