PURPOSE This study aimed to assess the magnetic resonance (MRI) features of the superior cervical ganglion (SCG) and to track changes to it induced using radiotherapy across a long-term follow-up. METHODS In total, 75 patients who underwent radiotherapy for head and neck malignancies and who were studied with MRI were recruited from two centers. MRI was performed before and after radiotherapy, with a median long-term follow-up of 4.5 years. Baseline SCG features were assessed. Changes in axial cross-sectional area, T2-normalized signal, and apparent diffusion coefficient (ADC) (the latter available in about half of the patients) were analyzed. Repeated measures analysis of variance with Bonferroni's correction was used to analyze changes in the aforementioned parameters (significance level 0.05). RESULTS Out of a potential 149 SCGs, 136 were visible at baseline MRI. A variable spatial relationship with the internal carotid artery was found. SCGs showed the "black dot" sign in almost all of the patients. ADC was higher in SCGs than in regional lymph nodes. Cross-sectional area, normalized T2, and ADC increased in the period up to 1 year after radiotherapy and then remained stable in subsequent longer-term follow-up. CONCLUSION The SCG has unusual features that allow differentiation from the regional lymph nodes. Changes in morphology and signal after radiotherapy must be taken into account by radiologists to avoid misdiagnosis as recurrent nodal disease. Changes induced using radiotherapy are stable in long-term follow-up and are thus likely attributed to other factors (such as Schwann cell hypertrophy/proliferation) rather than edema.

中文翻译：

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长期随访，上颈神经节的磁共振成像特征以及对头颈部放射治疗后的预期变化。

目的这项研究旨在评估上颈神经节（SCG）的磁共振（MRI）特征，并在长期随访中追踪使用放射疗法引起的核磁共振变化。方法总共从两个中心招募了75例行头颈部恶性肿瘤放疗并接受MRI检查的患者。放疗前后均进行了MRI检查，中位长期随访时间为4.5年。评估了基线SCG功能。分析了轴向截面积，T2归一化信号和视在扩散系数（ADC）（后者在大约一半的患者中可用）的变化。使用Bonferroni校正对方差进行重复测量分析，以分析上述参数的变化（显着性水平0.05）。结果在潜在的149个SCG中，基线MRI可见136个。发现与颈内动脉的空间关系可变。SCG在几乎所有患者中均显示“黑点”迹象。SCG中的ADC高于区域淋巴结。在放疗后长达1年的时间内，横截面积，标准化的T2和ADC增加，然后在随后的长期随访中保持稳定。结论SCG具有不寻常的特征，可与区域淋巴结区分开。放射科医生必须考虑放疗后形态和信号的变化，以避免误诊为复发性淋巴结病。使用放射疗法诱发的变化在长期随访中是稳定的，因此可能归因于其他因素（例如雪旺氏细胞肥大/增生）而不是水肿。发现与颈内动脉的空间关系可变。SCG在几乎所有患者中均显示“黑点”迹象。SCG中的ADC高于区域淋巴结。在放疗后长达1年的时间内，横截面积，标准化的T2和ADC增加，然后在随后的长期随访中保持稳定。结论SCG具有不寻常的特征，可与区域淋巴结区分开。放射科医生必须考虑放疗后形态和信号的变化，以免误诊为复发性淋巴结病。使用放射疗法诱发的变化在长期随访中是稳定的，因此可能归因于其他因素（例如雪旺氏细胞肥大/增生）而不是水肿。发现与颈内动脉的空间关系可变。SCG在几乎所有患者中均显示“黑点”迹象。SCG中的ADC高于区域淋巴结。在放疗后长达1年的时间内，横截面积，标准化的T2和ADC增加，然后在随后的长期随访中保持稳定。结论SCG具有不寻常的特征，可与区域淋巴结区分开。放射科医生必须考虑放疗后形态和信号的变化，以免误诊为复发性淋巴结病。使用放射疗法诱发的变化在长期随访中是稳定的，因此可能归因于其他因素（例如雪旺氏细胞肥大/增生）而不是水肿。