弥漫性中线胶质瘤,H3 K27M突变型多模态MRI表现

目的 探讨弥漫性中线胶质瘤，H3 K27M突变型的多模态MRI表现。方法 回顾性分析经术后病理证实的10例弥漫性中线胶质瘤，H3 K27M突变型患者的MR平扫+增强、DWI、动态磁敏感PWI（DSC-PWI）表现，观察肿瘤位置、大小、瘤周水肿、信号特点、扩散情况及强化特点等。结果 10例中，8例病变位于丘脑，1例位于下丘脑，1例位于延髓及颈髓；肿瘤最大径为（5.56±0.42）cm，瘤周水肿范围为（1.33±0.34）cm。T1WI病灶呈低信号，T2WI呈高信号，部分病灶内见散在小斑片状短T1短T2信号，3例肿瘤内见囊变，7例见坏死，7例见出血。增强后9例病变出现明显强化，其中5例为环形强化，3例为结节样强化，1例为斑片状强化；1例未见强化。9例可见不同程度脑积水。DWI显示8例病变不同程度扩散受限，相对平均ADC值为1.26±0.12；相对最小ADC值为1.12±0.12。5例接受DSC-PWI，3例病灶表现为高灌注，1例表现为等灌注，1例表现为低灌注；相对最大脑血容量为2.92±0.49。结论 弥漫性中线胶质瘤，H3 K27M突变型MRI表现多样，但符合高级别胶质瘤MRI表现，确诊需结合分子病理学结果。

Multimodal MRI manifestations of diffuse midline glioma, H3 K27M mutant

Objective To investigate multimodal MRI features of diffuse midline glioma, H3 K27M mutant. Methods Multimodal MRI features, including plain and enhanced MRI, DWI and dynamic susceptibility contrast (DSC)-PWI of 10 patients with pathologically proved diffuse midline glioma, H3 K27M mutant were retrospectively analyzed. The location, size, edema, signal characteristics, diffusion, enhancement characteristics, etc. of the tumors were observed. Results Among 10 patients, 8 lesions located at thalamus, 1 at medulla and cervical cord, 1 at hypothalamus. The mean maximum tumor diameter was (5.56±0.42)cm, and the mean peritumoral edema distance was (1.33±0.34)cm. The tumors appeared as low signal intensity on T1WI and high signal intensity on T2WI, with small patchy short T1 and short T2 signal within lesions. Cystic lesions were observed in 3 lesions, and necrosis and hemorrhage were found in both 7 lesions. Nine lesions demonstrated marked enhancement, with ringlike pattern in 5 lesions, nodular pattern in 3 lesions and patchy pattern in 1 lesion. There was no enhancement in 1 lesion. Hydrocephalus were found in 9 patients. DWI showed restricted diffusion in 8 patients, with mean relative ADC of 1.26±0.12 and minimum relative ADC of 1.12±0.12. In 5 patients who underwent DSC-PWI, markedly high perfusion was demonstrated in 3 patients, moderate perfusion in 1 patient and low perfusion 1 patient demonstrated. The maximum relative cerebral blood volumewas 2.92±0.49. Conclusion Multimodal MRI manifestations of diffuse midline glioma, H3 K27M mutant are various, but similar to those of high-grade gliomas. Molecular pathology may be considered for deferential diagnosis.