• Imaging Science in Dentistry
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• 제32권1호
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• pp.19-25
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• 2002

Purpose: To evaluate the degree of accuracy of DentaScan reformatted images of the maxillary sinus and periapical, periodontal lesions and to clarify the usefulness of the reconstructed 3-dimensional images to the dental clinical aspects. Materials and Methods: 33 sides of maxillae of the hemi-sectioned Korean heads were used in this study. Periapical radiographs, computed tomography and DentaScan reformatted cross-sectional images were taken for the radiographic evaluation of the peiapical and peiodontal lesions of the maxillary teeth and inferior wall of maxillary sinus. Results : Compared the degree of accuracy and findings of dental and periapical pathoses on the intraoral radiographs and DentaScan reformatted images with the cross-sectioned specimens, the DentaScan reformatted cross-sectional images were more accurate and more effective than the intraoral radiography with a viewpoint of the detection of dental and periapical pathoses. Conclusion: Comparing the lesions of specimens with intraoral radiographies and DentaScan reformatted images, the dental and periodontal pathoses and topographical structures were more clearly observed in the DentaScan reformatted images, providing the possibility of more applications of reformatted images to clinical dentistry.

• Imaging Science in Dentistry
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• 제41권2호
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• pp.71-78
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• 2011

Purpose : This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. Materials and Methods : Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. Results : The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. Conclusion : The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm.

• Imaging Science in Dentistry
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• 제47권1호
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• pp.39-44
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• 2017

Purpose: Insufficient knowledge of the anatomy of the maxillary sinuses prior to sinus graft surgery may lead to perioperative or postoperative complications. This study sought to characterize the position of the posterior superior alveolar artery (PSAA) within the maxillary sinuses using cone-beam computed tomography (CBCT). Materials and Methods: A total of 300 patients with edentulous posterior maxillae, including 138 females and 162 males with an age range of 33-86 years, who presented to a radiology clinic between 2013 and 2015 were enrolled in this retrospective cross-sectional study. The distance from the inferior border of the PSAA to the alveolar crest according to the residual ridge classification by Lekholm and Zarb, the distance from the PSAA to the nasal septum and zygomatic arch, and the diameter and position of the PSAA were all assessed on patients' CBCT scans. The data were analyzed using the Mann-Whitney test and the t-test. Results: The PSAA was detected on the CBCT scans of 87% of the patients; it was located beneath the sinus membrane in 47% of cases and was intraosseous in 47% of cases. The diameter of the artery was between 1 and 2 mm in most patients (72%). The mean diameter of the artery was $1.29{\pm}0.39mm$, and the mean distances from the PSAA to the zygomatic arch, nasal septum, and alveolar crest were $22.59{\pm}4.89mm$, $26.51{\pm}3.52mm$, and $16.7{\pm}3.96mm$, respectively. Conclusion: The likelihood of detecting the PSAA on CBCT scans is high; its location is intraosseous or beneath the sinus membrane in most patients. Determining the exact location of the PSAA on CBCT scans preoperatively can help prevent it from being damaged during surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권1호
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• pp.41-48
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• 2020

Objectives: One of the most common complications of bilateral sagittal split ramus osteotomy (BSSRO) is neurosensory impairment of the inferior alveolar nerve (IAN). Accurate preoperative determination of the position of the IAN canal within the mandible using cone-beam computed tomography (CBCT) is recommended to prevent IAN dysfunction during BSSRO and facilitate neurosensory improvement after BSSRO. Materials and Methods: This randomized clinical trial consisted of 86 surgical sites in 43 patients (30 females and 13 males), including 21 cases (42 sides) and 22 controls (44 sides). Panoramic and lateral cephalographs were obtained from all patients. In the experimental group, CBCT was also performed from both sides of the ramus and mandibular body. Neurosensory function of the IAN was subjectively assessed using a 5-point scale preoperatively and 7 days, 1 month, 3 months, 6 months, and 12 months post-surgery. Data were analyzed using Fisher's test, Spearman's test, t-test, linear mixed-model regression, and repeated-measures ANCOVA (α=0.05, 0.01). Results: Mean sensory scores in the control group were 1.57, 2.61, 3.34, 3.73, and 4.20 over one year and were 1.69, 3.00, 3.60, 4.19, and 4.48 in the CBCT group. Significant effects were detected for CBCT intervention (P=0.002) and jaw side (P=0.003) but not for age (P=0.617) or displacement extent (P=0.122). Conclusion: Preoperative use of CBCT may help surgeons to practice more conservative surgery. Neurosensory deficits might heal faster on the right side.

• Nuclear Medicine and Molecular Imaging
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• 제41권3호
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• pp.252-254
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• 2007

Image fusion is fast catching attention as Wagner pointed out in his 2006 version of the recent progress and development presented at the annual meeting of Society of Nuclear Medicine. Prototypical fusion of bone scan and radiograph was already attempted at in 1961 when Fleming et al. published an article on strontium-85 bone scan. They simply superimposed dot scan on radiograph enabling simultaneous assessment of altered bone metabolism and local bone anatomy. Indeed the parallel reading of images of bone scan and radiography, CT, MRI or ultrasonography has been practiced in nuclear medicine long since. It is fortunate that recent development of computer science and technology along with the availability of refined CT and SPECT machines has permitted us to open a new avenue to digitally produce precise fusion image so that they can readily be read, exchanged and disseminated using internet. Ten years ago fusion was performed using Bresstrahlung SPECT/CT and it is now achievable by PET/CT and SPECT/CT software and SPECT/CT hardware. The merit of image fusion is its feasibility of reliable assessment of morphological and metabolic change. It is now applicable not only to stationary organs such as brain and skeleton but also to moving organs such as the heart, lung and stomach. Recently, we could create useful fusion image of cardiac SPECT and 64-channel CT angiograph. The former provided myocardial metabolic profile and the latter vascular narrowing in two patients with coronary artery stenosis and myocardial ischemia. Arterial stenosis was severe in Case 1 and mild in Case 2.

• 한국임상수의학회지
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• 제33권3호
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• pp.168-171
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• 2016

Signalment: An 8-month-old female Alaskan malamute was presented for progressive cluster seizure disorder. Results: There were no abnormalities on neurological examination, survey radiographs, or blood analysis. Magnetic resonance (MR) imaging and computed tomography revealed extension of the olfactory bulb and frontal lobe into the nasal cavity. They also confirmed abnormal anatomy of the nasal turbinates within the rostral part of the nasal cavity and the absence of a cribriform plate. On T2-weighted and fluid-attenuated inversion recovery images, the herniated brain showed heterogeneous and hyperintense signals consistent with intraparenchymal edema. Transverse MR images showed brain herniation into the right frontal cavity and an asymmetrical lateral ventricle because of a left midline shift. On contrast-enhanced MR images, the protruding brain parenchyma was mildly enhanced. Ethmoidal encephalocele was suspected as the final diagnosis. Despite symptomatic treatment, the dog continued to exhibit seizures and was euthanized. Clinical relevance: Ethmoidal encephalocele is a rare disease in dogs. However, it could be considered as a cause of seizure in young dogs.

• Journal of Korean Neurosurgical Society
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• 제49권6호
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• pp.351-354
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• 2011

Objective : This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. Methods : Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement Results : Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. Conclusion : C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.487-491
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• 2018

The purpose of this study was to analyze questionnaires of 161 college students attending radiology departments in order to investigate the actual condition of internet use of radiology students. As a result, 95% of college students using the Internet showed 5.8% of general knowledge, 56.9% of radiation major, and 45.8% of general education. In the field of Internet use, basic medicine was 71.2%, anatomy 59.5% and physiology 51.6%. Radiation theory was 39.9% in radiation physics, 31.4% in radiation biology, and 18.3% in radiation management. The radiological applications were followed by radiography and radiography in order of 31.4% and 20.3%, respectively. The radiological imaging was 45.8%, MRI was 37.9%, CT was 37.3%, ultrasound was 24.2%, And radiation nuclear medicine 25.5%. The results of the descriptive statistics of the satisfaction of the contents using the Internet media showed that the overall satisfaction was below 2.5 Based on the results of this study, it is necessary to develop a program with high accessibility to provide various opportunities for internet-based opportunities to increase the academic achievement value of major subjects through the internet and to solve the difficulties in the major subject.

• The Korean Journal of Pain
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• 제26권4호
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• pp.336-346
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• 2013

Intrathecal drug delivery is an effective and safe option for the treatment of chronic pathology refractory to conventional pain therapies. Typical intrathecal administered drugs are opioids, baclofen, local anesthetics and adjuvant medications. Although knowledge about mechanisms of action of intrathecal drugs are every day more clear many doubt remain respect the correct location of intrathecal catheter in order to achieve the best therapeutic result. We analyze the factors that can affect drug distribution within the cerebrospinal fluid. Three categories of variables were identified: drug features, cerebrospinal fluid (CSF) dynamics and patients features. First category includes physicochemical properties and pharmacological features of intrathecal administered drugs with special attention to drug lipophilicity. In the second category, the variables in CSF flow, are considered that can modify the drug distribution within the CSF with special attention to the new theories of liquoral circulation. Last category try to explain inter-individual difference in baclofen response with difference that are specific for each patients such as the anatomical area to treat, patient posture or reaction to inflammatory stimulus. We conclude that a comprehensive evaluation of the patients, including imaging techniques to study the anatomy and physiology of intrathecal environment and CSF dynamics, could become essential in the future to the purpose of optimize the clinical outcome of intrathecal therapy.

• Journal of Korean Neurosurgical Society
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• 제53권3호
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• pp.161-166
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• 2013

Objective : Neuroendoscopy is applied to various intracranial pathologic conditions. But this technique needs informations for the anatomy, critically. Neuronavigation makes the operation more safe, exact and lesser invasive procedures. But classical neuronavigation systems with rigid pinning fixations were difficult to apply to pediatric populations because of their thin and immature skull. Electromagnetic neuronavigation has used in the very young patients because it does not need rigid pinning fixations. The usefulness of electromagnetic neuronavigation is described through our experiences of neuroendoscopy for pediatric groups and reviews for several literatures. Methods : Between January 2007 and July 2011, nine pediatric patients were managed with endoscopic surgery using electromagnetic neuronavigation (AxiEM, Medtronics, USA). The patients were 4.0 years of mean age (4 months-12 years) and consisted of 8 boys and 1 girl. Totally, 11 endoscopic procedures were performed. The cases involving surgical outcomes were reviewed. Results : The goal of surgery was achieved successfully at the time of surgery, as confirmed by postoperative imaging. In 2 patients, each patient underwent re-operations due to the aggravation of the previous lesion. And one had transient mild third nerve palsy due to intraoperative manipulation and the others had no surgery related complication. Conclusion : By using electromagnetic neuronavigation, neuroendoscopy was found to be a safe and effective technique. In conclusion, electromagnetic neuronavigation is a useful adjunct to neuroendoscopy in very young pediatric patients and an alternative to classical optical neuronavigation.