• 구강회복응용과학지
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• 제29권1호
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• pp.23-36
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• 2013

이 연구의 목적은 상악동 골증대술과 동반된 이식된 골의 3차원적인 형태를 평가하고 골이식 재료 및 임플란트의 종류, 수술 방법과 골흡수 정도 사이의 관계를 평가하는 것이다. 임플란트 식립을 위한 상악동 골증대술을 시행받은 환자들의 차트를 후향적으로 검토하였고 골이식재의 부피 및 부위의 방사선학적 분석을 시행하였다. 임플란트 식립 6개월 후 잔존 골 이식재의 비율로 측정된 부피 재생은 이식 재료의 형태 및 수술 방법과 연관성이 있었다. 원광대학교 산본 치과병원에서 15명의 환자에서 상악동 골이식술과 동반하여 53개의 임플란트가 식립되었다. 임플란트 식립 6개월 후 촬영된 컴퓨터 단층촬영에서 $Puros^{(R)}$ 와 다른 여러 가지 골이식재를 혼용한 그룹에비해 $Puros^{(R)}$ 이식재를 단독으로 사용한 그룹에서 더 높은 골흡수 정도를 보였다 (P<0.05). 그리고 수술 방법에 따른 골흡수 정도는 통계학적으로 유의성있는 차이를 보였다 (P<0.05). 골이식과 동시에 임플란트를 식립한 그룹에 비해 지연된 임플란트 식립을 시행한 그룹에서 더 높은 골이식재의 부피 변화율을 보였다. 후향적 자료 분석을 통해 $Puros^{(R)}$ 와 다른 여러 가지 골이식재를 혼용한 그룹에 비해 $Puros^{(R)}$ 이식재를 단독으로 사용한 그룹에서 더높은 골흡수 정도를 보였다. 또한 골이식과 동시에 임플란트를 식립한 그룹에서 지연 식립한 그룹보다 더 낮은 흡수율을 보여주었다.

• Journal of Korean Neurosurgical Society
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• 제49권6호
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• pp.355-358
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• 2011

Objective : Subdural hygroma (SDG) is a complication occurring after head trauma that may occur secondary to decompressive craniectomy (DC). However, the mechanism underlying SDG formation is not fully understood. Also, the relationship between the operative technique of DC or the decompressive effect and the occurrence and pathophysiology of SDG has not been clarified. Purpose of this study was to investigate the risk factors of SDG after DC in our series. Methods : From January 2004 to December 2008, DC was performed in 85 patients who suffered from traumatic brain injury. We retrospectively reviewed the clinical and radiological features. For comparative analysis, we divided the patients into 2 groups : one group with SDG after craniectomy (19 patients; 28.4% of the total sample), the other group without SDG (48 patients; 71.6%). The risk factors for developing SDG were then analyzed. Results : The mean Glasgow Outcome Scale (GOS) scores at discharge of the groups with and without SDG were 2.8 and 3.1, respectively (p<0.0001). Analysis of radiological factors showed that a midline shift in excess of 5 mm on CT scans was present in 19 patients (100%) in the group with SDG and in 32 patients (66.7%) in the group without SDG (p<0.05). An accompanying subarachnoid hemorrhage (SAH) was seen in 17 patients (89.5%) in the group with SDG and in 29 patients (60.4%) in the group without SDG (p<0.05). Delayed hydrocephalus accompanied these findings in 10 patients (52.6%) in the group with SDG, versus 5 patients (10.4%) in the group without SDG (p<0.05). On CT, compression of basal cisterns was observed in 14 members (73.7%) in the group with SDG and in 18 members of the group without SDG (37.5%) (p<0.007). Furthermore, tearing of the arachnoid membrane, as observed on CT, was more common in all patients in the group with SDG (100%) than in the group without SDG (31 patients; 64.6%) (p<0.05). Conclusion : GOS showed statistically significant difference in the clinical risk factors for SDG between the group with SDG and the group without SDG. Analysis of radiological factors indicated that a midline shifting exceeding 5 mm, SAH, delayed hydrocephalus, compression of basal cisterns, and tearing of the arachnoid membrane were significantly more common in patients with SDG.

• Journal of Korean Neurosurgical Society
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• 제61권4호
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• pp.503-508
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• 2018

Objective : Anterior odontoid screw fixation is a safe and effective method for the treatment of odontoid fractures. The surgical technique is recommended for perforation of the apical cortex of the dens by the lag screw. However, overpenetration of the apical cortex may lead to potentially serious complications such as damages of adjacent vascular and neural structures. The purpose of this study was to assess the role of three-dimensional computed tomography (CT) scan to evaluate the safe margin beyond dens tip to ventral dura for anterior odontoid screw fixation. Methods : We retrospectively analyzed the three-dimensional CT scans of the cervical spines in 55 consecutive patients at our trauma center. The patients included 38 males and 17 females aged between 22 and 73 years (mean age${\pm}$standard deviation, $45.8{\pm}14.2years$). Using sagittal images of 3-dimensional CT scan, the safe margins beyond dens tip to ventral dura as well as the appropriate screw length were measured. Results : The mean width of the apical dens tip was $9.6{\pm}1.1mm$. The mean lengths from the screw entry point to the apical dens tip and posterior end of dens tip were $39.2{\pm}2.6mm$ and $36.6{\pm}2.4mm$. The safe margin beyond apical dens tip to ventral dura was $7.7{\pm}1.7mm$. However, the safe margin beyond the posterior end of dens tip to ventral dura was decreased to $2.1{\pm}3.2mm$, which was statistically significant (p<0.01). There were no significant differences of safe margins beyond dens tip to ventral dura with patient gender and age. Conclusion : Extension by several millimeters beyond the dens tip is safe, if the trajectory of anterior odontoid screw is targeted at the apical dens tip. However, if the trajectory of the screw is targeted to the posterior end of dens tip, extension beyond dens tip may lead to damage immediately adjacent to the vental dura mater.

• 대한두개안면성형외과학회지
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• 제10권1호
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• pp.7-13
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• 2009

Purpose: Endoscopic transnasal correction of the medial orbital fractures cannot be enable to confirm the reduction degree of orbital volume without imaging modalities. We have intended through this study to make a quantative analysis of preoperative orbital volume increment and the reduction degree of that after ethmoidal sinus packing by using CT scan. Methods: In this retrospective study, 22 patients were selected to evaluate the postoperative volume reduction, who took 2 CT scans which are pre- and postoperative under the same protocol. The postoperative CT scan was carried out in about 5 days after the operation with the packing inserted into ethmoidal sinus. The length of bony defect on each section was measured by PACS program and the area of defect was calculated by summing lengths on each section multiplied by the thickness of the section. When the outline of orbit on the slice is drawn manually with a cursor, PACS program measures the area automatically. Orbital volume was calculated from the sum of the area multiplied by the section thickness. Results: The mean dimension of fractured walls was $2.86{\pm}0.99cm^2$. The mean orbital volume of the unaffected orbits was $22.89{\pm}2.15cm^3$ and that of the affected orbits was $25.62{\pm}2.82cm^3$. The mean orbital volume increment of the affected orbits was $2.73{\pm}1.13cm^3$. After surgery, the mean orbital volume of the unaffected orbits was $22.46{\pm}2.73cm^3$ and the mean orbital volume decrease on the surgical side was $2.98{\pm}1.07cm^3$. The estimated correction rate was 118.30%. Conclusion: The orbital volume increment in fractured orbit showed linear correlation with the dimension of fractured area. The orbital volume changes after ethmoidal sinus packing also showed linear correlation with orbital volume increment in fractured orbit. This study showed the regressive linear correlation between the increment of orbital volume and the correction rate. To evaluate the maintenance of reduction state, we think that the further study should be done for comparative analysis of orbital volume change after removal of packing.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• 전자공학회논문지CI
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• 제47권1호
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• pp.65-72
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• 2010

오늘날 의료 기관에서는 수많은 의료 영상자료를 만들고 관리하고 있으며, 이러한 자료들 중에서는 환자의 프라이버시와 관련된 정보도 많다. 따라서 이러한 개인정보는 외부로 노출되어서는 안 되며, 철저한 관리가 필요하다. 본 논문에서는 이러한 프라이버시 관련 영상 자료에 환자의 상태 및 의료 처방 정보를 포함함으로서, 향후 영상자료의 관리 소홀로 인한 잘못된 의료처방 등을 방지할 수 있는 방안을 제안한다. 제안한 방법은 각 환자 정보에 대한 HMAC 기반의 해쉬 코드를 생성하고, 생성된 코드와 환자의 정보를 함께 이미지에 포함함으로서 향후 의사가 이 이미지로부터 추출한 데이터가 외부인에게 훼손되었는지 여부를 쉽게 감지함으로써, 환자의 정보를 보다 철저히 관리할 수 있도록 하는 것을 목적으로 한다. 또한, 환자의 의료정보를 이미지에 은닉하기 위해서 복원 가능한 데이터 은닉 기법인 DE(Difference Expansion) 알고리즘을 사용함으로서, 이미지로부터 데이터를 추출한 후 원 영상을 가지고, 환자의 상태를 쉽게 체크할 수 있게 되어 의사의 입장에서 매우 효율적인 방법으로 환자 상태를 평가할 수 있다. 제안한 방법은 뇌 영상을 촬영한 MRI 영상에서 실험한 결과 데이터은닉과 추출 그리고 영상의 복원 그리고 데이터 무결석 확인에 있어서 완벽한 성능을 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.2925-2929
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• 2013

Objective: To explore the relationships between primary tumor $^{18}F$-FDG uptake measured as the SUVmax and local extension, and nodal or distant organ metastasis in patients with NSCLC on pretreatment PET-CT. Methods: 93 patients with NSCLC who underwent $^{18}F$-FDG PET-CT scans before the treatment were included in the study. Primary tumor SUVmax was calculated; clinical stages, presence of local extension, nodal and distant organ metastases were recorded. The patients with SUVmax${\geq}2.5$ were divided into low and high SUVmax groups by using the median SUVmax. The low SUVmax group consisted of 45 patients with SUVmax<10.5, the high SUVmax group consisted of 46 patients with SUVmax${\geq}10.5$. Their data were compared statistically. Results: 91 cases with SUVmax${\geq}2.5$ were included for analysis. The mean SUVmax in patients without any metastasis was $7.42{\pm}2.91$ and this was significantly lower than that ($12.18{\pm}4.94$) in patients with nodal and/or distant organ metastasis (P=0.000). In the low SUV group, 19 patients had local extension, 22 had nodal metastasis, and 9 had distant organ metastasis. In the high SUV group, 31 patients had local extension, 37 had nodal metastasis, and 18 had distant organ metastases. There was a significant difference in local extension (P =0.016), distant organ metastasis (P =0.046), and most significant difference in nodal metastasis rate (P =0.002) between the two groups. In addition, there was a moderate correlation between SUVmax and tumor size (r = 0.642, P<0.001), tumor stage (r = 0.546, P<0.001), node stage (r = 0.388, P<0.001), and overall stage (r = 0.445, P= 0.000). Conclusion: Higher primary tumor SUVmax predicts higher extensional or metastatic potential in patients with NSCLC. Patients with higher SUVmax may need a close follow-up and more reasonable individual treatment because of their higher extensional and metastatic potential.

• 대한치과교정학회지
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• 제35권5호
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• pp.388-397
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• 2005

이 연구는 기존의 두부방사선사진에서 사용되었던 계측점들을 3차원으로 재구성한 CT자료에서 다시 정의하고, 그 점들의 재현도를 조사함으로써. 재현성이 높고 해부학적 특징을 잘 표현하는 점들을 제안하고자 시행하였다. 3차원 영상에서 상대적 좌표 값을 구하기 위해 어느 4점도 같은 평면에 존재하지 않는 7개의 고정점을 선정하여 기준 좌표계를 설정하였다. V works 4.0 (Cybermed inc., Seoul. Korea)을 이용하여 고정점과 1점 설정을 위한 volume model (voxel size=4*4*2, threshold value-639)을 형성한 후 계측점을 선택하였으며. 나머지 점들은 모두 volume mode의 MPR 창을 이용하여 선정하였다 이렇게 선정한 계측점을 V 녁ㅎㄷ교 (Cybermed Inc.. Seoul, Korsa)로 이출하여 각 점의 상대적 공간 좌표 값을 구하였다 모든 자료는 2주 간격으로 2번 측정한 후 재현도를 계산하였다 각 계측점의 재현도는 x축 $0.13\~1.24mm$, y축 $0.23\~1.53mm$, z축 $0.15\~1.81mm$로 유사한 범위를 보였다 재현도가 우수한 것은 고정점을 이용한 1점이며 봉합에 의해 정의되는 J점의 재현도가 비교적 낮게 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.566-574
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• 2006

Purpose : This study was performed to provide an anatomical information of the mandibular ramus for the successful inferior alveolar nerve block. Three dimensional images were reconstructed from the computerized tomography (CT) and the anatomical evaluation of the mandibular ramus was done. Materials and methods : Sixty-four patients who had been taken the facial CT scans from 2000, Jan to 2003, June was selected. The patients who had the anterior or posterior teeth misssing, edentulous ridge, and jaw fracture were excepted. In the occulusal plane, the lingual surface angle (LSA) between the mid-sagittal plane and the mandibular molar lingual surface from the 2nd premolar to the 2nd molar, the inner ramal surface angle (IRSA), the maximum inner ramal surface angle (MxIRSA), and the outer ramal surface angle (ORSA) to the-mid sagittal plane were measured. The inner ramal surface angle in the ligular tip level (IRSA-L) and the outer ramal surface angle in the ligular tip level (ORSA-L), the ramal length (RL), and the anterior ramal length (ARL) were also measured in the lingular tip level. Results : In the lingular tip level, the mean IRSA-L and ORSA-L were $28.6{\pm}6.3^{\circ}$ and $17.9{\pm}4.9^{\circ}$ respectively. The larger was the IRSA, the larger was the ORSA. In the lingular tip level, the mean ramal length was 35.8${\pm}$3.4 mm. The larger was the IRSA-L, the shorter was the ramal length. On the lingular tip level, the mean anterior ramal length from anterior ramus to lingular tip was 19.6${\pm}$3.3 mm. when the ramal length was longer, the anterior ramal length was also longer. On the lingular tip level, there was positive correlation vetween the IRSA and the ORSA, negative correlation between the IRSA and the ramal length, and positive correlation between the ramal length and the lingular tip level to the anterior ramus. There was no statistical meaning of data between sex and age. Conclusion : In the clinical view of the results so far achieved, if the direction of needle is closer to posterior it is able to contact bone on lingular tip when the internal surface of ramus is wided outer.

• Korean Journal of Radiology
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• 제21권10호
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• pp.1178-1186
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• 2020

Objective: To evaluate the incidence and risk factors of emetic complications associated with the intravenous administration of low-osmolality iodinated contrast media (ICM) in children undergoing computed tomography (CT). Materials and Methods: All children who underwent contrast-enhanced CT between April 2017 and July 2019 were included. Pediatric patients were instructed on the preparative dietary protocol at our institution. Experienced nurses in the radiology department monitored the children during the CT scans and recorded any emetic complications in their electronic medical records. These data were used to calculate the incidence of emetic complications. Various patient factors and technical factors, including fasting duration, the type and volume of ICM, and ongoing chemotherapy, were evaluated to identify risk factors for emetic complications using univariate and multivariate logistic regression analyses. Results: Among the 864 children (mean age, 8.4 ± 5.7 years) evaluated, 18 (2.1%) experienced emetic complications (6 experienced nausea only and 12 experienced nausea and vomiting). None of the children developed aspiration pneumonia. The mean fasting duration of patients with emesis was 7.9 ± 5.7 hours (range, 3-21 hours), whereas that of patients without nausea was 8.7 ± 5.7 hours (range, 0-24 hours). Fasting duration was not associated with the development of nausea and vomiting (p = 0.634). Multivariate logistic regression analysis revealed that ongoing chemotherapy (odds ratio [OR] = 4.323; 95% confidence interval [CI] = 1.430-13.064; p = 0.009), iomeprol use (OR = 7.219; 95% CI = 1.442-36.146; p = 0.016), and iohexol use (OR = 5.241; 95% CI = 1.350-20.346; p = 0.017) were independent risk factors for emetic complications. Conclusion: Only a small proportion (2.1%) of children experienced nausea or vomiting after exposure to low-osmolality ICM. Many children underwent excessive fasting; however, fasting duration was not associated with nausea and vomiting. Moreover, ongoing chemotherapy and the use of iomeprol or iohexol were identified as potential risk factors for emetic complications in children.