• Imaging Science in Dentistry
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• v.43 no.2
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• pp.129-134
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• 2013

Turner syndrome (TS) is one of the most common chromosomal abnormalities, with an estimated frequency among female live births of 1/2,000-3,000. The syndrome is characterized by the partial or complete absence of one X chromosome (45,X karyotype). We reported a unique case of a 40-year-old woman with TS accompanying unexpected elongated styloid process specific to Eagle syndrome (ES) and followed up-prolactinoma. The present article is the first report to define the cone-beam computed tomographic (CBCT) features of TS accompanying ES. Patients with TS carry various risks that make treatment more complicated; thus advanced imaging techniques for proper treatment and follow-up are extremely important. In the light of CBCT examination, craniofacial abnormalities specific to TS and accompanying syndromes such as the crowding of teeth especially in the maxillary anterior region caused by maxillary narrowness, micrognatic maxilla and mandible, relative mandibular retrusion, malocclusion, open-bite, and an elongated styloid process (length of 32.7 mm) on the right side were illustrated in detail.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.535-544
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• 1995

The purpose of this study was comparision of conventional tomography with reformatted computed tomography for dental implant in locating the mandibular canal. Five dogs were used and after conventional tomographs and reformatted computed tomographs were taken, four dentist traced all films. Mandibles were sectioned with 2mm slice thickness and the sections were then radiographed(contact radiography). Each radiographic image was traced and linear measurements were made from mandibular canal to alveolar crest, buccal cortex, lingual cortex, and inferior border. Following results were acquired : 1. Reformatted computed tomographs were exacter than conventional tomography by alveolar crest to canal length of -0.6mm difference between real values and radiographs. 2. The average measurements of buccal cortex to mandibular canal width and lingual cortex to mandibular canal width of conventional tomographs were exacter than reformatted computed tomographs, but standard deviations were higher than reformatted computed tomographs. 3. Standard deviations of reformatted computed tomographs were lower than conventional tomographs at all comparing sites 4. At reformatted computed tomography 62.5％ of the measurements performed were within. : filmm of the true value, and at conventional tomography 24.1％ were. 5. Mandibular canal invisibiity was 0.8％ at reformatted computed tomography and 9.2％ at conventional tomography. Reformatted computed tomography has been shown to be more useful radiographic technique for assessment of the mandibular canal than conventional tomography.

• Journal of Biomedical Engineering Research
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• v.26 no.1
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• pp.55-63
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• 2005

A novel imaging system for High-resolution Ultrasonic Transmission Tomography (HUTT) and soft tissue differentiation methodology for the HUTT system are presented. The critical innovation of the HUTT system includes the use of sub-millimeter transducer elements for both transmitter and receiver arrays and multi-band analysis of the first-arrival pulse. The first-arrival pulse is detected and extracted from the received signal (i.e., snippet) at each azimuthal and angular location of a mechanical tomographic scanner in transmission mode. Each extracted snippet is processed to yield a multi-spectral vector of attenuation values at multiple frequency bands. These vectors form a 3-D sinogram representing a multi-spectral augmentation of the conventional 2-D sinogram. A filtered backprojection algorithm is used to reconstruct a stack of multi-spectral images for each 2-D tomographic slice that allow tissue characterization. A novel methodology for soft tissue differentiation using spectral target detection is presented. The representative 2-D and 3-D HUTT images formed at various frequency bands demonstrate the high-resolution capability of the system. It is shown that spherical objects with diameter down to 0.3㎜ can be detected. In addition, the results of soft tissue differentiation and characterization demonstrate the feasibility of quantitative soft tissue analysis for possible detection of lesions or cancerous tissue.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.209-216
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• 2021

Sjögren syndrome is a chronic autoimmune inflammatory disease characterized by lymphocytic infiltration of exocrine glands, predominantly the parotid and lacrimal glands, thereby resulting in oral and ocular dryness. It has been reported to occur most frequently in women between 40 and 50 years of age. Sjögren syndrome has an insidious onset, is slowly progressive, and presents a wide range of clinical manifestations, leading to delays or challenges in the diagnosis. Early diagnosis of this condition is essential to prevent the associated complications that affect patients' quality of life. This report presents 3 cases of Sjögren syndrome in female patients aged between 40 and 75 years who presented with complaints of persistent dry mouth and burning sensation. The cases highlight the diagnostic value of 3-dimensional cone-beam computed tomographic sialography in the detection of salivary gland pathologies at an early stage.

• Imaging Science in Dentistry
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• v.52 no.2
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• pp.187-195
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• 2022

Purpose: This study developed a convolutional neural network (CNN) model to diagnose maxillary sinusitis on panoramic radiographs(PRs) and cone-beam computed tomographic (CBCT) images and evaluated its performance. Materials and Methods: A CNN model, which is an artificial intelligence method, was utilized. The model was trained and tested by applying 5-fold cross-validation to a dataset of 148 healthy and 148 inflamed sinus images. The CNN model was implemented using the PyTorch library of the Python programming language. A receiver operating characteristic curve was plotted, and the area under the curve, accuracy, sensitivity, specificity, positive predictive value, and negative predictive values for both imaging techniques were calculated to evaluate the model. Results: The average accuracy, sensitivity, and specificity of the model in diagnosing sinusitis from PRs were 75.7%, 75.7%, and 75.7%, respectively. The accuracy, sensitivity, and specificity of the deep-learning system in diagnosing sinusitis from CBCT images were 99.7%, 100%, and 99.3%, respectively. Conclusion: The diagnostic performance of the CNN for maxillary sinusitis from PRs was moderately high, whereas it was clearly higher with CBCT images. Three-dimensional images are accepted as the "gold standard" for diagnosis; therefore, this was not an unexpected result. Based on these results, deep-learning systems could be used as an effective guide in assisting with diagnoses, especially for less experienced practitioners.

• Journal of the Optical Society of Korea
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• v.14 no.2
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• pp.77-89
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• 2010

Digital holography (DH) is a potentially disruptive new technology for many areas of imaging science, especially in microscopy and metrology. DH offers a number of significant advantages such as the ability to acquire holograms rapidly, availability of complete amplitude and phase information of the optical field, and versatility of the interferometric and image processing techniques. This article provides a review of the digital holography, with an emphasis on its applications in biomedical microscopy. The quantitative phase microscopy by DH is described including some of the special techniques such as optical phase unwrapping and holography of total internal reflection. Tomographic imaging by digital interference holography (DIH) and related methods is described, as well as its applications in ophthalmic imaging and in biometry. Holographic manipulation and monitoring of cells and cellular components is another exciting new area of research. We discuss some of the current issues, trends, and potentials.

• Imaging Science in Dentistry
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• v.41 no.1
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• pp.23-28
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• 2011

Purpose : This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. Materials and Methods : All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. Results : All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. Conclusion : The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.938-940
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• 2014

This paper discusses a coherence-gated three-dimensional imaging system based on photorefractive holography, which was applied to imaging through turbid media with a view to developing biomedical instrumentation. A rapid response photorefractive device doped with 2,4,7-trinitro-9-fluorenylidene malononitrile was used to generate the hologram grating. The estimated depth resolution was $20{\mu}m$, which corresponds to the coherence length of the light source. In this coherence imaging system, tomographic imaging of a 3-dimensional object composed of a $50{\mu}m$ thick cylindrical layer was achieved. The proposed coherence imaging system using an organic photorefractive material can be used as an optical tomography system for biological applications.

• Imaging Science in Dentistry
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• v.48 no.2
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• pp.139-145
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• 2018

Aspergilloma of the maxillary sinus is considered rare in immunocompetent patients, but a considerable increase has recently been seen in the incidence of reported cases. Dental procedures involving the antral region are thought to predispose individuals to this form of aspergillosis. Because aspergilloma shares similar clinical features with other sinus pathologies, its diagnosis may be delayed. Thus, an early diagnosis confirmed by a histopathological examination plays a crucial role in the adequate management of aspergilloma. This article provides a concise review of the reported cases of aspergilloma associated with dental procedures and reports 2 new cases of aspergilloma in middle-aged female patients, with a presentation of their cone-beam computed tomographic findings.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.540-542
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• 2004

Although artifacts in tomographic imaging can arise from a number of sources, this case presents an artifact caused by using inadequate acquisition parameters which do not match the collimator with which a camera equipped in Tc-99m ECD brain SPECT. Whenever the collimator in tomographic studies is changed, we should take care to use suitable parameters of acquisition protocol according to the collimator with which a camera is fitted. Other ways to prevent an error of this type is to use a point source.