Ishibashi Mana, Fujii Shinya, Kawamoto Katsuyuki, Nishihara Keisuke, Matsusue Eiji, Kodani Kazuhiko, Kaminou Toshio, Ogawa Toshihide
Division of Radiology, Department of Pathophysiological and TherapeuticScience, Tottori University Faculty of Medicine, 36-1, Nishi-cho, Yonago, Tottori, Japan.
Acta Radiol. 2010 Dec;51(10):1103-10. doi: 10.3109/02841851.2010.519716. Epub 2010 Oct 1.
magnetic resonance (MR) imaging of parotid gland tumors has been widely reported, although few reports have evaluated the capsule of parotid gland tumors in detail.
to evaluate the diagnostic usefulness of 3.0 T MR imaging with surface coils for detection of the parotid gland tumor capsule, and to clarify the characteristics of the capsules.
seventy-eight patients with parotid gland tumors (63 benign and 15 malignant) were evaluated. Axial and coronal T2-weighted and contrast-enhanced T1-weighted images were obtained using a 3.0 T MR scanner with 70 mm surface coils. It was retrospectively assessed whether each parotid gland tumor was completely surrounded by a capsule. The capsule was classified as regular or irregular in terms of capsular thickness, and as none, mildly, or strongly enhancing in terms of contrast enhancement. Visual interpretations were compared with histopathological findings to evaluate the diagnostic ability of MR imaging to detect parotid gland tumor capsules. Statistical evaluation was conducted concerning the presence of capsules, capsular irregularity, and the difference in contrast enhancement between benign and malignant tumors, and that between pleomorphic adenomas and Warthin's tumors.
capsules completely surrounding the tumor on MR imaging yielded a sensitivity of 87.7% (50/57), specificity of 90.5% (19/21), and accuracy of 88.5% (69/78). Benign tumors had a capsule completely surrounding the tumor significantly more often than malignant tumors (P = 0.009). Concerning capsular irregularity, malignant tumors tended to have more irregular capsules than benign tumors, although there were no significant differences. The capsules of malignant tumors enhanced significantly more strongly than those of benign tumors (P = 0.018).
3.0 T MR imaging using surface coils could correctly depict parotid gland tumor capsules in most cases. Most benign and some malignant tumors had capsules completely surrounding the tumors. Malignancy should be considered in tumors with irregular and strongly enhancing capsules.
腮腺肿瘤的磁共振（MR）成像已有广泛报道，不过很少有报告对腮腺肿瘤的包膜进行详细评估。
评估使用表面线圈的3.0 T MR成像对腮腺肿瘤包膜检测的诊断价值，并阐明包膜的特征。
对78例腮腺肿瘤患者（63例良性，15例恶性）进行评估。使用配备70 mm表面线圈的3.0 T MR扫描仪获取轴位和冠状位T2加权像及对比增强T1加权像。回顾性评估每个腮腺肿瘤是否完全被包膜包绕。根据包膜厚度将包膜分为规则或不规则，根据对比增强情况分为无强化、轻度强化或明显强化。将视觉解读结果与组织病理学结果进行比较，以评估MR成像检测腮腺肿瘤包膜的诊断能力。对包膜的存在、包膜不规则性以及良性和恶性肿瘤之间、多形性腺瘤和沃辛瘤之间对比增强的差异进行统计学评估。
MR成像上肿瘤被完全包膜包绕的敏感度为87.7%（50/57），特异度为90.5%（19/21），准确度为88.5%（69/78）。良性肿瘤比恶性肿瘤更常出现肿瘤被完全包膜包绕的情况（P = 0.009）。关于包膜不规则性，恶性肿瘤的包膜往往比良性肿瘤更不规则，尽管差异无统计学意义。恶性肿瘤的包膜对比增强明显强于良性肿瘤（P = 0.018）。
使用表面线圈的3.0 T MR成像在大多数情况下能够正确描绘腮腺肿瘤的包膜。大多数良性肿瘤和一些恶性肿瘤有完全包绕肿瘤的包膜。对于包膜不规则且对比增强明显的肿瘤应考虑恶性的可能。
