Wang J C, Takashima S, Takayama F, Kawakami S, Saito A, Matsushita T, Matsuba H, Kobayashi S
Department of Radiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
AJR Am J Roentgenol. 2001 Oct;177(4):929-36. doi: 10.2214/ajr.177.4.1770929.
The purpose of this study was to evaluate the accuracy of MR imaging in predicting tracheal invasion by thyroid carcinomas and to determine MR imaging criteria for diagnosing tracheal invasion.
MR imaging was performed on the normal trachea of one cadaver and 30 healthy subjects as a standard of reference. Then, MR imaging findings in 67 patients with thyroid carcinoma were reviewed and correlated with surgical and pathologic findings. A logistic regression model was used to determine which MR imaging features were significant for predicting tracheal invasion.
Twenty-three (34%) of the 67 patients had tracheal invasion. Logistic regression model analysis revealed that significant MR characteristics for determining tracheal invasion included soft-tissue signal in the tracheal cartilage (p < 0.001), intraluminal mass (p < 0.001), and degree of tumor circumference around the trachea (p = 0.001). The highest accuracy (90%) for determining tracheal invasion was achieved using a combination of findings. A case was considered positive for tracheal invasion if there was soft-tissue signal in the cartilage, an intraluminal mass, or a tumor that abutted a circumference of the trachea of 180 degrees or greater. Using these factors resulted in seven false-positive diagnoses because soft-tissue signal in the cartilage was sometimes seen in healthy trachea. Although intraluminal mass invariably reflected deep tracheal invasion, soft-tissue signal in the cartilage rarely indicated actual cartilage invasion but rather indicated tumor extension between the cartilaginous rings.
Tracheal invasion by thyroid carcinomas can be accurately diagnosed with MR imaging, and using a combination of criteria is the most accurate method of predicting this phenomenon.
本研究旨在评估磁共振成像（MR成像）预测甲状腺癌侵犯气管的准确性，并确定诊断气管侵犯的MR成像标准。
对1具尸体和30名健康受试者的正常气管进行MR成像，作为参考标准。然后，回顾67例甲状腺癌患者的MR成像表现，并与手术及病理结果进行对照。采用逻辑回归模型确定哪些MR成像特征对预测气管侵犯具有显著性意义。
67例患者中有23例（34%）发生气管侵犯。逻辑回归模型分析显示，确定气管侵犯的显著MR特征包括气管软骨内的软组织信号（p < 0.001）、管腔内肿块（p < 0.001）以及气管周围肿瘤包绕程度（p = 0.001）。综合各项表现确定气管侵犯的准确率最高（90%）。如果软骨内有软组织信号、管腔内有肿块或肿瘤包绕气管周径达180度或以上，则判定该病例气管侵犯为阳性。由于健康气管有时也可见软骨内软组织信号，使用这些因素导致7例假阳性诊断。尽管管腔内肿块总是提示气管深层侵犯，但软骨内软组织信号很少提示实际的软骨侵犯，而多提示肿瘤在软骨环之间延伸。
MR成像能够准确诊断甲状腺癌对气管的侵犯，综合应用各项标准是预测这种现象的最准确方法。
