• The Journal of Advanced Prosthodontics
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• v.14 no.2
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• pp.88-95
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• 2022

PURPOSE. This study investigated the accuracy of full-arch intraoral scans obtained by various scan strategies with the segmental scan and merge methods. MATERIALS AND METHODS. Seventy intraoral scans (seven scans per group) were performed using 10 scan strategies that differed in the segmental scan (1, 2, or 3 segments) and the scanning motion (straight, zigzag, or combined). The three-dimensional (3D) geometric accuracy of scan images was evaluated by comparison with a reference image in an image analysis software program, in terms of the arch shape discrepancies. Measurement parameters were the intermolar distance, interpremolar distance, anteroposterior distance, and global surface deviation. One-way analysis of variance and Tukey honestly significance difference post hoc tests were carried out to compare differences among the scan strategy groups (α = .05). RESULTS. The linear discrepancy values of intraoral scans were not different among scan strategies performed with the single scan and segmental scan methods. In general, differences in the scan motion did not show different accuracies, except for the intermolar distance measured under the scan conditions of a 3-segmental scan and zigzag motion. The global surface deviations were not different among all scan strategies. CONCLUSION. The segmental scan and merge methods using two scan parts appear to be reliable as an alternative to the single scan method for full-arch intraoral scans. When three segmental scans are involved, the accuracy of complete arch scan can be negatively affected.

• The Korean Journal of Nuclear Medicine
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• v.19 no.2
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• pp.57-63
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• 1985

To evaluate the clinical significance of lung ventilation scan using $^{99m}Tc-DTPA$ in patient with bronchiectasis, we compared the involovement area of bronchogram and lung ventilation scan according to lobar and segmental distribution. There were no correlation between impairment of pulmonary function test and the number of bronchiectatic lobe and segment(p>0.5). Lung ventilation scan showed 66.7% of sensivity, 100% of specificity, ana 91.7% of accuracy according to lobar distribution, and 51.9% of sensivity, 96.9% of specificity, and 88.9% of accuracy according to segmental distribution. These results suggest that lung ventilation scan can be used as diagnostic tool in patient with bronchiectasis in whom bronchogram is not tolerable.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.193-200
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• 2005

Purpose : An atrophic renal scar(RS) is one of the underlying causes for childhood hyper tension and chronic renal failure. The risk factors for atrophic renal scar were evaluated. Methods : 41 children, who presented with first febrile urinary tract Infection at the Ewha Womans University Hospital between 1995 and 2003 and had generalized atrophic RS on $^{99m}Tc-DMSA$ renal scan, were retrospectively studied. Atrophic RS was divided into severe atrophic RS(n=14) if relative uptake on renal scan was below 10$\%$, or mild atrophic RS(n=27) if relative uptake on renal scan was between 10-35$\%$. RS was defined as congenital if the scar was detected on the first renal scan, and as acquired if the scar developed on the follow-up renal scan from acute pyelonephritis of the first renal scan. The control group was consisted of randomly selected 41 children with segmental RS. The risk factors for atrophic RS such as the generation time, VUR, gender and ACE gene polymorphism were evaluated. Results : The age distribution of atrophic RS and segmental RS did not differ significantly (P>0.05). The rate of congenital RS in atrophic RS was 61.0$\%$(25/41), which was significantly higher than 9.8$\%$(4/41) of segmental RS(P<0.01). Atrophic RS developed mote frequently in male children(M:F 68.3$\%$ 31.7$\%$) than segmental RS(M:F 41.4$\%$ .58.5$\%$)(P<0.05). Vesicoureteral reflux(VUR) was found in 92.7$\%$(38/41) of 4he atrophic RS, which was significantly higher than 53.7$\%$(22/41) of segmental RS(P<0.05). In children without VUR, the male to female ratio did not differ between atrophic RS and segmental RS(P>0.05) But in children with VUR, there was a higher proportion of males with severe atrophic RS than segmental RS($85.7\%:45.5\%$) ACE gene polymorphism did not differ between the atrophic and segmental RS groups, irrespective of the presence of VUR(P>0.05). Conclusion : Most atrophic RSs were congenital which could not be preventable postnatally and the major risk factors were VUR and the male gender. ACE gene polymorphism was not the significant risk factor for an atrophic RS. (J Korean Soc Pedialr Nephrol 2005;9:193-200)

• The Korean Journal of Nuclear Medicine
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• v.32 no.2
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• pp.161-167
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• 1998

Purpose: Segmental parenchymal excretion delay on Tc-99m DISIDA scan is caused by intrahepatic bile duct obstruction. However, the diagnostic value for intrahepatic bile duct obstruction is unknown. We conducted this study to assess the positive predictive value of segmental excretion delay for the diagnosis of intrahepatic bile duct obstruction, and additional benefit over other noninvasive radiologic studies. Materials and Methods: The study population consisted of 43 patients (48 scans) who showed segmental parenchymal excretion delay on Tc-99m DISIDA scan. The results of abdominal CT or ultrasonography, which was done within 1 month of Tc-99m DISIDA scan, were compared with scintigraphic findings. Results: The etiology of segmental parenchymal excretion delay was determined by ERC or PTC in 31 scans, and follow-up studies in 13 scans. No causes were identified in 4 scans. The positive predictive value of segmental parenchymal excretion delay for intrahepatic bile ductobstruction was 92% (44/48). On the other hand, 13% (5/38) of CT and 28% (5/18) of ultrasonography were normal. In 18% (7138) of CT and 17% (3/18) of ultrasonography, only intraheipatic bile duct dilatation was noted without any diagnostic findings of intrahepatic bile duct obstruction. Conclusion: Segmental parenchymal excretion delay on Tc-99m DISIDA scan had a high positive predictive value for the diagnosis of intrahepatic bile duct obstruction. Tc-99m DISIDA scan may be useful for the diagnosis of intrahepatic bile duct obstruction, especially in patients with nondiagnostic CT or ultrasonography. The diagnostic usefulness need to be confirmed by further prospective studies.

• Journal of Korean Neurosurgical Society
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• v.49 no.2
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• pp.131-133
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• 2011

We performed a percutaneous vertebroplasty at the compressed L2 vertebral body of a 73-year-old female using a left-sided unilateral extrapedicular approach. She complained severe radiating pain and a tingling sensation in her left leg two hours after the vertebroplasty. Spinal computed tomographic scan showed a large retroperitoneal hematoma, and a subsequent spinal angiography revealed a left L2 segmental artery injury. Bleeding was successfully controlled by endovascular embolization. Recently, extrapedicular approaches have been attempted, allowing for the avoidance of facet and pedicle injury with only a unilateral approach. With this approach, however, the needle punctures the vertebral body directly. Therefore, this procedure carries the potential risk of a spinal segmental artery.

• Journal of Korean Neurosurgical Society
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• v.45 no.3
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• pp.192-195
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• 2009

We present a case of an acute psoas muscle hematoma following percutaneous endoscopic lumbar discectomy. A 60-year-old female who presented with far lateral lumbar disc herniation underwent endoscopic discectomy on the right side at the L4-5 level. On the second postoperative day, the patient complained of severe right flank and leg pain and her blood pressure decreased. A computed tomography scan showed a large acute psoas muscle hematoma at right L4-5 level. The patient was transfused with packed red blood cells and placed at absolute bed rest. After observing the patient in intensive care, the severe flank and leg pain subsided, but the mild back pain persisted. Although percutaneous endoscopic lumbar discectomy is an effective minimally invasive surgical technique for the treatment of lumbar disc herniation, this case highlights the inherent risks of acute lumbar segmental vessel injury.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.584-587
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• 2014

In the present study, a fibular osteotomy guide based on a computer simulation was applied to a patient who had undergone mandibular segmental ostectomy due to oncological complications. This patient was a 68-year-old woman who presented to our department with a biopsy-proven squamous cell carcinoma on her left gingival area. This lesion had destroyed the cortical bony structure, and the patient showed attenuation of her soft tissue along the inferior alveolar nerve, indicating perineural spread of the tumor. Prior to surgery, a three-dimensional computed tomography scan of the facial and fibular bones was performed. We then created a virtual computer simulation of the mandibular segmental defect through which we segmented the fibular to reconstruct the proper angulation in the original mandible. Approximately 2-cm segments were created on the basis of this simulation and applied to the virtually simulated mandibular segmental defect. Thus, we obtained a virtual model of the ideal mandibular reconstruction for this patient with a fibular free flap. We could then use this computer simulation for the subsequent surgery and minimize the bony gaps between the multiple fibular bony segments.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.332-336
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• 2012

Objectives: This study sought to evaluate fixation methods and determine the best method for the postoperative stabilization of maxillary osteotomy. For our analysis we performed a three-dimensional finite element analysis of stress distribution on the plate, screw, and surrounding bone, as well as displacement onto the plate. Materials and Methods: We generated a model using synthetic skull scan data; an initital surface model was changed to a solid model using software. Modified anterior segmental osteotomy (using Park's method) was made using the program, and four different types of fixation methods were used. An anterior load of 100 N was applied on the palatal surface of two central incisors. Results: The Type 1 (L-shaped) fixation method gave stresses of 187.8 MPa at the plate, 45.8 MPa at the screw, and 15.4 MPa at the bone around the plate. The Type 2 (I-shaped) fixation method gave stresses of 186.6 MPa at the plate, 75.7 MPa at the screw, and 13.8 MPa at the bone around the plate. The Type 3 (inverted L-shaped) fixation method gave stresses of 28.6 MPa at the plate, 29.9 MPa at the screw, and 15.3 MPa at the bone around the plate. The Type 4 (I-shaped) fixation method gave stresses of 34.8 MPa at the plate, 36.9 MPa at the screw, and 14.9 MPa at the bone around the plate. The deflection of the plates for the four fixation methods was 0.014 mm, 0.022 mm, 0.017 mm, and 0.018 mm, respectively. Conclusion: The Type 3 (inverted L-shaped) fixation method offers more stability than the other fixation methods. We therefore recommend this method for the postoperative stabilization of maxillary osteotomy.

• Advances in pediatric surgery
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• v.7 no.1
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• pp.42-45
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• 2001

The major complications of Meckel's diverticulum (MD) are bleeding, intestinal obstruction, infection, umbilical fistula and perforation. Although the relative incidences vary between authors, bleeding is the most common complication in children. The aim of our study is to show the symptomatic guideline for the diagnosis of the bleeding MD. Eight cases with bleeding MD which were operated upon at the department of Pediatric Surgery, Yeungnam University Hospital from April 1985 to April 2001 were reviewed. Half of the patients were under 2 years of age and all patient s we re male. All patients were preoperatively diagnosed by previous history of intestinal bleeding (melena, hematochezia) and 99mTc pertechnetate MD scan. Segmental resection and end-to-end anastomosis was performed in 6 patients and diverticulectomy in 2 patients. Heterotropic gastric mucosa was found in 6 patients. Postoperative complication was not observed in any cases. In conclusion, in any male children with obscure intestinal bleeding, especially less than 2 years of age, bleeding MD must be suspected. It seems to us that 99mTc pertechnetate MD scan is a useful tool to diagnose bleeding MD.

• Journal of Chest Surgery
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• v.28 no.5
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• pp.495-498
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• 1995

Pulmonary arteriovenous fistula can be either congenital or acquired. The vast majority are congenital, and about 60% have been associated with hereditary hemorrhagic telangiectasia [Rendu-Osler-Weber disease . Secondary or acquired pulmonary arteriovenous fistula occurs with trauma, schistosomiasis, long-standing hepatic cirrhosis, metastatic carcinoma, and actinomycosis. Pulmonary hemorrhage secondary to acquired pulmonary arteriovenous fistula is a rare event associated with mortality. We have experienced 64 year-old female patient with the hemoptysis secondary to acquired pulmonary arteriovenous fistula due to the infection of pulmonary parasite. The chest PA and CT scan was showed calcified nodule to the distal portion of lateral segmental bronchus of RML. The bronchial angiogram was demonstrated slightly hypertrophied bronchial artery supplying RML bronchus and the presence of hypervascularization around the calcified nodule, rapid A-V shunting is noted by fluoroscopy. The patient was successfully treated by the right middle lobectomy.