Abstract: Objective To analyze and summarize the MRI features of diffuse midline glioma with H3 K27 altered, and help us improve the rate of diagnosis.Methods The clinical and imaging data of 20 patients with diffuse midline glioma with H3 K27altered confirmed by postoperative pathology were retrospectively analyzed, and the imaging manifestations such as the location, shape and enhancement characteristics, etc.of the tumor were observed.Results Among 20 patients, 5 lesions located at thalamus, of which 3 cases involved the ventricle wall or brain lobe, 8 lesions located in brainstem, 1 case located in the third ventricle, and 3 case located in the midline and involved multiple brain lobes, 3caseslocatedinthethoracicandlumbarspinalcord.9 lesions had round-shaped and clear borders;11 lesions were irregular in shape with unclear borders.The cases showed slightly lower or equal signal onT1WI, and equal or slightly higher signal onT2WI;12 lesions had different degrees of necrosis or cystic transformation, and 5 cases showed bleeding;7cases had mild to moderate edema around the tumor, and 13 cases had no obvious edema around the tumor.5cases of hydrocephalus of varying degrees.T1WI enhancement :14 lesions showed uneven and obvious enhancement, of which 9lesionshad obvious enhancement in large or small rings, 5 cases had mild to moderate enhancement, and 1 case had no obvious enhancement.7 caseswith DWIshowed that 4 cases were slightly high signal, and 3 cases were uneven and obvious high signal.6 cases with ASL examination showedthesolidcomponent of tumor had high perfusion.4caseswith MRS showed prominent choline(CHO)and low N-acetyl aspartate(NAA) compared to the normal, and CHO/NAA ratio increased.Conclusion The appearance of diffuse midline glioma with H3 K27alteredonMRIshowed a certain specificity, which maybe helpful to improve the level of preoperative diagnosis.

Key words: Diffusemidline glioma, H3 K27altered, Arterial spin labeling, Magnetic resonance imaging

摘要： 目的 分析总结伴有H3 K27 改变的弥漫性中线胶质瘤MRI特点,以提高诊断率。方法 回顾性分析20例经术后病理证实为弥漫性中线胶质瘤伴H3K27改变患者的临床及影像资料,对肿瘤的位置形态及强化特点等影像表现进行总结分析。结果 20例中, 5例位于丘脑,其中有3例累及脑室壁或脑叶;8例位于脑干,1例位于三脑室,3例位于中线部位累及多个脑叶,3例位于胸腰段脊髓内。9例呈类圆形,边界较清楚;11例形态不规则,边界不清楚。MRI平扫T1WI为稍低或等信号,T2WI为等或稍高信号,12例存在不同程度坏死或囊变,5例存在出血。7例瘤周轻中度水肿,13例瘤周无明显水肿,5例不同程度脑积水。增强后,14例不均匀明显强化,其中9例呈大环或小环状明显强化,5例呈轻中度强化,1例无明显强化。7例行DWI扫描,其中4例为稍高信号,3例为不均匀明显高信号。6例接受ASL检查,6例肿瘤实质均表现为高灌注。4例行MRS检查,表现为NAA下降,CHO升高,CHO/NAA比值升高。结论 伴有H3K27改变的弥漫性中线胶质瘤MRI表现具有一定的特异性,有助于提高术前诊断水平。

关键词: 弥漫性中线胶质瘤, H3K27改变, 动脉自旋标记, 磁共振成像