start-ver=1.4 cd-journal=joma no-vol=44 cd-vols= no-issue=1 article-no= start-page=43 end-page=48 dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240213 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Preliminary Study of Dental Caries Detection by Deep Neural Network Applying Domain-Specific Transfer Learning en-subtitle= kn-subtitle= en-abstract= kn-abstract=Purpose The purpose of this study is to confirm whether it is possible to acquire a certain degree of diagnostic ability even with a small dataset using domain-specific transfer learning. In this study, we constructed a simulated caries detection model on panoramic tomography using transfer learning.
Methods A simulated caries model was trained and validated using 1094 trimmed intraoral images. A convolutional neural network (CNN) with three convolution and three max pooling layers was developed. We applied this caries detection model to 50 panoramic images and evaluated its diagnostic performance.
Results The diagnostic performance of the CNN model on the intraoral film was as follows: C0 84.6%; C1 90.6%; C2 88.6%. Finally, we tested 50 panoramic images with simulated caries insertion. The diagnostic performance of the CNN model on the panoramic image was as follows: C0 75.0%, C1 80.0%, C2 80.0%, and overall diagnostic accuracy was 78.0%. The diagnostic performance of the caries detection model constructed only with panoramic images was much lower than that of the intraoral film.
Conclusion Domain-specific transfer learning methods may be useful for saving datasets and training time (179/250). en-copyright= kn-copyright= en-aut-name=KawazuToshiyuki en-aut-sei=Kawazu en-aut-mei=Toshiyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TakeshitaYohei en-aut-sei=Takeshita en-aut-mei=Yohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujikuraMamiko en-aut-sei=Fujikura en-aut-mei=Mamiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OkadaShunsuke en-aut-sei=Okada en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=AsaumiJunichi en-aut-sei=Asaumi en-aut-mei=Junichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=4 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=6 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=Deep neural networks kn-keyword=Deep neural networks en-keyword=Caries detection kn-keyword=Caries detection en-keyword=Domain-Specific transfer learning kn-keyword=Domain-Specific transfer learning en-keyword=Panoramic tomography kn-keyword=Panoramic tomography END start-ver=1.4 cd-journal=joma no-vol=26 cd-vols= no-issue=3 article-no= start-page=394 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230727 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=An imaging?based diagnostic approach to vascular anomalies of the oral and maxillofacial region en-subtitle= kn-subtitle= en-abstract= kn-abstract=The accurate diagnosis of vascular anomalies (VAs) is considered a challenging endeavor. Misdiagnosis of VAs can lead clinicians in the wrong direction, such as the performance of an unnecessary biopsy or inappropriate surgical procedures, which can potentially lead to unforeseen consequences and increase the risk of patient injury. The purpose of the present study was to develop an approach for the diagnosis of VAs of the oral and maxillofacial region based on computed tomography (CT), magnetic resonance imaging (MRI) and dynamic contrast?enhanced MRI (DCE?MRI). In the present study, the CT and MR images of 87 VAs were examined, and the following imaging features were evaluated: Detectability of the lesion, the periphery of the lesion, the inner nature of the lesion, the density of the lesion on CT, the signal intensity of the lesion on MRI, the detectability of phleboliths and the shape of the lesion. A total of 29 lesions were further evaluated using the contrast index (CI) curves created from the DCE?MRI images. A diagnostic diagram, which is based on the imaging features of VAs and CI curve patterns, was subsequently extrapolated. The results obtained demonstrated that the VAs were detected more readily by MRI compared with CT, whereas the detectability of phleboliths was superior when using CT compared with MRI. VAs showed a propensity for homogeneous isodensity on CT, whereas, by contrast, they exhibited a propensity for heterogeneous hyperdensity on CE?CT. VAs also showed a propensity for homogeneous intermediate signal intensity when performing T1?weighted imaging (T1WI), heterogeneous high signal intensity when performing short tau inversion recovery MRI, and heterogeneous high signal intensity when performing fat?saturated CE?T1WI. The CI curves of VAs were found to exhibit a specific pattern: Of the 29 CI curves, 23 (79.3%) showed early weak enhancement, followed by a plateau leading up to 400?600 sec. An imaging?based diagnostic diagram was ultimately formulated. This diagram can act as an aid for radiologists when they are expecting to find a VA, and hopefully serve the purpose of simplifying the diagnostic process. Taken together, the findings of the present study indicated that DCE?MRI may be considered a useful tool for the diagnosis of VAs. en-copyright= kn-copyright= en-aut-name=Al?HammadWlla en-aut-sei=Al?Hammad en-aut-mei=Wlla kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FujikuraMamiko en-aut-sei=Fujikura en-aut-mei=Mamiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OkadaShunsuke en-aut-sei=Okada en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MunhozLuciana en-aut-sei=Munhoz en-aut-mei=Luciana kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KawazuToshiyuki en-aut-sei=Kawazu en-aut-mei=Toshiyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=TakeshitaYohei en-aut-sei=Takeshita en-aut-mei=Yohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=FujitaMariko en-aut-sei=Fujita en-aut-mei=Mariko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=AsaumiJun-Ichi en-aut-sei=Asaumi en-aut-mei=Jun-Ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Oral and Maxillofacial Radiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=3 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=4 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Stomatology, School of Dentistry, University of S?o Paulo kn-affil= affil-num=6 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=8 en-affil=Department of Oral and Maxillofacial Radiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=9 en-affil=Department of Dental Informatics, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=10 en-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital kn-affil= en-keyword=vascular anomalies kn-keyword=vascular anomalies en-keyword=magnetic resonance imaging kn-keyword=magnetic resonance imaging en-keyword=computed tomography kn-keyword=computed tomography en-keyword=dynamic contrast-enhanced magnetic resonance imaging kn-keyword=dynamic contrast-enhanced magnetic resonance imaging en-keyword=contrast index curve kn-keyword=contrast index curve END start-ver=1.4 cd-journal=joma no-vol=49 cd-vols= no-issue=1 article-no= start-page=27 end-page=34 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190525 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Fourth molar: A retrospective study and literature review of a rare clinical entity en-subtitle= kn-subtitle= en-abstract= kn-abstract=Purpose The prevalence of supernumerary teeth has been reported to be between 0.1% and 3.8%. The aim of this study was to determine the prevalence, clinical significance, and associated pathologies of fourth molars based on a retrospective study and a literature review. Materials and Methods A 5-year retrospective prevalence study was conducted at the Department of Oral Diagnosis and Dentomaxillofacial Radiology of Okayama University Hospital, Okayama, Japan. The study involved extracting data from the digital records of patients from January 1, 2013 through December 31, 2017. The sampling frame included all patients who had panoramic radiographs, cone-beam computed tomography (CT), and multislice CT images during the period under review. Results A total of 26,721 cases were reviewed and 87 fourth molars were identified. The prevalence of fourth molars in the 5-year study at Okayama was calculated as 0.32%. The mean age of patients with a fourth molar was 30.43 years, and the male-to-female ratio was 1:0.98. The vast majority of cases were in the maxilla (92%) and had normal shapes (89.7%); furthermore, 82.8% of cases were unerupted. Conclusion The prevalence of fourth molars in the study population was found to be 0.32%, and fourth molars occurred with approximately equal frequency in males and females. Fourth molars were more common in the maxilla and were predominantly unerupted and small. en-copyright= kn-copyright= en-aut-name=BamgboseBabatunde O. en-aut-sei=Bamgbose en-aut-mei=Babatunde O. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OkadaShunsuke en-aut-sei=Okada en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakeshitaYohei en-aut-sei=Takeshita en-aut-mei=Yohei kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=AbduZahrau Saleh en-aut-sei=Abdu en-aut-mei=Zahrau Saleh kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=EkuaseEdugie J. en-aut-sei=Ekuase en-aut-mei=Edugie J. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=AsaumiJun-ichi en-aut-sei=Asaumi en-aut-mei=Jun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Okayama University Hospital kn-affil= affil-num=3 en-affil=Okayama University Hospital kn-affil= affil-num=4 en-affil=Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Oral Diagnostic Sciences, Faculty of Dentistry, Bayero University Kano kn-affil= affil-num=7 en-affil=Department of Chemistry and Forensic Sciences, Savannah State University kn-affil= affil-num=8 en-affil=Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=Tooth kn-keyword=Tooth en-keyword=Supernumerary kn-keyword=Supernumerary en-keyword=Odontoma kn-keyword=Odontoma en-keyword=Odontogenic Cyst kn-keyword=Odontogenic Cyst END start-ver=1.4 cd-journal=joma no-vol=67 cd-vols= no-issue=6 article-no= start-page=359 end-page=367 dt-received= dt-revised= dt-accepted= dt-pub-year=2013 dt-pub=201312 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=In Vitro Assessment of Factors Affecting the Apparent Diffusion Coefficient of Jurkat Cells Using Bio-phantoms en-subtitle= kn-subtitle= en-abstract= kn-abstract=It is well known that many tumor tissues show lower apparent diffusion coefficient (ADC) values, and that several factors are involved in the reduction of ADC values. The aim of this study was to clarify how much each factor contributes to decreases in ADC values. We investigate the roles of cell density, extracellular space, intracellular factors, apoptosis and necrosis in ADC values using bio-phantoms. The ADC values of bio-phantoms, in which Jurkat cells were encapsulated by gellan gum, were measured by a 1.5-Tesla magnetic resonance imaging device with constant diffusion time of 30sec. Heating at 42 was used to induce apoptosis while heating at 48 was used to induce necrosis. Cell death after heating was evaluated by flow cytometric analysis and electron microscopy. The ADC values of bio-phantoms including non-heated cells decreased linearly with increases in cell density, and showed a steep decline when the distance between cells became less than 3m. The analysis of ADC values of cells after destruction of cellular structures by sonication suggested that approximately two-thirds of the ADC values of cells originate from their cellular structures. The ADC values of bio-phantoms including necrotic cells increased while those including apoptotic cells decreased. This study quantitatively clarified the role of the cellular factors and the extracellular space in determining the ADC values produced by tumor cells. The intermediate diffusion time of 30msec might be optimal to distinguish between apoptosis and necrosis. en-copyright= kn-copyright= en-aut-name=KatashimaKazunori en-aut-sei=Katashima en-aut-mei=Kazunori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KurodaMasahiro en-aut-sei=Kuroda en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=AshidaMasakazu en-aut-sei=Ashida en-aut-mei=Masakazu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SasakiTakanori en-aut-sei=Sasaki en-aut-mei=Takanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TaguchiTakehito en-aut-sei=Taguchi en-aut-mei=Takehito kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MatsuzakiHidenobu en-aut-sei=Matsuzaki en-aut-mei=Hidenobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=MurakamiJun en-aut-sei=Murakami en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=HaraMarina en-aut-sei=Hara en-aut-mei=Marina kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=KatoHirokazu en-aut-sei=Kato en-aut-mei=Hirokazu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=OhmuraYuichi en-aut-sei=Ohmura en-aut-mei=Yuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=KobayashiTomoki en-aut-sei=Kobayashi en-aut-mei=Tomoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=KanazawaSusumu en-aut-sei=Kanazawa en-aut-mei=Susumu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=HaradaSosuke en-aut-sei=Harada en-aut-mei=Sosuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=TakemotoMitsuhiro en-aut-sei=Takemoto en-aut-mei=Mitsuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=OhnoSeiichiro en-aut-sei=Ohno en-aut-mei=Seiichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= en-aut-name=MimuraSeiichi en-aut-sei=Mimura en-aut-mei=Seiichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=18 ORCID= en-aut-name=AsaumiJunichi en-aut-sei=Asaumi en-aut-mei=Junichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=19 ORCID= affil-num=1 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=2 en-affil= kn-affil=Radiological Technology, Graduate School of Health Sciences, Okayama University affil-num=3 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=4 en-affil= kn-affil=Department of Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=5 en-affil= kn-affil=Radiological Technology, Graduate School of Health Sciences, Okayama University affil-num=6 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=7 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=8 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=9 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=10 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=11 en-affil= kn-affil=Radiological Technology, Graduate School of Health Sciences, Okayama University affil-num=12 en-affil= kn-affil=Radiological Technology, Graduate School of Health Sciences, Okayama University affil-num=13 en-affil= kn-affil=Radiological Technology, Graduate School of Health Sciences, Okayama University affil-num=14 en-affil= kn-affil=Department of Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=15 en-affil= kn-affil=Department of Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=16 en-affil= kn-affil=Department of Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=17 en-affil= kn-affil=Central Division of Radiology, Okayama University Hospital affil-num=18 en-affil= kn-affil=Central Division of Radiology, Okayama University Hospital affil-num=19 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences en-keyword=ADC kn-keyword=ADC en-keyword=apoptosis kn-keyword=apoptosis en-keyword=necrosis kn-keyword=necrosis en-keyword=hyperthermia kn-keyword=hyperthermia en-keyword=cell density kn-keyword=cell density END start-ver=1.4 cd-journal=joma no-vol=47 cd-vols= no-issue=2 article-no= start-page=147 end-page=152 dt-received= dt-revised= dt-accepted= dt-pub-year=2011 dt-pub=201102 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Diagnostic value of dynamic contrast-enhanced MRI for unilocular cystic-type ameloblastomas with homogeneously bright high signal intensity on T2-weighted or STIR MR images en-subtitle= kn-subtitle= en-abstract= kn-abstract=Typical MR images of ameloblastomas on T2-weighted image (WI) or short inversion time inversion-recovery (STIR) show multiple bright high-signal-intensity loci on a high-signal-intensity background. Unilocular cystic-type ameloblastomas show homogeneously bright high signal intensity on T2WI or STIR as a water-like signal intensity. Therefore, it is difficult to distinguish unilocular cystic-type ameloblastoma from other cystic lesions such as keratocystic odontogenic tumors, radicular cysts (residual cysts) and dentigerous cysts only on the basis of MRI signal intensity. In the present study, we evaluated whether contrast-enhanced (CE)-T1WI and dynamic CE-MRI (DCE-MRI) could provide additional information for differential diagnosis in unilocular cystic-type ameloblastoma. Images from 12 cases of suspected unilocular cystic-type ameloblastoma were evaluated in the present study. Of them, 5 had areas suspected of indicating a solid component on T1WI and T2WI (or STIR). Ten had undergone additional CE-T1WI and DCE-MRI. On 5 of 10 cases of CE-T1WI, a tiny enhancement area was detected. On 6 of 10 DCE-images, a time-course enhanced area which was suspected to be a solid component was detected. CE-T1WI was helpful in the diagnosis of ameloblastoma because the tiny enhanced areas were taken to indicate possible solid components. Moreover, the rim-enhancement area on CE-T1WI could be divided into small regions of interest, and some of these showed slightly increased enhancement on DCE-MRI, which was taken to indicate a solid component and/or intramural nodule with focal invasion of ameloblastoma tissue. DCE-MRIs of the four remaining cases, which provided no clues to the diagnosis of ameloblastoma in the manner of the above descriptions, showed thicker rim enhancement than odontogenic cysts. Thus, CE-T1WI and DCE-MRI were helpful in the differential diagnosis of unilocular cystic-type ameloblastomas with homogeneously bright high signal intensity on T2WI or STIR. en-copyright= kn-copyright= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KonouchiHironobu en-aut-sei=Konouchi en-aut-mei=Hironobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MatsuzakiHidenobu en-aut-sei=Matsuzaki en-aut-mei=Hidenobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TakenobuToshihiko en-aut-sei=Takenobu en-aut-mei=Toshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=UnetsuboTeruhisa en-aut-sei=Unetsubo en-aut-mei=Teruhisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=AsaumiJun-ichi en-aut-sei=Asaumi en-aut-mei=Jun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Field Tumor Biol, Dept Oral & Maxillofacial Radiol affil-num=2 en-affil= kn-affil=Okayama Univ Hosp, Dept Oral Diag & Dentomaxillofacial Radiol affil-num=3 en-affil= kn-affil=Okayama Univ Hosp, Dept Oral Diag & Dentomaxillofacial Radiol affil-num=4 en-affil= kn-affil=Okayama Univ Hosp, Dept Oral Diag & Dentomaxillofacial Radiol affil-num=5 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Field Tumor Biol, Dept Oral & Maxillofacial Radiol affil-num=6 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Field Tumor Biol, Dept Oral & Maxillofacial Radiol affil-num=7 en-affil= kn-affil=Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Field Tumor Biol, Dept Oral & Maxillofacial Radiol en-keyword=Ameloblastoma kn-keyword=Ameloblastoma en-keyword=Unicystic kn-keyword=Unicystic en-keyword=Sold/multicystic kn-keyword=Sold/multicystic en-keyword=MRI kn-keyword=MRI en-keyword=DCE-MRI kn-keyword=DCE-MRI en-keyword=Odontogenic tumor kn-keyword=Odontogenic tumor en-keyword=Odontogenic cyst kn-keyword=Odontogenic cyst END start-ver=1.4 cd-journal=joma no-vol=26 cd-vols= no-issue=2 article-no= start-page=110 end-page=115 dt-received= dt-revised= dt-accepted= dt-pub-year=2010 dt-pub=201012 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=The utility of three-dimensional dynamic contrast-enhanced en-subtitle= kn-subtitle= en-abstract= kn-abstract=Aneurysmal bone cysts (ABCs) are classified as bone-related lesions based on the 2005 World Health Organization histological classification of odontogenic tumors. Most ABCs are diagnosed using a combination of conventional radiography, computed tomography, magnetic resonance imaging (MRI), and digital subtraction angiography. ABCs should be differentiated from true cysts or other pseudocysts because their treatment is different. Additionally, unlike other cysts, ABCs pose a hemorrhagic risk in surgery; thus, preoperative evaluation of intralesional blood flow is required. Here we report a case of a mandibular ABC in a 39-year-old woman and focus on its dynamic contrast-enhanced MRI (DCE-MRI) features. On DCE-MRI, the lesion was divided into two areas according to the enhancement pattern: the blood-pooling and blood-flow areas. The series of DCE-MR images of the blood-pooling area showed marked enhancement of the margin, but no enhancement in the inner part of the cavity. Additionally, the time-signal intensity curve (TIC) demonstrated no change in the signal intensity (SI) until approximately 15 min after gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) administration. In contrast, the series of DCE-MR images of the blood-flow area exhibited marked enhancement in the cyst cavity in the early phase. The TIC showed a rapid increase in SI in the early phase, followed by a rapid decrease until 150 s, and finally a gradual decrease until approximately 15 min after Gd-DTPA administration. Thus, in the current patient, preoperative DCE-MRI clearly delineated the vessel-rich area within the lesion. en-copyright= kn-copyright= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FujitaMariko en-aut-sei=Fujita en-aut-mei=Mariko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MatsuzakiHidenobu en-aut-sei=Matsuzaki en-aut-mei=Hidenobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KonouchiHironobu en-aut-sei=Konouchi en-aut-mei=Hironobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KataseNaoki en-aut-sei=Katase en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=NagatsukaHitoshi en-aut-sei=Nagatsuka en-aut-mei=Hitoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=AsaumiJun-ichi en-aut-sei=Asaumi en-aut-mei=Jun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil= kn-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital of Medicine and Dentistry affil-num=2 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Field of Tumor Biology, Okayama University Graduate School affil-num=3 en-affil= kn-affil=Department of Oral and Maxillofacial Radiology, Field of Tumor Biology, Okayama University Graduate School affil-num=4 en-affil= kn-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital of Medicine and Dentistry affil-num=5 en-affil= kn-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital of Medicine and Dentistry affil-num=6 en-affil= kn-affil=Department of Oral Pathology and Medicine, Field of Tumor Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=7 en-affil= kn-affil=Department of Oral Pathology and Medicine, Field of Tumor Biology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences affil-num=8 en-affil= kn-affil=Department of Oral Diagnosis and Dentomaxillofacial Radiology, Okayama University Hospital of Medicine and Dentistry en-keyword=Aneurismal bone cyst kn-keyword=Aneurismal bone cyst en-keyword=Dynamic contrastenhanced MRI kn-keyword=Dynamic contrastenhanced MRI en-keyword=MRI kn-keyword=MRI END start-ver=1.4 cd-journal=joma no-vol=51 cd-vols= no-issue=3 article-no= start-page=252 end-page=256 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20049 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Assessment of MRI and dynamic contrast-enhanced MRI in the differential diagnosis of adenomatoid odontogenic tumor en-subtitle= kn-subtitle= en-abstract= kn-abstract=

The radiographical differentiation of adenomatoid odontogenic tumor (AOT) from dentigerous cysts, calcifying odontogenic cysts, calcifying epithelial odontogenic tumors, odontogenic keratocysts, and amelobastomas is sometimes difficult. We attempted to differentiate AOT from other lesions similar to AOT in radiographic findings using MRI. The MRI features of AOT in our 3 cases included homogeneous low SI in the cystic portion and homogeneous intermediate SI in the solid portion on T1WI, homogeneous high SI in the cystic portion and intermediate to slightly high SI in the solid portion on T2WI, and enhancement of only the solid portion on CE-T1WI although non of the sequences included SI of calcifications. The contrast index curves in the 3 cases of AOT showed a gradual increase to 300 s, which signified a benign tumor. These MRI features were characteristic features of AOT and might be a basis for differentiating AOT from the above possible lesions in radiographic examinations.

en-copyright= kn-copyright= en-aut-name=AsaumiJun-ichi en-aut-sei=Asaumi en-aut-mei=Jun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KonouchiHironobu en-aut-sei=Konouchi en-aut-mei=Hironobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MatsuzakiHidenobu en-aut-sei=Matsuzaki en-aut-mei=Hidenobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=ShigeharaHiroshi en-aut-sei=Shigehara en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KishiKanji en-aut-sei=Kishi en-aut-mei=Kanji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University affil-num=6 en-affil= kn-affil=Okayama University affil-num=7 en-affil= kn-affil=Okayama University en-keyword=AOT kn-keyword=AOT en-keyword=odontogenic tumor kn-keyword=odontogenic tumor en-keyword=odontogenic cyst kn-keyword=odontogenic cyst en-keyword=MRI kn-keyword=MRI en-keyword=DCE-MRI kn-keyword=DCE-MRI END start-ver=1.4 cd-journal=joma no-vol=40 cd-vols= no-issue=6 article-no= start-page=579 end-page=584 dt-received= dt-revised= dt-accepted= dt-pub-year=2004 dt-pub=20047 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Application of dynamic contrast-enhanced MRI to differentiate malignant lymphoma from squamous cell carcinoma in the head and neck en-subtitle= kn-subtitle= en-abstract= kn-abstract=

Because malignant lymphoma, the second most common malignant tumor of the head and neck, and squamous cell carcinoma (SCC), the most common malignant tumor of the head and neck, require different treatments, it is important to be able to differentiate them. In the present study, we attempted to differentiate malignant lymphomas from SCCs using dynamic contrast-enhanced MRI (DCE-MRI). Seventeen lesions (in 8 cases) of malignant lymphoma and 30 cases of SCC were compared by DCE-MRI.

Thirteen of 17 malignant lymphomas (76.5%) showed the maximum contrast index (CI) at 90?180 s, while 26 of 30 SCCs (86.7%) showed the maximum CI at a much faster 60?105 s. There was a statistically significant difference between SCC and malignant lymphoma in the time needed reach the maximum CI (p=0.0177). There was also significant difference between SCC and malignant lymphoma in their maximum CIs (p<0.001), with the maximum CIs of 29/30 SCCs (96.7%) above 2.0, while 12/17 malignant lymphomas (70.6%) showed CIs of less than 2.0. We consider these findings to be useful for distinguishing lymphomas from SCCs.

en-copyright= kn-copyright= en-aut-name=AsaumiJun-ichi en-aut-sei=Asaumi en-aut-mei=Jun-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YanagiYoshinobu en-aut-sei=Yanagi en-aut-mei=Yoshinobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KonouchiHironobu en-aut-sei=Konouchi en-aut-mei=Hironobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MatsuzakiHidenobu en-aut-sei=Matsuzaki en-aut-mei=Hidenobu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KishiKanji en-aut-sei=Kishi en-aut-mei=Kanji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Okayama University affil-num=2 en-affil= kn-affil=Okayama University affil-num=3 en-affil= kn-affil=Okayama University affil-num=4 en-affil= kn-affil=Okayama University affil-num=5 en-affil= kn-affil=Okayama University affil-num=6 en-affil= kn-affil=Okayama University en-keyword=DCE-MRI kn-keyword=DCE-MRI en-keyword=Head and neck kn-keyword=Head and neck en-keyword=Lymphoma kn-keyword=Lymphoma en-keyword=Squamous cell carcinoma kn-keyword=Squamous cell carcinoma en-keyword=Contrast index curve kn-keyword=Contrast index curve END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2008 dt-pub=20080325 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=tBᇂdynamic contrast-enhanced MRI ɂ] kn-title=Diagnostic value of dynamic contrast-enhanced MRI in the salivary gland tumors en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=HisatomiMiki en-aut-sei=Hisatomi en-aut-mei=Miki kn-aut-name=vxI kn-aut-sei=vx kn-aut-mei=I aut-affil-num=1 ORCID= affil-num=1 en-affil= kn-affil=Rw END