文摘
Objectives The objectives are to examine the reproducibility of functional MR imaging in children with solid tumours using quantitative parameters derived from diffusion-weighted (DW-) and dynamic contrast enhanced (DCE-) MRI. Methods Patients under 16-years-of age with confirmed diagnosis of solid tumours (n--7) underwent free-breathing DW-MRI and DCE-MRI on a 1.5?T system, repeated 24?hours later. DW-MRI (6 b-values, 0-1000?sec/mm2) enabled monoexponential apparent diffusion coefficient estimation using all (ADC0-1000) and only ?00?sec/mm2 (ADC100-1000) b-values. DCE-MRI was used to derive the transfer constant (Ktrans), the efflux constant (kep), the extracellular extravascular volume (ve), and the plasma fraction (vp), using a study cohort arterial input function (AIF) and the extended Tofts model. Initial area under the gadolinium enhancement curve and pre-contrast T1 were also calculated. Percentage coefficients of variation (CV) of all parameters were calculated. Results The most reproducible cohort parameters were ADC100-1000 (CV--.26?%), pre-contrast T1 (CV--.21?%), and Ktrans (CV--5.23?%). The ADC100-1000 was more reproducible than ADC0-1000, especially extracranially (CV--.40?% vs. 2.78?%). The AIF (n--) derived from this paediatric population exhibited sharper and earlier first-pass and recirculation peaks compared with the literature’s adult population average. Conclusions Free-breathing functional imaging protocols including DW-MRI and DCE-MRI are well-tolerated in children aged 6 - 15 with good to moderate measurement reproducibility. Key Points -Diffusion MRI protocol is feasible and well-tolerated in a paediatric oncology population. -DCE-MRI for pharmacokinetic evaluation is feasible and well tolerated in a paediatric oncology population. -Paediatric arterial input function (AIF) shows systematic differences from the adult population-average AIF. -Variation of quantitative parameters from paired functional MRI measurements were within 20?%.