Article
CHEN Yi, LIU Ming, GUAN Wenbin, ZHANG Peirong, ZHENG Hui, ZHANG Haibo
Objective: To explore the clinical and imaging features of diffuse high-grade gliomas in the brainstem of children based on multi parameter sequences, so as to improve the comprehensive understanding of the disease. Methods: The clinical and imaging data of pediatric brain stem diffuse high-grade gliomas confirmed by pathology from January 2022 to January 2024 were retrospectively analyzed. Results: A total of 45 children in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine with diffuse high-grade gliomas in the brainstem (19 males and 26 females, aged 6.48±2.34 years) were included in this study. Among them, 4.4% (2/45) had cerebrospinal fluid dissemination, while the rest had localized or nearby infiltration and growth in the brainstem. 45 cases underwent computed tomography (CT) plain scan+ magnetic resonance imaging (MRI) plain scan/enhanced scan+diffusion-weighted imaging (DWI) basic scan, 6 cases underwent CT perfusion imaging (CTP) scan simultaneously, 8 cases underwent magnetic resonance spectroscopy (MRS) scan simultaneously, 7 cases underwent diffusion tensor imaging (DTI) scan simultaneously, and 2 cases underwent susceptibility weighted imaging (SWI) scan simultaneously. All 45 cases had endogenous swelling growth, including 36 cases with uniform swelling growth on both sides and 9 cases with lateral swelling growth (7 cases crossed the midline during the growth process, and 2 cases with diffuse growth on one side of the head and tail); 28.9% (13/45) limited brainstem growth, 2.2% (1/45) limited medullary growth, 68.9% (31/45) grew towards the head and tail (midbrain/thalamus/medulla oblongata, 21/31, 67.7%) and laterally (pons/cerebellum, 10/31, 32.3%), and 26.7% (12/45) progressed to exogeneity (including 11 cases involving the basilar artery, 11/12, 91.7%). The CT plain scan sequence showed low-density thickening shadows in the brainstem area, with a density lower than that of the normal brainstem (P<0.001). CT perfusion sequence scan showed a decrease in cerebral blood flow (CBF) in the tumor area of 83.3% (5/6) of patients (1 case showed a significantly lower than average level in the tumor center area), and 1 case showed an increase. Bilateral cerebral hemisphere perfusion abnormalities, with delayed peak time, mainly around the lateral ventricles. The MRI structural sequence showed that 8.9% (4/45) of the tumor solid components on T1-weighted imaging (T1WI) showed equal signal intensity, 11.1% (5/45) showed low signal intensity, and 80.0% showed mixed signal intensity (36/45). The T2-fluid suppressed inversion recovery (FLAIR) sequence showed slightly high to high signal intensity, and the pattern after T1WI enhancement showed diverse changes. Six cases did not show enhancement, while the rest showed varying degrees of mild to moderate enhancement. 28.2% (11/39) showed local circular enhancement, 38.5% (15/39) showed local nodular enhancement, 10.3% (4/39) showed patchy enhancement, and 23.1% (9/39) showed patchy enhancement. Manifested as gravel like enhancement, 7.7% (3/39) showed mixed mode enhancement, and some patients with unclear T1WI enhancement had better T2-FLAIR enhancement sequence contrast. In the MRI functional sequence, MRS showed varying degrees of increase in Cho peak and decrease in NAA peak, with one case showing a significant inversion of Lac peak; DTI scan showed that the nerve fiber bundles in the lesion area were pushed to the periphery by the tumor, with 5 cases showing partial interruption of the fiber bundles and 1 case only showing compression and pushing of the fiber bundles. Local low signal can be seen on the SWI phase map, indicating intratumoral microbleeds. Conclusion: The conventional CT findings of diffuse high-grade gliomas in the brain stem of children are low-density brain stem thickening, and quantification is helpful for early detection and prevention of missed diagnosis. The growth mainly occurred in the diffuse endogenetic pontine, and most of them infiltrated and grew to other brain regions along the direction of nerve fiber bundles, pushing or destroying the nearby fiber bundles. The enhancement patterns were various, and most of them were scattered mild to moderate enhancement. There may be cystic image signals inside, which may be related to the reduction of necrosis by local perfusion and absorption after microbleeds;