• Progress in Medical Physics
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• v.14 no.1
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• pp.34-42
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• 2003

In medical imaging, three-dimensional (3D) display using Virtual Reality Modeling Language (VRML) as a portable file format can give intuitive information more efficiently on the World Wide Web (WWW). The web-based 3D visualization of functional images combined with anatomical images has not studied much in systematic ways. The goal of this study was to achieve a simultaneous observation of 3D anatomic and functional models with planar images on the WWW, providing their locational information in 3D space with a measuring implement using VRML. MRI and ictal-interictal SPECT images were obtained from one epileptic patient. Subtraction ictal SPECT co-registered to MRI (SISCOM) was performed to improve identification of a seizure focus. SISCOM image volumes were held by thresholds above one standard deviation (1-SD) and two standard deviations (2-SD). SISCOM foci and boundaries of gray matter, white matter, and cerebrospinal fluid (CSF) in the MRI volume were segmented and rendered to VRML polygonal surfaces by marching cube algorithm. Line profiles of x and y-axis that represent real lengths on an image were acquired and their maximum lengths were the same as 211.67 mm. The real size vs. the rendered VRML surface size was approximately the ratio of 1 to 605.9. A VRML measuring tool was made and merged with previous VRML surfaces. User interface tools were embedded with Java Script routines to display MRI planar images as cross sections of 3D surface models and to set transparencies of 3D surface models. When transparencies of 3D surface models were properly controlled, a fused display of the brain geometry with 3D distributions of focal activated regions provided intuitively spatial correlations among three 3D surface models. The epileptic seizure focus was in the right temporal lobe of the brain. The real position of the seizure focus could be verified by the VRML measuring tool and the anatomy corresponding to the seizure focus could be confirmed by MRI planar images crossing 3D surface models. The VRML application developed in this study may have several advantages. Firstly, 3D fused display and control of anatomic and functional image were achieved on the m. Secondly, the vector analysis of a 3D surface model was defined by the VRML measuring tool based on the real size. Finally, the anatomy corresponding to the seizure focus was intuitively detected by correlations with MRI images. Our web based visualization of 3-D fusion image and its localization will be a help to online research and education in diagnostic radiology, therapeutic radiology, and surgery applications.

• Journal of Korean Neurosurgical Society
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• v.30 no.8
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• pp.992-997
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• 2001

Objectives : Essential hyperhidrosis is a common condition characterized by excessive body sweating. Excessive sweating beyond what is necessary to maintain normal body temperature need not be considered pathological unless it interferes with one's occupation and/or life-style. The existing non-operative therapeutic options seldom give sufficient relief or show a transient effect. In this regard, the thoracic sympathectomy may provide a definitive cure. In the past, surgical procedures were highly invasive and caused significant morbidity, but the minimally invasive thoracoscopic procedure provided detailed visualization of sympathetic ganglia and is associated with minimally postoperative morbidity. Nowadays, thoracoscopic transthoracic sympathectomy is accepted as the treatment of choice for essential hyperhidrosis. In palmar hyperhidrosis, however, the level of sympathetic chain to be blocked has been somewhat obscure. It is assumed that the incidence of compensatory hyperhidrosis may closely related to the extent of thoracic sympathectomy. Material & Methods : To compare the results of posterior midline approach with endoscopic sympathectomy, and the results of T2 with T2, 3 sympathectomy or sympathicotomy, we retrospectively studied 62 patients treated for palmar hyperhidrosis between September 1993 and May 2000. We reviewed medical records and recently interviewed the patients by telephone calls. Results : The treatment effect of T2 sympathectomy is no different from T2, 3 sympathectomy. But, the incidence of compensatory hyperhidrosis is less in the T2 sympathectomy group than the T2, 3 sympathectomy group. Conclusion : Thoracoscopic sympathectomy is considered a simple, safe, and effective method for treating palmar hyperhidrosis, with a shorter operation time, fewer hospital days, and a better cosmetic result, as compared with the open approaches. However, sympathicotomy seems to provide the advantages of a limited extent of denervation and the resultant decrease of compensatory hyperhidrosis compared to sympathectomy.

• Tuberculosis and Respiratory Diseases
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• v.68 no.1
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• pp.16-21
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• 2010

Background: Lung cancer is usually diagnosed at an advanced stage, resulting in a poor prognosis. The detection of these lesions at an earlier stage would be a clear benefit to patients. However, it is extremely difficult to detect carcinomatous lesions in the bronchial mucosal sites during a routine bronchoscopy. Methods: This study employed a novel optical technique, known as narrowband imaging (NBI), which allows noninvasive visualization of the microvascular structure of an organ's surface using reflected light. Results: Narrow band imaging was performed on 10 patients who were radiologically suspicious or had a high risk of lung cancer. The median age of the patients was 57.5 years (range, 44~81 years), and 80% of the patients were male. All lesions showed a microvascular proliferation pattern (dotted, tortuous and abruptly ending vessel) on the magnified NBI. Two lesions were confirmed histologically to be adenocarcinoma and the remaining lesions were squamous cell carcinomas. Two lesions were confirmed histologically to be a carcinoma in situ. Conclusion: NBI is a promising and potentially powerful tool for identifying carcinomas at an earlier stage or a central lesion during a routine bronchoscopy examination.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2489-2493
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• 2015

Background: Loss of heterozygosity (LOH) on chromosomal regions is crucial in tumor progression and this study aimed to identify genome-wide LOH in pancreatic cancer. Materials and Methods: Single-nucleotide polymorphism (SNP) profiling data GSE32682 of human pancreatic samples snap-frozen during surgery were downloaded from Gene Expression Omnibus database. Genotype console software was used to perform data processing. Candidate genes with LOH were screened based on the genotype calls, SNP loci of LOH and dbSNP database. Gene annotation was performed to identify the functions of candidate genes using NCBI (the National Center for Biotechnology Information) database, followed by Gene Ontology, INTERPRO, PFAM and SMART annotation and UCSC Genome Browser track to the unannotated genes using DAVID (the Database for Annotation, Visualization and Integration Discovery). Results: The candidate genes with LOH identified in this study were MCU, MICU1 and OIT3 on chromosome 10. MCU was found to encode a calcium transporter and MICU1 could encode an essential regulator of mitochondrial $Ca^{2+}$ uptake. OIT3 possibly correlated with calcium binding revealed by the annotation analyses and was regulated by a large number of transcription factors including STAT, SOX9, CREB, NF-kB, PPARG and p53. Conclusions: Global genomic analysis of SNPs identified MICU1, MCU and OIT3 with LOH on chromosome 10, implying involvement of these genes in progression of pancreatic cancer.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.747-750
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• 2008

Although surgical closure is the standard approach for a muscular ventricular septal defect, the procedure may be complicated by poor visualization and the need for incision on the ventricle. Another approach is, catheter-based intervention. However, it also has limitations. A hybrid procedure, the intraoperative combined use of an interventional device may reduce the procedure's invasiveness. We successfully managed two cases of muscular ventricular septal defect with a hybrid procedure. We report here on these 2 cases along with a review of the literature.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.201-205
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• 1997

With the recent advance of Web and its associated technologies, information sharing on distribute computing environments has gained a great amount of attention from many researchers in many application areas, such as medicine, engineering, and business. One basic requirement of distributed medical consultation systems is that geographically dispersed, disparate participants are allowed to exchange information readily with each other. Such software also needs to be supported on a broad range of computer platforms to increase the software's accessibility. In this paper, the development of world-wide-web based medical consultation system or radiology imaging is addressed to provide the platform independence and great accessibility. The system supports sharing of 3-dimensional objects. We use VRML (Virtual Reality Modeling Language), which is the de-facto standard in 3-D modeling on the Web. 3-D objects are reconstructed from CT or MRI volume data using a VRML format, which can be viewed and manipulated easily in Web-browsers with a VRML plug-in. A Marching cubes method is used in the transformation of scanned volume data set to polygonal surfaces of VRML. A decimation algorithm is adopted to reduce the number of meshes in the resulting VRML file. 3-D volume data are often very large-sized, and hence loading the data on PC level computers requires a significant reduction of the size of the data, while minimizing the loss of the original shape information. This is also important to decrease network delays. A prototype system has been implemented (http://netopia.snu.ac.kr/-cyber/). and several sessions of experiments are carried out.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.53-60
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• 1991

Extracorporeal shock wave lithotripsy (ESWL) with adjunctive oral litholytic therapy has proven to be a useful treatment in selected patients with gallbladder stones. To study the effect of ESWL on gallbladder dynamics, $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy was done for 25 patients with symptomatic gallstones and 10 normal controls. Of these 25 patients, 15 were treated with ESWL and adjunctive oral litholytic agents (ESWL group) and 10 were treated only with oral litholytic agents (UDCA group). After overnight fast and gallbladder visualization on a routine hepatobiliary scintigraphy with 7mCi of $^{99m}Tc-DISIDA$, subjects were given fatty meal and imaged with a gamma camera interfaced to a computer (1 frame/minute for 70 minutes). A gallbladder time-activity curve was generated and latent period (LP), ejection period (EP), ejection fraction (EF) and ejection rate (ER) were calculated. ESWL group were studied before, 1day after and 2weeks after ESWL, and WDCA group were studied before and 2weeks after starting oral medication. Mean basal EF was significantly reduced in patients but other parameters were not reduced. In ESWL group, mean EF and mean ER at lday after ESWL were reduced. In 3 of them, gallbladder was not visualized at all. Two weeks after ESWL, however, all parameters were recoverd to basal level. In UDCA group, all parameters were not changed significantly during medication. We can conclude that ESWL has such immediate adverse effect on gallbladder dynamics as reducing contractility and nonvisualization of gallbladder but it has no long-term effect.

• Archives of Plastic Surgery
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• v.49 no.5
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• pp.676-682
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• 2022

Background Virtual education is an evolving method for teaching medical learners. During the coronavirus disease 2019 pandemic, remote learning has provided a replacement for conferences, lectures, and meetings, but has not been described as a method for conducting a cadaver dissection. We aim to demonstrate how learners perceive a virtual cadaver dissection as an alternative to live dissection. Methods A virtual cadaver dissection was performed to demonstrate several upper extremity nerve procedures. These procedures were livestreamed as part of an educational event with multimedia and interactive audience questions. Participants were queried both during and after the session regarding their perceptions of this teaching modality. Results Attendance of a virtual dissection held for three plastic surgery training institutions began at 100 and finished with 70 participants. Intrasession response rates from the audience varied between 68 and 75%, of which 75% strongly agreed that they were satisfied with the virtual environment. The audience strongly agreed or agreed that the addition of multimedia captions (88%), magnified video loupe views (82%), and split-screen multicast view (64%) was beneficial. Postsession response rate was 27%, and generally reflected a positive perspective about the content of the session. Conclusions Virtual cadaver dissection is an effective modality for teaching surgical procedures and can be enhanced through technologies such as video loupes and multiple camera perspectives. The audience viewed the virtual cadaver dissection as a beneficial adjunct to surgical education. This format may also make in-person cadaver courses more effective by improving visualization and allowing for anatomic references to be displayed synchronously.

• Molecules and Cells
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• v.45 no.11
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• pp.846-854
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• 2022

Neurons make long-distance connections via their axons, and the accuracy and stability of these connections are crucial for brain function. Research using various animal models showed that the molecular and cellular mechanisms underlying the assembly and maintenance of neuronal circuitry are highly conserved in vertebrates. Therefore, to gain a deeper understanding of brain development and maintenance, an efficient vertebrate model is required, where the axons of a defined neuronal cell type can be genetically manipulated and selectively visualized in vivo. Placental mammals pose an experimental challenge, as time-consuming breeding of genetically modified animals is required due to their in utero development. Xenopus laevis, the most commonly used amphibian model, offers comparative advantages, since their embryos ex utero during which embryological manipulations can be performed. However, the tetraploidy of the X. laevis genome makes them not ideal for genetic studies. Here, we use Xenopus tropicalis, a diploid amphibian species, to visualize axonal pathfinding and degeneration of a single central nervous system neuronal cell type, the retinal ganglion cell (RGC). First, we show that RGC axons follow the developmental trajectory previously described in X. laevis with a slightly different timeline. Second, we demonstrate that co-electroporation of DNA and/or oligonucleotides enables the visualization of gene function-altered RGC axons in an intact brain. Finally, using this method, we show that the axon-autonomous, Sarm1-dependent axon destruction program operates in X. tropicalis. Taken together, the present study demonstrates that the visual system of X. tropicalis is a highly efficient model to identify new molecular mechanisms underlying axon guidance and survival.

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.193-198
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• 2022

Contrast enhanced magnetic resonance imaging using gadolinium-based contrast agent (GBCA) is a very useful in vivo technique to visualize the inner ear pathology including endolymphatic hydrops. Although systemic intravenous (IV) administration can visualize the perilymph space, the visualization was possible by indirect passage of contrast agent through blood-perilymph barrier. All animal experimental procedures were performed under anesthesia with 5% isoflurane. Lipopolysaccharide (LPS) was instilled into the left tympanic cavity through the tympanic membrane using a sterile 27gauge needle to induce hydrops model. Tucker-Davis Technologies system was used to measure Auditory Brainstem Responses (ABRs). For intracerebroven-tricular (ICV) administration, 25 µmol of GADOVIST (Bayer, Berlin, Germany) was used and diluted GADOVIST injection was 10 µl. MR imaging was acquired with a 9.4 Tesla MRI scanner. Transmit-receive volume coil with 40 mm inner diameter and 75 mm out diameter was used. ICV administration well demonstrated the strong enhancement along the cerebrospinal fluid (CSF) microcirculation pathway including CSF fluid in the subarachnoid space and CSF space of the inner ear structures. On the other hand, IV administration showed no contrast enhancement along the CSF microcirculation pathway and showed weak enhancement in the inner ear structures. In case of rat hydrops model, ICV administration showed that the reduced contrast enhancement in the perilymph space of the hydrops induced inner ear compared to the contrast enhancement in the perilymph space of the normal inner ear. New systemic ICV administration method provide contrast enhancement of GBCA in the inner ear through CSF microcirculation pathway.