The high SI observed in the cystic cavities of KCOT on T1WI reflects the presence of a large amount of keratin [8], [15] and [17]. As for DC, their cystic fluid has been reported to show low SI on T1WI, similar to general cysts [2], [15] and [22]. When DC show high SI, infection is suspected [15] and [17]. Since DC occur around the crowns of unerupted teeth and are often found near to alveolar bone, the bone margin of the lesion might be absorbed under the influence of periodontal disease, etc., in the neighboring teeth. Then, the cystic cavity of the cyst might perforate into

the oral cavity, which could be accompanied by infection or bleeding. In such cases, the cystic cavity might display high SI on T1WI. Moreover, the cyst wall is often thickened by the presence of inflammatory granulation tissue in the cyst wall. Therefore, when DC show buy Alisertib high SI on T1WI, it is necessary to observe whether the cyst wall is [thick]. Furthermore, it is necessary to observe

whether there are any signs of infection on radiographs. Although, in our study, 6 of 7 cases displayed high SI on T1WI, the cyst walls of all 3 cases that were subjected to CE-MR imaging were thin. Therefore, DC might display high SI on T1WI for reasons other than infection. MG-132 mouse We are investigating the findings of DC by increasing the number of cases. Diffusion-weighted imaging (DWI) is also worth considering as a way to examine the nature of the cyst fluid. DWI is a sequence to observe the diffusion of water molecules in the tissue. The diffusion of pure water increases, but the diffusion of solution containing proteins decreases. In addition, DWI can also evaluate uniformity of diffusion

in a tissue. Sumi et al. have evaluated about DWI of nonenhancing lesions of ameloblastomas Etofibrate and KCOTs. They have reported that the apparent diffusion coefficients (ADCs) of ameloblastomas were significantly higher than those of KCOTs, since KCOT contains desquamated keratin [10]. For the same reason, the ADCs of cystic portion in AOT may also show higher than those of cystic contents in KCOTs. Furthermore, since cystic fluid of KCOT contains exfoliated keratinous debris when DWI of that of KCOT and DC are compared, it is predicted that cystic contents of KCOT show heterogeneous DWI. We will report a method for improving the positivity rate of DC evaluations in future. All four SBC cases were subjected to DCE-MR imaging. As all 4 cases were defined as [gradual increase] in the 4th step, the positivity rate was 100%. This feature is very useful for diagnosing SBC; therefore, we recommend performing DCE-MRI in suspected SBC cases [18]. This characteristic finding of DCE-MR imaging show that the contrast medium may infiltrate into the cyst cavity. Histopathologically, the SBCs have no epithelial lining and the bony walls are covered by thin and loose-textured fibrous tissue [30] and [31].