하악 무치악 부위의 임플란트 이식을 위한 전산화단층촬영 영상의 비교 평가

선경훈,정호걸,박혁,박창서,김기덕 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.1

Purpose : The purpose of this study was to evaluate the clinical usefulness of the recently developed multi-detector computed tomography and cone beam computed tomography in pre-operative implant evaluation, by comparing them with the single detector computed tomography, already confirmed for accuracy in this area. Materials and Methods : Five partially edentulous dry human mandibles, with 1×1 mm gutta percha cones, placed in 5 mm intervals posterior to the mental foramen on each side of the buccal part of the mandible, were used in this study. They were scanned as follows: 1) Single detector computed tomography: slice thickness 1 mm, 200 mA, 120 kV 2) Multi-detector computed tomography: slice thickness 0.75 mm, 250 mA, 120 kV 3) Cone beam computed tomography: 15 mAs, 120 kV Axial images acquired from three computed tomographies were transferred to personal computer, and then reformatted cross-sectional images were generated using V-Implant 2.0 (CyberMed Inc., Seoul, Korea) software. Among the cross-sectional images of the gutta percha cone, placed in the buccal body of the mandible, the most precise cross section was selected as the measuring point and the distance from the most superior border of the mandibular canal to the alveolar crest was measured and analyzed 10 times by a dentist. Results : There were no significant intraobserver differences in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). There were no significant differences among single detector computed tomography, multi-detector computed tomography and cone beam computed tomography in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). Conclusion : Multi-detector computed tomography and cone beam computed tomography are clinically useful in the evaluation of pre-operative site for mandibular dental implants, with consideration for radiation exposure dose and scanning time.

Comparison of Cup Setting Angle Accuracy between Computed Tomography-Based and Computed Tomography-Free Navigation in the Same Patients with Crowe’s Classification I or II Hip Dysplasia

Nobuhiro Kaku,Hiroaki Tagomori,Hiroshi Tsumura 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.2

Background: In total hip arthroplasty, the cup setting angle may affect the postoperative results. In recent years, both computed tomography-based navigation and computed tomography-free (imageless) navigation have been reported to produce high accuracy in cup installation; however, no direct comparison between these two methods has been performed. The present study aimed to directly compare the cup installation angle accuracy between computed tomography-based navigation and computed tomographyfree navigation in patients with Crowe’s classification stage I or II dysplastic osteoarthritis and to examine the factors affecting the cup installation accuracy. Methods: Using both navigation systems for the same technique, primary total hip arthroplasty was performed by the same surgeon in 36 patients. A cup was installed using computed tomography-based navigation, and the installed cup was measured again using computed tomography-free navigation. We compared the error between the target angle and the intraoperative installation angle for each navigation method by performing statistical analyses. Results: For computed tomography-based navigation, errors in the inclination and the anteversion angles compared to the target angle were 3.14° ± 1.55° and 1.47° ± 0.99°, respectively. For computed tomography-free navigation, the inclination and anteversion angle errors were significantly larger, i.e., 6.84° ± 4.78° and 5.43° ± 5.22°, respectively (p < 0.01). The inclination and anteversion angles of computed tomography-free navigation were correlated, and there were no significant factors influencing the error. Conclusions: Computed tomography-based navigation is more accurate for cup installation than computed tomography-free navigation. When using computed tomography-free navigation, it is necessary to add technical schemes before and during surgery to improve the cup installation accuracy.

치과 임프란트 치료 계획을 위한 나선형 일반 단층촬영과 전산화 단층촬영시 흡수선량 및 유효선량 평가

홍병희,한원정,김은경 대한구강악안면방사선학회 2001 Imaging Science in Dentistry Vol.31 No.3

Objectives : To evaluate the absorbed and effective doses of spiral and computed tomography for the dental implant planning. Materials and Methods : For radiographic projection, TLD chips were placed in 22 sites of humanoid phantom to record the exposure to skin and the mean absorbed dose to bone marrow, thyroid, pituitary, parotid and submandibular glands and nesophagus. Effective dose was calculated, using the method suggested by Frederiksen et al.. Patient situations of a single tooth gap in upper and lower midline region, edentulous maxilla and mandible were simulated for spiral tomography.35 axial slices(maxilla) and 40 axial slices (mandible) with low and standard dose setting were used for computed tomography. All the radiographic procedures were repeated three times. Results : The mean effective dose in case of maxilla was 0.865 mSv,0.452 mSv,0.136 mSv and 0.025 mSv, in spiral tomography of complete edentulous maxilla, computed tomography with standard mAs , computed nomography with low mAs and spiral tomography of a single tooth gap (p〈0.05). That in case of mandible was 0.614 mSv, 0.448 mSv, 0.137 mSv and 0.036 mSv, in spiral tomography of complete edentulous mandible, computed tomography with standard mAs, computed tomography with low mAs and spiral tomography of a single tooth gap (p〈0.05). Conclusions : Based on these results, it can be concluded that low mAs computed tomography is recommended instead of spiral tomography for the complete edentulous maxilla and mandible dental implant treatment planning. (Korean J Oral Maxillofac Radiol 2001; 31 : 165-73)

18F-2-Deoxy-2-Fluoro-D-Glucose Positron Emission Tomography: Computed Tomography for Preoperative Staging in Gastric Cancer Patients

윤석화,윤기영,서경원,이상호,신연명 대한위암학회 2012 Journal of gastric cancer Vol.12 No.3

Purpose: The use of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography-computed tomography as a routine preoperative modality is increasing for gastric cancer despite controversy with its usefulness in preoperative staging. In this study we aimed to determine the usefulness of preoperative positron emission tomography-computed tomography scans for staging of gastric cancer. Materials and Methods: We retrospectively analyzed 396 patients’ positron emission tomography-computed tomography scans acquired for preoperative staging from January to December 2009. Results: The sensitivity of positron emission tomography-computed tomography for detecting early gastric cancer was 20.7% and it was 74.2% for advanced gastric cancer. The size of the primary tumor was correlated with sensitivity, and there was a positive correlation between T stage and sensitivity. For regional lymph node metastasis, the sensitivity and specificity of the positron emission tomographycomputed tomography were 30.7% and 94.7%, respectively. There was no correlation between T stage and maximum standardized uptake value or between tumor markers and maximum standardized uptake value. Fluorodeoxyglucose uptake was detected by positron emission tomography-computed tomography in 24 lesions other than the primary tumors. Among them, nine cases were found to be malignant, including double primary cancers and metastatic cancers. Only two cases were detected purely by positron emission tomography-computed tomography. Conclusions: Positron emission tomography-computed tomography could be useful in detecting metastasis or another primary cancer for preoperative staging in gastric cancer patients, but not for T or N staging. More prospective studies are needed to determine whether positron emission tomography-computed tomography scans should be considered a routine preoperative imaging modality.

18F-2-Deoxy-2-Fluoro-D-Glucose Positron Emission Tomography: Computed Tomography for Preoperative Staging in Gastric Cancer Patients

Youn, Seok Hwa,Seo, Kyung Won,Lee, Sang Ho,Shin, Yeon Myung,Yoon, Ki Young The Korean Gastric Cancer Association 2012 Journal of gastric cancer Vol.12 No.3

Purpose: The use of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography-computed tomography as a routine preoperative modality is increasing for gastric cancer despite controversy with its usefulness in preoperative staging. In this study we aimed to determine the usefulness of preoperative positron emission tomography-computed tomography scans for staging of gastric cancer. Materials and Methods: We retrospectively analyzed 396 patients' positron emission tomography-computed tomography scans acquired for preoperative staging from January to December 2009. Results: The sensitivity of positron emission tomography-computed tomography for detecting early gastric cancer was 20.7% and it was 74.2% for advanced gastric cancer. The size of the primary tumor was correlated with sensitivity, and there was a positive correlation between T stage and sensitivity. For regional lymph node metastasis, the sensitivity and specificity of the positron emission tomography-computed tomography were 30.7% and 94.7%, respectively. There was no correlation between T stage and maximum standardized uptake value or between tumor markers and maximum standardized uptake value. Fluorodeoxyglucose uptake was detected by positron emission tomography-computed tomography in 24 lesions other than the primary tumors. Among them, nine cases were found to be malignant, including double primary cancers and metastatic cancers. Only two cases were detected purely by positron emission tomography-computed tomography. Conclusions: Positron emission tomography-computed tomography could be useful in detecting metastasis or another primary cancer for preoperative staging in gastric cancer patients, but not for T or N staging. More prospective studies are needed to determine whether positron emission tomography-computed tomography scans should be considered a routine preoperative imaging modality.

원인 불명의 위장관 출혈에서 64채널 다중검출 컴퓨터단층촬영, 캡슐내시경, 이중풍선소장내시경의 임상적 유용성

박준석,김진오,김현건,이준성,이태희,안병규,전성란,김민정,유진영 순천향대학교 순천향의학연구소 2011 Journal of Soonchunhyang Medical Science Vol.17 No.2

Objective: Obscure gastrointestinal bleeding primarily originates from small-bowel lesions. It is difficult to detect the lesions by using classical diagnostic modalities, and thus, new methods have been developed. The aim of study was to evaluate the clinical usefulness of 64-channel multidetector computed tomography, capsule endoscopy, and double-balloon enteroscopy for detection of obscure gastrointestinal bleeding. Methods: This retrospective study analyzed the findings of 64-channel multidetector computed tomography, capsule endoscopy,and double-balloon enteroscopy in patients with obscure gastrointestinal bleeding treated at Soonchunhyang University Seoul Hospital between January 1, 2008 and September 30, 2010. Results: Five of 22 positive findings (22.7%) were obtained using 64-channel multidetector computed tomography. The computed tomography could not detect active bleeding lesions but it played an important role on the evaluation of extraluminal lesions. The diagnostic yield of capsule endoscopy was 82.4%. No cases of capsule retention were detected in this study. Bleeding lesions were identified in all cases through the use of double-balloon enteroscopy. One hemoclipping and 2 biopsies were performed. Conclusion: Sixty-four-channel multidetector computed tomography can be used to evaluate extraluminal lesions. Capsule endoscopy is the most convenient endoscopy method. Invasive procedures can be performed using double-balloon enteroscopy. These methods can be used complementarily to diagnose and treat occult gastrointestinal bleeding. Use of capsule endoscopy after screening with 64-channel multidetector computed tomography in the case of patients with occult gastrointestinal bleeding is suggested. In case of lesions wherein invasive procedures are required, use of double-balloon is preferred.

악교정 수술에서 모의 조종된 3차원 전산화 단층촬영상의 응용

김형돈,이경상,유선국,박창서 大韓口腔顎顔面 放射線學會 1998 Imaging Science in Dentistry Vol.28 No.2

In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipments and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of dry skull that position of mandible was displaced, range of displacement between computer-simulated three dimensional images and actual postoperative three dimensional images in co-ordinates values was from -1.8 mm to 1.8 mm and 94% in displacement of all co-ordinates values was from -1.0 mm to 1.0 mm and no significant difference between computer-simulated three dimensional images and actual postoperative three dimensional images was noticed(p>0.05). 2. In four cases of orthognathic surgery patients, range of displacement between computer-simulated three dimensional images and actual postoperative three dimensional images in coordinates values was from -6.7 mm to 7.7 mm and 90% in displacement of all co-ordinates values was from -4.0 to 4.0 mm and no significant difference between computer-simulated three dimensional images and actual postoperative three dimensional images was noticed(p>0.05). Conclusively, computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms. Therefore, potentiality that can construct postoperative three dimensional image without three dimensional computed tomography after surgery was presented.

근골격계 악성 종양 환자의 림프절 전이 발견을 위한 양전자 방출 컴퓨터 단층 촬영기(Positron Emission Tomography/Computed Tomography)의 유용성

신덕섭,나호동,박재우 대한정형외과학회 2019 대한정형외과학회지 Vol.54 No.6

Purpose: Lymph node metastasis is a very important prognostic factor for all skin cancers and some sarcomas. A sentinel lymph node (SLN) biopsy is the most useful technique for identifying SLNs. Recently, a new generation of diagnostic tools, such as single photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/CT (PET/CT) enabled the detection of SLNs. This study compared the efficacy of PET/CT for detecting lymph node metastases with a SLN biopsy in a single medical center. Materials and Methods: From 2008 to 2018, 72 skin cancers of sarcoma patients diagnosed with some lymph node involvement in a whole body PET/CT reading were assessed. Patients suspected of lymph node metastasis were sent to biopsy and those suspected to be reactive lesions were observed. The analysis was performed retrospectively using the medical records, clinical information, PET/CT readings, and pathology results. Results: The age of patients ranged from 14 to 88 years and the mean follow-up period was 2.4 years. Twenty-two patients were suspected of a lymph node metastasis and confirmed. The sensitivity, specificity, positive predictive value and negative predictive value of PET/CT images in sarcoma and non-sarcoma tumors were increased significantly when the expert’s findings were considered together. Conclusion: PET/CT is effective in detecting lymph node metastases. 목적: 악성 종양 환자에서 림프절 전이를 발견하는 것은 초기에 정확한 병기 및 예후와 관련된 정보를 알 수 있고 수술 후 보조치료(adjuvant therapy)의 필요성을 평가해서 조기에 치료를 할 수 있도록 해주기 때문에 중요하다. 본 연구를 통해 정형외과 영역의 악성 종양 환자를 평가함에 있어 양전자 방출 컴퓨터 단층 촬영기(positron emission tomography/computed tomography, PET/CT)가 sentinel lymph node biopsy와 비교하여 유용한지를 알아보고자 한다. 대상 및 방법: 2008년부터 2018년까지 악성 근골격계 종양으로 진단받고 PET/CT를 촬영한 환자 251명 중 72명의 환자를 선별하여 후향적 분석을 시행하였다. 림프절 전이가 의심되는 환자군은 조직검사를 시행하였다. 분석은 의무기록, 임상정보, PET/CT 영상 및 판독 소견, 병리 결과를 통해 시행하였으며, 임상경과 및 병리검사 결과를 PET/CT 결과와 비교하여 PET/CT의 정확도를 평가하였다. 결과: 환자의 나이는 14세에서 88세까지 분포하였고, 평균 추시 기간은 2.4년이었으며, 22명에서 림프절의 전이가 확인되었다. 육종 및 비육종 종양에서 PET/CT 영상의 민감도, 특이도, 양성예측도, 음성예측도는 전문가의 소견을 함께 고려할 경우 상당히 상승하는 것을 확인하였다. 결론:

한국인 남성 무치악환자에서 파노라마 방사선사진상의 치조골 높이 왜곡에 대한 후향적 연구

백주현,송영균 대한구강악안면임플란트학회 2018 대한구강악안면임프란트학회지 Vol.22 No.2

Purpose: The purpose of this study was to analyze the mean residual alveolar bone height according to various measuring points of male edentulous patients. And to compare the residual alveolar bone height differences observed in panoramic and computed tomography images for analyzing the predictable distortion trends in panoramic radiography. Materials and Methods: The study used 40 images of the maxilla and mandible, excluding computed tomography and panoramic images. Based on the anatomical indices, the measurement values of each image were obtained by setting 7 measuring points of the maxilla and 9 measuring points of the mandible. The significant difference was statistically analyzed by paired t test comparing the measurement values observed on computed tomography and panoramic radiography (p <0.05). Results: The mean residual alveolar bone height was more than 15.5 mm in the maxillary anterior part, 8.2 mm in posterior part, 27.7 mm in the mandibular anterior part, and the mandibular posterior part was 11.1 mm. The result of paired t-test comparing the computed tomography and panoramic images showed that the maxillary right central incisor position, maxillary left second premolar, maxillary right second premolar, mandibular left first premolar, mandibular right first premolar, mandibular left second premolar, mandibular right second premolar, mandibular left first molar, mandibular right first molar positions of residual alveolar bone height were significantly different between two images.(p <0.05). Conclusion: It is considered that the reliability of the panoramic radiography is low because there is a significant difference in the residual alveolar bone height observed on computed tomography and panoramic radiography images. Ⅰ. 서론 : 임플란트와 연조직에서 일차 지지를 얻는 보철은 환자의 심미, 기능, 안정, 발음 등에 관한 요구를 만족시켜야 한다. 임플란트 수술 시 보철치료의 필요에 맞는 임플란트의 직경, 수, 위치를 정해야 하며 잔존 치조골의 상태가 중요한 요인으로 작용한다1. 임플란트의 성공에 영향을 미치는 주요 요인은 정확한 수술과 보철 치료계획이며, 치료 계획 중 방사선학적 평가는 필수적인 요소이다2,3. 잔존 치조골의 상태를 방사선학적 평가하는 방법에는 측방 두부규격방사선사진(lateral cephalometric radiography)과 파노라마 방사선사진(panoramic radiography) 같은 다양한 방법이 있다4-8. 이중 잔존치조골 높이 측정 방법에는 파노라마 촬영술과 전산화 단층 촬영술(computed tomography/CT)이 있으며 파노라마 촬영술은 가장 보편적 방법이지만, 이차원 이미지 영상으로 협설 방향의 정보가 부족하고 수평적, 수직적 영상의 확대가 나타날 수 있다9-11. 또한 다양한 확대율을 가진 영상으로 해부학적 구조물의 왜곡이 나타날 수 있으며 촬영 중 환자의 머리 위치에 따라 길이가 달라지는 등 기준을 잡기 어려운 한계가 있다12,13. 전산화 단층 촬영술은 3차원 영상으로 수직적, 수평적 위치 확인이 가능하며 파노라마 촬영에 비해 정확한 해부학적 구조물의 관찰이 가능하나 높은 비용과 방사선 노출량으로 인한 단점이 있다. 임플란트 수술 시 전산화 단층 촬영술 뿐만 아니라 기본 방사선사진을 포함한 검사가 모두 실시되어야 하는데 파노라마 촬영술은 무치악과 유치악 환자 모두에서가장 보편적으로 사용되는 방법이다14,15. 임플란트 수술 시 주의해야 할 해부학적 구조물은 상악동, 이공, 하 치조 신경관 등 다양하며, 특히 신경혈관계는 임플란트 수술 중 침범시에 위험을 초래할 수 있으므로 수술 전 우선적으로 고려해야한다16. 이번 연구의 목적은 한국인 남성 전부 무치악 환자의 다양한 위치에 따른 평균 잔존 치조골 높이를 파노라마 촬영술과 전산화 단층 촬영술 영상에서 비교분석하여, 파노라마 촬영술에서 예측할 수 있는 왜곡경향을 분석함으로써, 파노라마 영상만을 통해 임플란트 수술 시 주의해야 할 해부학적 구조물을 파악하고자 하는 것이다. Ⅴ. 결론 : 본 연구를 통해 전산화 단층 촬영술과 파노라마 촬영술 영상에서 관찰되는 잔존치조골 높이를 비교분석한 결과, 상악에 경우 정중선, 좌측 중절치, 좌측 제1대구치, 우측 제2대구치 위치에서, 하악에서는정중선, 좌측 중절치, 우측 중절치위치에서 파노라마 영상이 신뢰할 수 있을 것으로 사료되며, 그 외 위치에서는 파노라마의 측정 수치가 실제 수치보다 더 높게 나타나는 경향이 있어, 주의가 필요할 것으로사료된다.

Application of Computer-Aided Diagnosis for the Differential Diagnosis of Fatty Liver in Computed Tomography Image

Hyong-Hu Park(박형후),Jin-Soo Lee(이진수) 한국방사선학회 2016 한국방사선학회 논문지 Vol.10 No.6

본 연구는 복부 전산화단층촬영 영상을 이용하여 지방간환자의 영상을 질감특징분석과 ROC curve 분석을 하였으며, 컴퓨터보조진단시스템의 구현을 위한 실험적인 선형 연구로서 전산화단층촬영 영상에서 지방간의 객관적이고 신뢰성 있는 진단 정보를 의사에게 제공하고자 하였다. 실험은 정상 및 지방간 복부 전산화단층촬영 영상을 실험영상으로 하여 설정된 구역에 대한 wavelet 변환을 거쳐 질감의 특징값을 나타내는 6가지 파라미터로 통계적 분석 결과를 나타내었다. 그 결과 엔트로피, 평균밝기, 왜곡도는 90% 이상의 비교적 높은 인식률을 보였고, 대조도, 평탄도, 균일도는 약 70% 정도로 비교적 낮은 인식률을 나타내었다. ROC curve를 이용한 분석에서 6가지의 파라미터 모두 0.900(p=0.0001)이상을 나타내어 질환인식에 의미가 있는 결과를 나타내었다. 또한 6가지 파라미터에서 질환 예측을 위한 cut-off 값을 결정하였다. 이러한 결과는 향후 복부 전산화단층촬영 영상에서 질환 자동검출 및 최종진단의 예비 진단 자료로서 적용 가능할 것이다. In this study, we are using a computer tomography image of the abdomen, as an experimental linear research for the image of the fatty liver patients texture features analysis and computer-aided diagnosis system of implementation using the ROC curve analysis, from the computer tomography image. We tried to provide an objective and reliable diagnostic information of fatty liver to the doctor. Experiments are usually a fatty liver, via the wavelet transform of the abdominal computed tomography images are configured with the experimental image section, shows the results of statistical analysis on six parameters indicating a feature value of the texture. As a result, the entropy, average luminance, strain rate is shown a relatively high recognition rate of 90% or more, the control also, flatness, uniformity showed relatively low recognition rate of about 70%. ROC curve analysis of six parameters are all shown to 0.900 (p = 0.0001) or more, showed meaningful results in the recognition of the disease. Also, to determine the cut-off value for the prediction of disease six parameters. These results are applicable from future abdominal computed tomography images as a preliminary diagnostic article of diseases automatic detection and eventual diagnosis.