Sano Masaki, Kaga Kimitaka, Mima Kazuo
Department of Otorhinolaryngology and Head & Neck Surgery, Graduate School of Medicine and Faculty of Medicine, University of Tokyo, and Division of Radiology, University of Tokyo Hospital, Tokyo, Japan.
Acta Otolaryngol. 2007 Aug;127(8):821-4. doi: 10.1080/00016480601075456.
While infants under the age of 1 year exhibited a high rate of abnormal intensities in the middle ear and mastoid cavities, older infants showed no abnormal intensities in these regions. From the signal intensity on T1- and T2-weighted MRI, the abnormal intensities in the middle ear cavity were considered to represent liquid effusion. Taken together with the findings of temporal bone CT, the abnormal intensities in the mastoid cavity were considered to represent bone marrow.
Histopathological studies of the temporal bone and tympanometry investigations have reported the presence of mesenchyme and liquid effusion in the middle ear cavity of infants. However, very few CT or MRI middle ear cavity findings of newborns and infants have been published, and none have included the mastoid cavity. We therefore performed an MRI study of the middle ear and mastoid cavities of infants under 2 years old (83 cases, 88 imaging series).
MRI (1.5 T) was originally performed on suspicion of brain disorders in infants aged under 2 years. All MRI slices were studied and classified on the basis of the distribution of abnormal intensities in the middle ear and mastoid cavities.
All the abnormal imaging appeared in infants under 1 year old, in particular, 74.24% (n=49) of abnormal imaging appeared in the first 20 weeks after birth.
1岁以下婴儿中耳和乳突腔内异常信号强度发生率较高，而年龄较大的婴儿在这些区域未显示异常信号强度。根据T1加权和T2加权MRI上的信号强度，中耳腔内的异常信号强度被认为代表液体渗出。结合颞骨CT的结果，乳突腔内的异常信号强度被认为代表骨髓。
颞骨组织病理学研究和鼓室图检查报告了婴儿中耳腔内存在间充质和液体渗出。然而，关于新生儿和婴儿中耳腔的CT或MRI检查结果的报道非常少，且均未包括乳突腔。因此，我们对2岁以下婴儿（83例，88个成像序列）的中耳和乳突腔进行了MRI研究。
最初对2岁以下疑似脑部疾病的婴儿进行了1.5T的MRI检查。所有MRI切片均根据中耳和乳突腔内异常信号强度的分布进行研究和分类。
所有异常成像均出现在1岁以下婴儿中，尤其是74.24%（n = 49）的异常成像出现在出生后的前20周。
