• 한국임상수의학회지
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• 제24권4호
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• pp.667-672
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• 2007

This report describes the use of conventional computed tomography(CT) for the diagnosis of head trauma in three canine patients. According to physical and neurologic examinations, survey radiography and computed tomography, these patients were diagnosed as traumatic brain injury. Especially, CT is the imaging modality of first choice for head trauma patients. It provides rapid acquisition of images, superior bone detail, and better visualization of acute hemorrhage than magnetic resonance imaging. It is also less expensive and more readily available. Pre-contrast computed tomography was used to image the head. Then, post-contrast CT was performed using the same technique. The Modified Glasgow Coma Scale(MGCS) score was used to predict their probability of survival rate after head trauma in these dogs. Computed tomogram showed fluid filled tympanic bulla, fracture of the left temporal bone and cerebral parenchymal hemorrhage with post contrast ring enhancement. However, in one case, computed tomographic examination didn't delineate cerebellar parenchymal hemorrhage, which was found at postmortem examination. Treatments for patients placed in intensive care were focused to maintain cerebral perfusion pressure and to normalize intracranial pressure. In these cases, diagnostic computed tomography was a useful procedure. It revealed accurate location of the hemorrhage lesion.

• 대한한의학회지
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• 제17권1호
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• pp.171-189
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• 1996

Background and Purpose: The greater part of patients to visit Hospital of Oriental Medicine suffer from cerebrovascular accident(CVA). There is transcranial Doppler(TCD) in the diagnostic method to confirm cerebrovascular accident(CVA). Transcranial Doppler(TCD) is an accurate method of monitoring the blood flow velocities of the cerebral vessels and have been generally used to prevent symptomatic vasospasm and confirm cerebral infarction. So we studied, in the crebrovascular accident(CVA), to estimate whether transcranial Doppler(TCD) is useful to. Methods: Using transcranial doppler(Multigon Model 500M Transcranial Doppler System), we measured the mean and peak velocity and the direction of blood flow in 10 cerebrovascular accident(CVA)'s subjects who had been examined by Computed Tomography(CT) or Magnetic Resonance Imaging (MRI). Results : As an anticipation, in cerebrovascular accident(CVA)'s subject with Cb-infarction, the mean and peak velocity of blood flow fell down remarkably and the direction of blood flow was change or irritable. But didn't find out any signal in lacunar infarction. Also, in case with spontaneous hemorrhage, the velocity and direction of blood flow was change but this signal was short of diagnosis for Cb-hemorrhage. Besides, we found signals about embolism, stenosis, thrombosis and occlusion in cerebrovascular accident(CVA)'s subjects. Conclusion: In Cb-infarction, the result of TCD was equal to diagnosis with Computed Tomography(CT) or Magnetic Resonance Imaging (MRI). But about lacunar infarction or spontaneous hemorrhage, signals of TCD couldn't be found out or was insufficient more than Computed Tomography(CT) or Magnetic Resonance Imaging(MRI). In cerebrovascular accident(CVA)'s subject with embolism, stenosis, thrombosis or occlusion, signals of TCD were found out more than Computed Tomography(CT) or Magnetic Resonance Imaging(MRI). Therefore transcranial doppler(TCD) is necessary method which makes a diagnosis of cerebrovascular accident(CVA), with Computed Tomography(CT) or Magnetic Resonance Imaging(MRI).

• Journal of Trauma and Injury
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• 제28권3호
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• pp.195-197
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• 2015

Artifacts can seriously degrade the quality of computed tomography (CT) images, sometimes to the point of making them diagnostically unusable. Here, we report an unusual CT artifact that could have resulted in the misdiagnosis of a hyperdense hemorrhagic lesion in a 55-year-old man. The author recommend that when hemorrhagic lesion in posterior fossa is suggested on CT, the physician should carefully consider all patient-related clinical data prior to considering surgical intervention or a biopsy. Cranial magnetic resonance imaging (MRI) can help in preventing the misdiagnosis as hemorrhage of CT scan.

• Imaging Science in Dentistry
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• 제45권1호
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• pp.61-65
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• 2015

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.49-56
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• 2008

Purpose: Diagnostic estimation of destruction and formation of bone has the typical limit according to capacity of x-ray generator and image detector. So the aim of this study was to find out how much it can reproduce the shape and the density of bone in the case of using recently developed dental type of cone beam computed tomography, and which image is applied by new detector and mathematic calculation. Materials and Methods: Cone beam computed tomography (PSR 9000N, Asahi Roentgen Ind. Co., Ltd., Japan) and soft x-ray radiography were executed on dry mandible that was already decalcified during 5 hours, 10 hours, 15 hours, 20 hours, and 25 hours. Estimating and comparing of those came to the following results. Results: The change of inferior border of mandible and anterior border of ramus in the region of cortical bone was observed between first 5 and 10 hours of decalcification. The reproduction of shape and density in the region of cortical bone and cancellous bone can be hardly observed at cone beam computed tomography compared with soft x-ray radiography. The difference of decrease of bone density according to hours of decalcification increase wasn't reproduced at cone beam computed tomography compared with soft x-ray radiography. Conclusion: CBCT images revealed higher spatial resolution. However, contrast resolution in region of low contrast sensitivity is the inferiority of images' property.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.31-39
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• 2018

Purpose: This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from cone-beam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. Materials and Methods: A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values(MGVs) of each cylinder were calculated in each imaging protocol. Results: In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes(P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. Conclusion: The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.291-298
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• 2020

Purpose: The detection and exact localization of penetrating foreign bodies are crucial for the appropriate management of patients with dentoalveolar trauma. This study compared the efficacy of cone-beam computed tomography (CBCT) and spiral computed tomography (CT) scans for the detection of different foreign bodies composed of 5 frequently encountered materials in 2 sizes. The effect of the location of the foreign bodies on their visibility was also analyzed. Materials and Methods: In this in vitro study, metal, tooth, stone, glass, and plastic particles measuring 1×1×1 mm and 2×2×2 mm were prepared. They were implanted in a sheep's head in the tongue muscle, nasal cavity, and at the interface of the mandibular cortex and soft tissue. CBCT and spiral CT scans were taken and the visibility of foreign bodies was scored by 4 skilled maxillofacial radiologists who were blinded to the location and number of foreign bodies. Results: CT and CBCT were equally accurate in visualizing metal, stone, and tooth particles of both sizes. However, CBCT was better for detecting glass particles in the periosteum. Although both imaging modalities visualized plastic particles poorly, CT was slightly better for detecting plastic particles, especially the smaller ones. Conclusion: Considering the lower patient radiation dose and cost, CBCT can be used with almost equal accuracy as CT for detecting foreign bodies of different compositions and sizes in multiple maxillofacial regions. However, CT performed better for detecting plastic particles.

• Journal of Magnetics
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• 제20권3호
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• pp.302-307
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• 2015

The purpose of the study was to identify how isotope and magnetic resonance imaging (MRI) contrast media impact on noise to computed tomography (CT) examination. For the study, divide the phantoms to two groups: 1) saline, saline + different kinds of contrast agent without $^{99m}Tc$ administration; 2) $^{99m}Tc$ administration: saline, saline + different kinds of contrast agent with $^{99m}Tc$ administration. CT contrast agent was used for Iopamidol$^{(R)}$ and Dotarem. And MRI contrast agent was used for Primovist$^{(R)}$ and Gadovist$^{(R)}$. To obtain an image, we used CT scanner. With an obtained image, we set the $1cm^2$ region of interest in the middle of bottle to measure the noise and CT number. As a result, there was no difference in CT number before and after inserting $^{99m}Tc$ into all contrast media including Normal Saline. However, when it comes to Noise, there was a difference before and after inserting $^{99m}Tc$ into every contrast media except MRI contrast media such as Primovist$^{(R)}$ and Gadovist$^{(R)}$.

• 대한치과의사협회지
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• 제53권12호
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• pp.967-974
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• 2015

Purpose: This study was performed to investigate the characteristics of mandibular incisive canal (MIC) in Korean population. Materials and methods: A total of 97 subjects (60 males and 37 females) who underwent cone-beam computed tomography were included in the study. The anatomic features of MIC was assessed according to gender. Length, diameter and distance to inferior, lingual and buccal border were measured at the origin and the terminal. Also the distribution of MIC at each tooth position was evaluated. Results: Of 97 patients included, 75(77.3%) presented bilateral MIC and 13(13.4%) presented unilateral MIC. Of 194 hamimandibles, MIC was detected in 102(85%) sites in male and 61(82.4%) sites in female. Gender and side showed no statistically significant differences in detectability. The length, diameter and distance to adjacent structures were bigger in male than in female except the distance to lingual border. MIC travelled anteriorly in a slightly downward and lingual direction and usually terminated between the first premolar and the canine. On cross-sectional view, MIC showed individually scattered distribution both buccolingually and superoinferiorly. Conclusion: MIC is well detected with cone-beam computed tomography. Considered that the length and the location of MIC has large variations between individuals, its localization using cone-beam CT is highly recommended before performing surgical procedures such as implant placement and bone harvesting.

• Journal of Oral Medicine and Pain
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• 제47권3호
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• pp.156-160
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• 2022

Temporomandibular joint (TMJ) ankylosis is a condition in which condylar movement is restricted because of fibrous or bony union between the mandibular condyle and temporal bone. TMJ ankylosis is most often caused by trauma, followed by systemic or local infection, and secondary to unknown causes. Diagnostic imaging plays a vital role in diagnosing TMJ ankylosis and establishing a treatment plan. Computed tomography (CT) or cone beam computed tomography (CBCT) is currently the imaging technique of choice to accurately demonstrate preoperative ankylosing masses and other surgically important findings, such as the shape of the mandibular condyle and the pathological changes in the joint. The osseous changes in the mandibular condyle are easily identified in the coronal and sagittal sections of CT or CBCT images. This report describes the case of a middle-aged woman who developed TMJ ankylosis of the left TMJ while undergoing repeated treatment for TMJ disease. We report the findings observed on radiographic and CBCT images through continuous observation.