. Programa de Pós-Graduação em Medicina e Ciências da Saúde, Faculdade de Medicina, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre (RS) Brasil.
. Department of Radiology, University of Florida, Gainesville (FL) USA.
J Bras Pneumol. 2021 Apr 2;47(2):e20200055. doi: 10.36416/1806-3756/e20200055. eCollection 2021.
Evaluation of enlarged mediastinal lymph nodes is crucial for patient management. Malignant lymphoma and sarcoidosis are often difficult to differentiate. Our objective was to determine the diagnostic accuracy of MRI for differentiating between sarcoidosis and malignant lymphoma.
This was a retrospective study involving 47 patients who underwent chest MRI and were diagnosed with one of the diseases between 2017 and 2019. T1, T2, and diffusion-weighted signal intensity were measured. Apparent diffusion coefficients (ADCs) and T2 ratios were calculated. The diagnostic performance of MRI was determined by ROC analysis.
Mean T2 ratio was significantly lower in the sarcoidosis group than in the lymphoma group (p = 0.009). The T2-ratio cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 7.1, with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 58.3%, 95.6%, 76.5%, 93.3%, and 68.7%, respectively. The mean ADC was significantly lower in the lymphoma group than in the sarcoidosis group (p = 0.002). The ADC cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 1.205, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 87.5%, 82.6%, 85.1%, 84.0% and 86.3%, respectively. No significant differences were found between the two groups regarding T1 signal intensity, T2 signal intensity, and lymph node diameter.
MRI parameters such as ADC, diffusion, and T2 ratio can be useful in the differentiation between sarcoidosis and lymphoma in the evaluation of enlarged lymph nodes.
评估纵隔淋巴结肿大对于患者管理至关重要。恶性淋巴瘤和结节病常难以鉴别。本研究旨在评估 MRI 对结节病和恶性淋巴瘤的鉴别诊断效能。
本回顾性研究纳入了 2017 年至 2019 年间经胸部 MRI 检查并确诊为上述两种疾病之一的 47 例患者。测量 T1、T2 及弥散加权信号强度，计算表观弥散系数（ADC）及 T2 比值。通过 ROC 分析评估 MRI 的诊断效能。
结节病组 T2 比值显著低于淋巴瘤组（p=0.009）。最佳区分淋巴瘤相关性和结节病相关性淋巴结肿大的 T2 比值截断值为 7.1，其敏感度、特异度、阳性预测值、阴性预测值和准确度分别为 58.3%、95.6%、76.5%、93.3%和 68.7%。淋巴瘤组 ADC 值显著低于结节病组（p=0.002）。最佳区分淋巴瘤相关性和结节病相关性淋巴结肿大的 ADC 截断值为 1.205，其敏感度、特异度、阳性预测值、阴性预测值和准确度分别为 87.5%、82.6%、85.1%、84.0%和 86.3%。两组间 T1 信号强度、T2 信号强度和淋巴结直径无显著差异。
在评估淋巴结肿大时，ADC、弥散及 T2 比值等 MRI 参数有助于结节病和淋巴瘤的鉴别。
