yam61(1)_33.pdf 3.64 MB
Fujihara Yoshio Department of Radiology, Tottori Prefectural Central Hospital
Matsuda Eiken Department of Otorhinolaryngology, Tottori Prefectural Central Hospital
Tokuyasu Yusuke Department of Pathology, Tottori Prefectural Central Hospital
Nakamoto Shu Department of Pathology, Tottori Prefectural Central Hospital
Nakamura Kazuhiko Department of Radiology, Tottori Prefectural Central Hospital
Ogawa Toshihide Division of Radiology, Department of Pathophysiological and Therapeutic Science, School of Medicine, Tottori University Faculty of Medicine
magnetic resonance imaging
【Background】 Of all parotid gland tumors, only oncocytoma has been reported to appear isointense to the parotid gland, namely vanishing, on fat-saturated T2 and T1 postcontrast gadolinium-enhanced magnetic resonance imaging (MRI). The purpose of this study was to evaluate vanishing of parotid tumors on conventional MRI with and/or without postcontrast gadolinium-enhancement and on diffusion weighted imaging (DWI).
【Methods】 In 8 of 51 patients, ten parotid gland tumors had homogeneously enhanced lesions and were retrospectively analysed. Comparisons of signal intensity between those parotid tumors and parotid glands and evaluations of vanishing were performed on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), fat-suppressed T2WI (FS-T2WI), postcontrast gadolinium-enhanced T1WI (CE-T1WI) and fat-suppressed CET1WI (FS-CE-T1WI), DWI as well as apparent diffusion coefficient (ADC).
【Results】 Ten parotid gland tumors consisted of five Warthin tumors, two pleomorphic adenomas, two parotid carcinomas (small cell carcinoma and adenoid cystic carcinoma) and one oncocytoma. All tumors showed hypointensity on T1WI and hyperintensity on DWI. Nine of ten tumors showed vanishing on the other MR sequences. All Warthin tumors showed vanishing on FST2WI, FS-CE-T1WI and the ADC map. One oncocytoma showed vanishing on FS-T2WI and the ADC map and hyperintensity on FS-CE-T1WI. All pleomorphic adenomas showed vanishing on T2WI and CE-T1WI. One adenoid cystic carcinoma showed vanishing only on CE-T1WI.
【Conclusion】 Vanishing of parotid tumors can be observed not only on FS-T2WI and FS-CE-T1WI but also on T2WI, CE-T1WI and ADC mapping.
Tottori University Faculty of Medicine
Yonago Acta Medica
Yonago Acta Medica
Yonago Acta Medica. 2018, 61(1), 33-39