56 research outputs found

    Palatal bone defect mimicking a chronic periapical lesion: a case report emphasizing the importance of the use of a three-dimensional radiographic examination

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    Lesão periapical crônica é uma das patologias ósseas mais comuns em dentes humanos, e é detectada primariamente por radiografia simples, como a panorâmica ou periapical. Radiografias simples são amplamente utilizadas em odontologia; no entanto, elas são limitadas por questões inerentes à técnica em si, tais como a sobreposição de estruturas anatômicas e a falta de informação sobre a extensão da lesão. Portanto, métodos radiográficos tridimensionais, como a tomografia computadorizada de feixe cônico, são valiosos para avaliar com precisão as lesões periapicais. Dessa forma, este relato clínico descreve um caso em que as características radiográficas de osso levaram a um diagnóstico primário de lesão periapical crônica nos incisivos superiores, no entanto, era um defeito palatino. A radiolucência resultante foi causada pelo defeito palatino sobreposto ao osso maxilar, imitando, assim, uma lesão periapical. Além disso, no mesmo caso, demonstramos uma lesão periapical crônica verdadeira em outra área. Essa lesão apareceu como uma radiolucência sutil na radiografia periapical, mas foi maior que o esperado quando avaliada por tomografia computadorizada de feixe cônico.Chronic periapical lesion is among the most usual bone pathology observed in human teeth, and it is often first detected by plain radiographs, such as panoramic or periapical radiography. Plain radiographs are widely used in dentistry; however, they have limitations inherent to the technique itself, such as anatomic structures overlapping and lack of information on the extension of the lesion. Therefore, three-dimensional radiographic methods, such as cone beam computed tomography are valuable to accurately assess periapical lesions. Thus, this clinical report describes a case in which the bone radiographic features led to a primary diagnosis of chronic periapical lesion in superior incisors, however, it was a defect in the palatal bone. The resulting radiolucency created by the palatal bone defect overlapped the maxillary bone, mimicking a periapical lesion. Additionally, in the same case, we demonstrate a true chronic periapical lesion in another area that presented as a subtle radiolucency in periapical radiography, however, it was larger than expected when evaluated in Cone Beam Computed Tomography

    Stafne bone defects radiographic features in panoramic radiographs : assessment of 91 cases

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    To evaluate 91 cases of Stafne bone defect (SBD) in panoramic radiographs (PR) to determine the prevalence of different SBD variants, considering age, gender, and side. Additionally, to assess the most frequent imaging features of SBD. Participant data were collected from 91 SBD cases with PR imaging. First, SBDs were classified according to their location, as anterior, posterior, or ramus variant. SBD imaging features were classified according to radiographic imaging findings, assessing margins, degree of internal radiolucency, shape, topographic relationship between the defect and mandibular border, location of the defect according to mandibular teeth, and locularity. The topographic relationship between the SBD and the mandibular canal was described for the inferior variant only. Mean sizes were also described. A total of 92 SBD cases were evaluated from 91 radiographs. One case presented multiple defects. Mean patient age was 60.80 years. Men were more affected than women. The most frequent SBD variant was the posterior variant, and the least frequent was the ramus variant. The most observed radiographic features were thick sclerotic bone margin in the entire contour of the defect, partially radiolucent internal content, oval shape, continuity with mandible base without discontinuity of mandible border, third molar region location, and unilocular shape. With the posterior variant only, the most common topographic relationship between the defect and the upper wall of the mandibular canal was the defect located below the upper wall and continuous with the inferior wall of the mandibular canal. The knowledge of common SBD radiographic imaging features in PR can help dental practitioners with the differential diagnosis of SBD

    Relationship between stylohyoid ligament calcification and systemic osteoporosis by CBCT and panoramic radiography

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    The purpose of this study was to use panoramic radiography and cone beam computed tomography images to investigate (1) the accuracy of these methods concerning osteopenia and osteoporosis diagnosis, and (2) the correlation between presence of stylohyoid ligament calcification and osteopenia and osteoporosis. A hundred seventy-one images from digital archive were enrolled in this study. All panoramic radiography and cone beam computed tomography images were obtained using the Veraviewepocs 3D system and observed at i-VIEW-3DX software. For osteopenia and osteoporosis diagnosis, the mandibular cortex was assessed.  Presence of stylohyoid ligament calcification was also assessed and mineralization in all parts of the stylohyoid complex was considered. All recorded data were referred to statistical analysis and the significance level was set at 5%. There is an agreement between the imaging modalities for osteopenia and osteoporosis diagnosis, since the rate of disagreement is 21.6%. The results confirmed the osteoporosis diagnosis in elderly women and the correlation between osteopenia and osteoporosis diagnosis and the presence of stylohyoid ligament calcification (p 0.06). The present study suggests that (1) panoramic radiography and computed tomography images are accurate enough for osteopenia and osteoporosis diagnosis with low disagreement rate between methods and (2) there is a significant correlation between presence of stylohyoid ligament calcification and osteopenia and osteoporosis diagnosis in elderly women

    Evaluation of basilar expansion and internal septa of human sphenoidal sinus using cone beam computed tomography

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    The objective of this study was to assess the types and frequencies of basilar expansion of the sphenoidal sinus and internal septa by using cone beam computed tomography. Archived images from 300 adult subjects of both genders were retrieved. A descriptive analysis relating age and gender to basilar expansion of the sphenoidal sinus and internal septa types and frequencies was performed. The associations between basilar expansion of the sphenoidal sinus, internal septa and gender for each age group were assessed using the chi-square test or Fisher’s exact test. Among all the images evaluated, 69% showed basilar expansion of the sphenoidal sinus, of which 81% were considered critical. Internal septa were observed in 60% of the images. There was no relationship between the presence of basilar expansion of the sphenoidal sinus and gender and age. Internal septa were independent of gender; however, of the subjects older than age 40, 36% had only a main septum, 6% had accessory septa, and 18% had both types of septa. Cone beam computed tomography is an accurate method that should be considered for the evaluation of this anatomic segment in order to avoid unnecessary exposure to radiation.O objetivo deste estudo foi avaliar os tipos e as frequências de expansão basilar do seio esfenoidal e septos internos utilizando tomografia computadorizada de feixe cônico. Imagens arquivadas de 300 indivíduos adultos de ambos os gêneros foram recuperadas. Foi realizada uma análise descritiva relacionando idade e gênero à expansão basilar do seio esfenoidal e a tipos de septos internos e frequências. As associações entre expansão basilar do seio esfenoidal, septos internos e gênero para cada grupo de idade foram avaliadas por meio do teste do qui-quadrado ou teste exato de Fisher. Entre todas as imagens avaliadas, 69% apresentaram expansão basilar do seio esfenoidal, das quais 81% foram consideradas críticas. Septos internos foram observados em 60% das imagens. Não houve relação entre presença de expansão basilar do seio esfenoidal, gênero e idade. Septos internos apresentaram-se independentes do gênero; no entanto, dentre os indivíduos com mais de 40 anos de idade, 36% tinham apenas um septo principal, 6% tinham septos acessórios, e 18% tinham ambos os tipos de septos. A tomografia computadorizada é um método preciso que deve ser considerado para a avaliação desse segmento anatômico a fi m de evitar a exposição desnecessária à radiação

    Phase I Trial of Escalating-dose Cisplatin with 5-fluorouracil and Concurrent Radiotherapy in Chinese Patients with Esophageal Cancer

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    We defined the maximum-tolerated dose (MTD) of chemoradiotherapy (cisplatin (CDDP) with 5-fluorouracil (5-FU) and concurrent chemoradiotherapy) for Chinese patients with esophageal cancer. Twenty-one previously untreated patients with primary esophageal cancer were entered into this study. Escalating doses of CDDP with 5-FU were administered in a modified Fibonacci sequence, with concurrent conventional fractionation radiotherapy (CFR) of 60 Gy or 50 Gy. The starting doses were CDDP 37.5 mg/m2 on day 1, and 5-FU 500 mg/m2 on days 1-5, respectively. The regimen was repeated 4 times every 28 days. If no dose-limiting toxicity (DLT) was observed, the next dose level was applied. The procedures were repeated until DLT appeared. The MTD was declared to be 1 dose level below the level at which DLT appeared. DLT was grade 3 radiation-induced esophagitis at a dose level of CDDP 60 mg/m2 with 5-FU 700 mg/m2 and concurrent 60 Gy CFR. MTD was defined as CDDP 52.5 mg/m2 with 5-FU 700 mg/m2 and concurrent 50 Gy CFR. The MTD of CDDP with 5-FU and in concurrent chemoradiotherapy for Chinese patients with esophageal cancer is CDDP 52.5 mg/m2 on day 1 and 5FU 700 mg/m2 on days 1-5, repeated 4 times every 28 days, and concurrent 50 Gy CFR. Further evaluation of this regimen in a prospective phase II trial is ongoing.</p

    In Vitro Assessment of Factors Affecting the Apparent Diffusion Coefficient of Ramos Cells Using Bio-phantoms

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    The roles of cell density, extracellular space, intracellular factors, and apoptosis induced by the molecularly targeted drug rituximab on the apparent diffusion coefficient (ADC) values were investigated using bio-phantoms. In these bio-phantoms, Ramos cells (a human Burkittセs lymphoma cell line) were encapsulated in gellan gum. The ADC values decreased linearly with the increase in cell density, and declined steeply when the extracellular space became less than 4 μm. The analysis of ADC values after destruction of the cellular membrane by sonication indicated that approximately 65% of the ADC values of normal cells originate from the cell structures made of membranes and that the remaining 35% originate from intracellular components. Microparticles, defined as particles smaller than the normal cells, increased in number after rituximab treatments, migrated to the extracellular space and significantly decreased the ADC values of bio-phantoms during apoptosis. An in vitro study using bio-phantoms was conducted to quantitatively clarify the roles of cellular factors and of extracellular space in determining the ADC values yielded by tumor cells and the mechanism by which apoptosis changes those values

    The Usefulness of Readout-Segmented Echo-Planar Imaging (RESOLVE) for Bio-phantom Imaging Using 3-Tesla Clinical MRI

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    Readout-segmented echo-planar imaging (RESOLVE) is a multi-shot echo-planar imaging (EPI) modality with k-space segmented in the readout direction. We investigated whether RESOLVE decreases the distortion and artifact in the phase direction and increases the signal-to-noise ratio (SNR) in phantoms image taken with 3-tesla (3T) MRI versus conventional EPI. We used a physiological saline phantom and subtraction mapping and observed that RESOLVE’s SNR was higher than EPI’s. Using RESOLVE, the combination of a special-purpose coil and a large-loop coil had a higher SNR compared to using only a head/neck coil. RESOLVE’s image distortioas less than EPI’s. We used a 120 mM polyethylene glycol phantom to examine the phase direction artifact.vThe range where the artifact appeared in the apparent diffusion coefficient (ADC) image was shorter with RESOLVE compared to EPI. We used RESOLVE to take images of a Jurkat cell bio-phantom: the cell-region ADC was 856×10−6mm2/sec and the surrounding physiological saline-region ADC was 2,951×10−6mm2/sec. The combination of RESOLVE and the 3T clinical MRI device reduced image distortion and improved SNR and the identification of accurate ADC values due to the phase direction artifact reduction. This combination is useful for obtaining accurate ADC values of bio-phantoms

    Evaluation of Setup Errors at the Skin Surface Position for Whole Breast Radiotherapy of Breast Cancer Patients

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    We used image-processing software to analyze the setup errors at the skin surface position of breast cancer patients (n=66) who underwent post-operative whole breast irradiation at our hospital in 2014-2015. The sixty-six digital reconstructed radiographs (DRR) were created at the treatment planning for each patient. The lineacgraphies (n=377) were taken after the patients’ setup during radiotherapy. The lineacgraphies and DRR were superimposed at the skin surface position for each patient with the image-processing software. We measured the deviations of the isocenters for the nipple-lung (X) direction and craniocaudal (Y) direction and the deviation of the rotation angle of the XY axes between the lineacgraphy and DRR on the superimposed images. The systematic error (μ, Σ) and random error (σ) were calculated from the X and Y deviations and rotation angle deviation. The μ of X, Y, and rotation angle were 0.01 mm, −1.2 mm, and 0.05°, respectively. The Σ of X, Y, and rotation angle were 1.8 mm, 1.5 mm, and 0.9°, respectively. The σ of X, Y, and rotation angle were 2.0 mm, 1.5 mm, and 1.0°, respectively. Our analyses thus revealed that evaluations using image-processing software at the skin surface position in routine breast radiotherapy result in sufficiently small setup errors

    Organizing Active Learning Models in Science Classes (2)

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    The purpose of this study is to organize active learning models in science classes. Through classroom practice from elementary school to upper secondary school, we observed the followings: 1) the "reciprocal of internalization and externalization," which means collaborative and cooperative learning, is the key to active learning in science lessons; 2) by creating a "subject skeleton," teachers can gain clarity regarding the promotion of deep learning and organize active learning models in science classes

    Relative biological effectiveness (RBE) and potential leathal damage repair (PLDR) of heavy-ion beam

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    150KV X線,中性子線及び炭素(LET13, 20, 50, 90, 140, 150, 153, 200keV/μm)を照射したマウスNIH3T3細胞の生存率曲線のLD(10)から(60)Coγ線に対する生物学的効果比(RBE)を求めた。RBEは150KV X線では1.26,中性子線では2.44,炭素線(LET13, 20, 50, 90, 140, 150, 153, 200keV/μm)ではそれぞれ1.41, 1.47, 2.22, 2.61, 1.61, 2.05, 1.57であった。LETとRBEの関係では100keV/μm付近にピークを認めた。150KVX線のLETは13keV/μm,中性子線のLETは70keVμmに相当した。(60)Co γ線の潜在性致死損傷からの回復(PLDR)は大きかった。炭素線(13keV/μm)照射でもPLDRが観察されるがLETが大きくなるとPLDRは減少したが,LET90keV/μmの炭素線でもPLDRが認められた。照射時の細胞状態の検討では増殖期の細胞の感受性は定常期細胞に比し僅かに高かった。Relative biological effectiveness (RBE) and repair of potential lethal damage (PLDR) of NIH3T3 cells against heavy-ion radiation were studied. RBE of 150 KV X-rays and neutron estimated from LD(10) dose of dose response survival curves compared to (60)Co γ-ray were 1.26 and 2.44, respectively. RBE of 13, 20, 50, 90, 140, 150, 153, 200 keV/μm of LET of carbon beam were 1.41, 1.47, 2.22, 2.61, 2.61, 1.61, 2.05 and 1.57, respectively. Potential lethal damage repair (PLDR) after exposure to carbon beam was observed. The magnitude of PLDR of (60)Co γ-ray was the biggest. As for the carbon beam of LET of 13 keV/μm as well, PLDR were observed. PLDR decreased when LET of carbon beam grew big
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