Role of Dynamic Contrast-Enhanced Perfusion Magnetic Resonance Imaging in Grading of Pediatric Brain Tumors on 3T

Abstract

Background/Aims: Perfusion magnetic resonance imaging (MRI) is useful for preoperative assessment of brain tumors. Dynamic susceptibility contrast perfusion MRI is commonly used for evaluation of brain tumors. Dynamic contrast-enhanced (DCE) MRI is an alternative method that has mainly been used in adult brain tumors. In this preliminary study, we report our initial experience with the DCE perfusion MRI in pediatric brain tumors. Methods: Sixty-four newly diagnosed pediatric brain tumor patients underwent DCE perfusion MRI on a 3-T scanner. Hemodynamic and kinetic parametric maps were generated and the regions with the highest values were measured on each map. Statistical differences were sought to differentiate between low-grade tumors, high-grade tumors, and medulloblastomas. The perfusion metrics of common posterior fossa tumors were also compared. Results: Relative corrected cerebral blood volume (rCBV) and fractional plasma volume measures differed significantly between high- and low-grade tumors (p < 0.05). High-grade tumors could be differentiated from low-grade tumors, with an rCBV cutoff value of 2.41 and 88.6% sensitivity and 65% specificity. There was no significant difference in K^trans, K_ep, V_e, or λ^tr between these 2 groups of tumors. rCBV, relative quantification of the cerebral blood flow, and permeability indices were found to be significantly different in various posterior fossa tumors, i.e., pilocytic astrocytoma, ependymoma, and medulloblastoma (p < 0.05). Conclusion: DCE-derived perfusion metrics are useful in differentiating high-grade tumors from low-grade ones and discriminating among various posterior fossa tumors in the pediatric age group.

Comparative evaluation of cerebral gliomas using rCBV measurements during sequential acquisition of T1-perfusion and T2*-perfusion MRI

“…On the other hand, T1-perfusion is less susceptible to the presence of blood products including hemorrhage, calcification, and artifacts associated with postsurgical changes and expected to give a more accurate assessment of the lesions associated with these issues. [14,15]. In T1-Perfusion, the effect of leakage on rCBV is mitigated by using tracer-kinetic parameters [16,17].…”

Radiohistogenomics of pediatric low-grade neuroepithelial tumors

“…The literature on perfusion parameters of PAs is extremely variable. Some studies show low CBV within the solid component of the PAs [50][51][52], whereas others show high CBV [53,54]. Multiple reasons account for this variance: (a) variability in the perfusion imaging acquisition techniques, (b) use of different algorithms to postprocess the raw perfusion images, and (c) excessive leakiness of the tumor vascularity.…”

“…The results of most of the studies with conventional T2*-weighted perfusion imaging demonstrate lower CBV of the solid component of the PAs than in high-grade gliomas [50][51][52]. CBV measured by T1-weighted perfusion imaging, which is not commonly used in clinical practice, is reportedly higher in PAs than in high-grade gliomas [54]. A study using a simple postprocessing algorithm to process the T2*-weighted raw perfusion images has also reported high CBV in PAs [53].…”

Heterogeneity Diffusion Imaging of gliomas: Initial experience and validation

“…However, anatomical MRI techniques alone are limited for the evaluation of tumor heterogeneity, especially in tumors that demonstrate little or no enhancement. Advanced MRI techniques such as diffusion MRI [3, 4], MR spectroscopy [5, 6] and MR perfusion [7] provide more pathophysiologic information, and they have demonstrated the potential to characterize tumor types and to differentiate recurrent tumor from pseudo progression. Among these advanced techniques, diffusion MRI holds a unique position due to its sensitivity when probing the microenvironment of biological tissues at a cellular level.…”

“…Perfusion MRI provides important diagnostic information about microvascularity within brain tumors, and it can be used to differentiate tumor types and tumor grades [7, 13]. Quantitative and physiologic information provided by diffusion and perfusion MRI are complimentary, and the integration of these two techniques could significantly improve diagnostic confidence [14].…”