1.Evaluation of Tumor Blood Flow Using Alternate Ascending/Descending Directional Navigation in Primary Brain Tumors: A Comparison Study with Dynamic Susceptibility Contrast Magnetic Resonance Imaging
Hyeree PARK ; Joonhyuk LEE ; Sung Hong PARK ; Seung Hong CHOI
Korean Journal of Radiology 2019;20(2):275-282
OBJECTIVE: Alternate ascending/descending directional navigation (ALADDIN) is a novel arterial spin labeling technique that does not require a separate spin preparation pulse. We sought to compare the normalized cerebral blood flow (nCBF) values obtained by ALADDIN and dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) in patients with primary brain tumors. MATERIALS AND METHODS: Sixteen patients with primary brain tumors underwent MRI scans including contrast-enhanced T1-weighted imaging, DSC perfusion MRI, and ALADDIN. The nCBF values of normal gray matter (GM) and tumor areas were measured by both DSC perfusion MRI and ALADDIN, which were compared by the Wilcoxon signed rank test. Subgroup analyses according to pathology were performed with the Wilcoxon signed rank test. RESULTS: Higher mean nCBF values of GM regions in the bilateral frontal lobe, temporal lobe, and caudate were detected by ALADDIN than by DSC perfusion MRI (p <0.05). In terms of the mean or median nCBF values and the mean of the top 10% nCBF values from tumors, DSC perfusion MRI and ALADDIN did not statistically significantly differ either overall or in each tumor group. CONCLUSION: ALADDIN tended to detect higher nCBF values in normal GM, as well as higher perfusion portions of primary brain tumors, than did DSC perfusion MRI. We believe that the high perfusion signal on ALADDIN can be beneficial in lesion detection and characterization.
Brain Neoplasms
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Cerebrovascular Circulation
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Frontal Lobe
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Glioma
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Gray Matter
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Humans
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Magnetic Resonance Angiography
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Magnetic Resonance Imaging
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Pathology
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Perfusion
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Temporal Lobe
2.A Simple Method for Generating Cerebral Organoids from Human Pluripotent Stem Cells
Yean Ju HONG ; So been LEE ; Joonhyuk CHOI ; Sang Hoon YOON ; Jeong Tae DO
International Journal of Stem Cells 2022;15(1):95-103
Background and Objectives:
In recent years, brain organoid technologies have been the most innovative advance inneural differentiation research. In line with this, we optimized a method to establish cerebral organoids from feeder-free cultured human pluripotent stem cells. In this study, we focused on the consistent and robust production of cerebral organoids comprising neural progenitor cells and neurons. We propose an optimal protocol for cerebral organoid generation that is applicable to both human embryonic stem cells and human induced pluripotent stem cells.
Methods:
and Results: We investigated formation of neuroepithelium, neural tube, and neural folding by observing the morphology of embryoid bodies at each stage during the cerebral organoid differentiation process. Furthermore, we characterized the cerebral organoids via immunocytochemical staining of sectioned organoid samples, which were prepared using a Cryostat and Vibratome. Finally, we established a routine method to generate early cerebral organoids comprising a cortical layer and a neural progenitor zone.
Conclusions
We developed an optimized methodology for the generation of cerebral organoids using hESCs and hiPSCs. Using this protocol, consistent and efficient cerebral organoids could be obtained from hiPSCs as well as hESCs. Further, the morphology of brain organoids could be analyzed through 2D monitoring via immunostaining and tissue sectioning, or through 3D monitoring by whole tissue staining after clarification.